When migrating from pre-5.0 releases, are there any guidelines? Code that needs to be changed, "gotchas" to look out for, etc.
Thanks.

When attempting to compile/install the D-and-D Component Suite 5 in D5 I get two errors:

"Cannot find the resource file …DragDropD5.res. Recreated" (which is a minor problem…)

and a fatal error: "Could not create output file …\DropSource.dcu".

The package fails to install.

Is there a problem somewhere?

great work! would you consider about creating an online svn/cvs repository?

Excelent component! I'll be using it from now on..
P.S. A lot of demo apps are raising weird exceptions at startup. Please, have a look. I'm using Delphi 7 on Windows 2003 Server R2..
The DropTarget component is working easy and nice as it's supposed to.
Congratulations for your great work!

Just downloaded and tested some of your demos. In the file source demo I can drag files FROM my application into any Windows Explorer window, except on the desktop. Why? Isn't the windows desktop just another instance of explorer.exe?
What am I missing?

Regarding the SourceDemo

Can the following two kinds of drag'n'drop co-exisit:

1. Drag the ListView items to other applications, eg Explorer   (this is a behavior of the SourceDemo)

2. If the user drag'n'drop the ListView items within the ListView, I want the items to be re-sorted.

Please advise. Thank you.

Thanks for your components it is a wonderful gift To the community but..
it fails to compile so does not install.

[DCC Error] DragDropText.pas(325): E2011 Low bound exceeds high bound

function MakeRTF(const s: string): AnsiString;
...
begin
...
      c := p^;
      cAnsi := AnsiChar(c);
      if (Ord(c) <= 127) then // Char is ANSI
      begin
        case cAnsi of
        '\', '{', '}':
          Result := Result + '\' + cAnsi;
        Chr(9):
          Result := Result + '\tab ';
        Chr(13):
          Result := Result + '\par ';
        Chr(0)..Chr(8),
        Chr(10)..Chr(12),
        Chr(14)..Chr(31),
        Chr(127)..Chr(255):   <<<--- HERE
          Result := Result + AnsiString(Format('\"%.2x', [ord(c)]));
        else
          Result := Result + cAnsi;
        end;
...

I hope you can fix it soon .
Merry Christmas - Peace
Philippe Watel

Hello. I trying to make drag&drop images from browser to my program.
using DropComboTarget.

With Firefox it works fine. I get Bitmap and working with it, but with IE and Chrome i got only Text and Url when drop image. I tried to look at Source Analyzer Demo: when i drop image from
Chrome i got "filecontents" and this is content of dropped image, but in DropComboTarget i got only Text & Url … (sorry if my English was bad, hope u understand me )

hi
delphi 2010 but i tried with 2009 and it was the same
bye
PW

We have same error happened as [DCC Error] DragDropText.pas(325): E2011 Low bound exceeds high bound. But It's OK now after modify those code from you.

Hello!

Delphi 2009, component TDropFileSource.

In popup menu:

• Copy -OK
• Move - OK
• Create Links - do not work

This works beautifully in Delphi 6 but …

I had a lot of trouble getting this to install. I am now having to reinstall my system after a crash and so far have not been able to pesuade Delphi to compile D & D again (yes the folder does exist per above comment by David).

Thank you for this package. I appreciate the work put into its creation as I was part way through trying to work this out myself when I found your components.

Hello,

I have an application which will get all the email addresses in the server, and put them in the listview. Now I want this email addresses could be dragged from my listview to contacts in Outlook 2007.

could this be possible?

thanks and best regards

Hello.  My program is using Version 4 of the toolkit, and, based on ExtractDemo, I've been working on having it allow the user to drag a .WAV file within the program onto a target location, including other apps that accept .WAV files dropped onto them.  

My program renders the file at the time the file dropped to the target location, when  DropFileSource1Drop is executed by my program.   This works fine for some apps, however, in testing, there are reports that it doesn't work for some apps.  One target app that I tested appears to require a fully-formed valid file to be present on disk at the time the mouse cursor is moved over it, otherwise the mouse cursor stays at "no drop allowed" cursor.   Windows Media Player had a similar problem, in that it required a file with the target name to be present on disk, but I was able to get my program to drop into WMP by creating a small dummy file with the target file name, before DropFileSource1.Files.Add and DropFileSource1.Execute are called.  Then, when the DropFileSource1Drop method is executed to do the actual drop, my program just erases the dummy file and re-creates it and WMP received it.   

The problem:  Unlike Windows Media Player, this other program requires the dummy .WAV file to be a VALID .WAV in order for the mouse cursor to indicate the program will accept the file, but if I try erase the file and then recreate it during DropFileSource1Drop, or if I have my program attempt to open the existing file and add to it, then it won't work because the other program (or windows) has taken control of the file and blocked my app from accessing it or erasing it. 

Wondering if there is any solution to this problem?   How can I prevent the target app from taking control of the file before the DropFileSource1Drop is executed?  Also I am curious how the target app even knows the name of the file when the mouse cursor is hovering over the app, but before DropFileSource1Drop is executed?

Thanks,

Jeff

Hi! I've found your components tonight and am amazed. Thanks for the massive amount of work. However, I have to issues trying to simulate file-Drag&Drop from my application to a foreign target application that does not accept data from remote otherwise:

1. Is it possible at all to programatically drag and drop files to the target without moving the mouse cursor to the target "in real-time" with SetCursorPos?

2. The target seems to accept drops from Windows Explorer only. What is so special about Explorer that it can be identified by the target? How can I mimic Explorer's behaviour? Tomorrow, I will use your Source and Target analyzers to find out differences between my DataObjects and those of Explorer. Anyway, if you have an idea, any help is appreciated.

Hello, i just tried this one with D2005, using the include path to the source. I took that TargetDemo of the Demos, and modified it, since i can't include packages to my Delphi IDE because of the Delphi version.This one works fine with D5000 ! You should add something like the following, if you can't add packages like me:

procedure TForm1.FormCreate(Sender: TObject);
begin
  DropFileTarget1 := TDropFileTarget.Create(self);
  DropFileTarget1.Enabled := true;
  DropFileTarget1.OnDrop := DropFileTarget1Drop;
  DropFileTarget1.DragTypes := [dtCopy, dtMove, dtLink];
  DropFileTarget1.Target := Listview1;
  DropFileTarget1.OptimizedMove := True;
end;
 
procedure TForm1.FormDestroy(Sender: TObject);
begin
  DropFileTarget1.Free;
end;

I have confirmed that these components ARE compatible with Delphi 2006.

By the way… nice job!!!!    And much appreciated.

Is there a way to know the source application?

I mean whether there is a way to know from which application, say WORD, EXCEL, Internet Explorer or FireFox, the data is dragged?

Thanks in advance.

Downloaded the DragDrop components, awesome. Ran the Outlook demo with Delphi 6, everything worked great. Ran the Outlook demo with Delphi 2010, the opening of attachements isn't working (ActionAttachmentOpenExecute). Saving the attachment appears to be failing, yet I'm not getting any errors. I have rights to the directory, not an expert with streams….any ideas?

Great suite.
I am trying to make some simple copy/paste but I would like to copy a stream into the clipboard to be paste onto Explorer as a file. Is there any specific example in which this capability can be visualized ?
I am also thinking about how to create a shell handler to transfer this files directly by drag'n'drop (my application actually has the files centralized in a server and each time I need to open or copy them it is a remote operation, so they need to be downloaded first). Will appreciate any help… Thanks !

Many thanks for the Drag & Drop Components (also TGIFImage).  Your hard work is appreciated (glad it was fun!)

I compiled the Drag & Drop Components into my Delphi Turbo Explorer (2006) application and they have worked fine on Windows XP for some time now, however when I installed the application on a Windows 2000 system they don't seem to work.  Is there something else I need to install?  (I use this application to drag emails and attachments from Outlook 2003 to my application on the XP system, but I'm using Outlook Express from IE6 SP1 on the 2000 computer).

Thanks

Hi,
thanks for your components…

"Simple Source Demo" can't Drop files to Explorer or Desktop on Windows 7(32). A Dos-Box accept files.

Thanks

Using DragDrop component suite with a dynamic package runtime package may cause memory leak.  I have create a sample project to show the leak, please download from here.

This sample project built with Drag and Drop component suite version 5.1 in Delphi 2007.

The memory leak should occurs in a method TCustomSimpleClipboardFormat.DoSetData of unit DragDropFormats.pas:

function TCustomSimpleClipboardFormat.DoSetData(const FormatEtcIn: TFormatEtc;
  var AMedium: TStgMedium): boolean;
var
  p: pointer;
  Size: integer;
  Global: HGLOBAL;
  Stream: IStream;
  OleStream: TStream;
begin
  Result := False;
  ...
  if (Size <= 0) then
    ...
    exit;
      OleStream := TOLEStream.Create(Stream);
      Stream := TFixedStreamAdapter.Create(OleStream, soOwned) as IStream;
 
      IStream(AMedium.stm) := Stream;
    except
      Result := False;
    end;
    ...
    Result := False;
end;

An instance of TOLEStream and an instance of TFixedStreamAdapter cause the leak.

The memory leak only occurs if DragDrop components used in this dynamic runtime package behavior.
It doesn't happen if using DragDrop in static binding package.

I recently purchased Rapware's EasyMapi components and was wondering if it's ok to modify your DragDropInternet.pas to work with Rapware's mapi units? Would a better approach be to make my own TEasyMapiOutlookDataFormat object in it's own unit instead?

I'm looking for both it's ok to do this answer and this would be easier/better answer.

Daniel

Hi Anders,
Thank you for the new version of Drag and Drop Component Suite. I'm a paid customer of Raize DropMaster because at an earlier time Drag and Drop Component Suite was lack of a function I needed (although I cannot remember what that was it) But now things have been changed, Raize DropMaster does not support UNICODE in pre-2009 versions of Delphi, but your excellent component suite does! and yours offers almost all features I needed! Thank you!
One question if you don't mind, the TVirtualFileStreamDataFormat.FileNames property is TStrings instead of TUnicodeStrings, do you have a plan to add UNICODE support to this class?
Thank you.

Hi, a remark regarding the OnDrop Event: the function TCustomDropTarget.Drop catches all exceptions. It should IMHO not catch exceptions that occur in the user defined callback.

I have just started using this component and I love it.  I am working on an interface to allow a user to drag an email to it and then  I will save the email in a specific folder. 

I have used the OutlookDemo as a model

I can see the IMessage object and am able to extract the subject, attachments, and sender etc

I am hoping that there is a simple method I can use like AMessage.SaveAs ('c:\test.msg') or AMessage.export ('c:\test.msg').

I am using Delphi 2009.

Thank you

Great product. Thank you!

I have 2 questions.

How can I retrieve, in the OutlookDemo (OutlookTarget.pas) the Message ID and the Message Received Time?

I am unable to get these to values. I was using PR_MESSAGE_DELIVERY_TIME and PR_ENTRYID.

Thank you

Hi Anders,
I found the the TDropFileSource.MappedNames does not work with Outlook 2007, although it works with the Windows Explorer, any comment about this? Thank you.

TObject.Free v.s FreeAndNil
I think the code in TOutlookDataFormat.Destory is backwards. Instead of calling inherited Destroy first, IMHO destructors should always call it last after freeing their own resources.

destructor TOutlookDataFormat.Destroy;
begin
  inherited Destroy;  //<—- Should be called last
  FMessages.Free;
end;

In the case of the TOutlookDataFormat calling inherited Destroy last, will cause an access violation. This is caused by the following chain of events.

TOutlookDataFormat.Destroy
   TMessages.Destroy
     TMessages.Clear
     TMessages.FMessages.Free
(Inherited)
   TStorageDataFormat.Destory
   TStorageDataFormat.Clear – (polymorphism calls TOutlookDataFormats.Clear method here, which then tries to access FMessages member which has already been freed.)

I don’t think the Clear methods are ever called outside of the DragDropInternet.pas unit, but in any case by changing the TOutlookDataFormat.Destroy to use FreeAndNil you could then change the TOutlookDataFormat.Clear method to test for nil. Thereby correcting the aforementioned access violation assuming you correct the destructor to call inherited Destory last.

destructor TOutlookDataFormat.Destroy;
begin
  FreeAndNil(FMessages);
  inherited Destroy;
end;

procedure TOutlookDataFormat.Clear;
begin
  inherited Clear;
  if FMessages <> nil then
    FMessages.Clear;
end;

Just my thoughts…

PS: Ever think about setting up a newsgroup instead of these comments?

Compiler Warning:

In the TDropContextMenu.Initialize I'm getting a warning saying return value might be undefined. Do you see a problem with moving Result := NOERROR to the top of the method?

function TDropContextMenu.Initialize(pidlFolder: PItemIDList;
  lpdobj: IDataObject; hKeyProgID: HKEY): HResult;
begin
  Result := NOERROR;
{$ifopt D+}
  OutputDebugString('IShellExtInit.Initialize');
{$endif}
  FFiles.Clear;
  SetFolder(pidlFolder);  // Save a reference to the source data object.
  FDataObject := lpdobj;
  try
    // Extract source file names and store them in a string list.
    // Note that not all shell objects provide us with a IDataObject (e.g. the
    // DirectoryBackground object).
    if (DataObject <> nil) then
      with TFileDataFormat.Create(dfdConsumer) do
        try
          if GetData(DataObject) then
            FFiles.Assign(Files);
        finally
          Free;
        end;
    if (Assigned(FOnPopup)) then
      try
        FOnPopup(Self);
      except
        Result := E_UNEXPECTED;
        exit;
      end;
  finally
    FDataObject := nil;
  end;
end;

How can my application (main form) be a droptarget for both files and outlook objects?

Hello! In windows7 use Drag and Drop Component Suite Version 5.1 have been if the program using the Run as administrator can not be realized drag and drop! ! !

I'm trying to follow your reply to this comment where the files don't exist when the drag drop starts but get created on the GetData and OnDrop events.

Do I still populate the TDropFileSource.Files before I call TDropFileSource.Execute or should I populate the TDropFileSource.Files in one of the events like GetData?

Email Attachments

I can't seem to figure out how to get my application to accept email attachments if I drag the attachment from an open email window (outlook 2007). I'm not dragging the email, just the attachment in the email. Any ideas?

Hi, guys, I have a problem but I have no place to ask for help.
I have used the following code to get the HTML Format code of a webpage:

function TForm1.GetTextFromObj(const DataObj: IDataObject;
  const Fmt: TClipFormat): String;
var
  Medium: TStgMedium;
  PText: PAnsiChar;
begin
  if DataObj.GetData(MakeFormatEtc(Fmt), Medium) = S_OK then
  begin
    Assert(Medium.tymed = MakeFormatEtc(Fmt).tymed);
    try
      PText := GlobalLock(Medium.hGlobal);
      try
        Result := PText;
      finally
        GlobalUnlock(Medium.hGlobal);
      end;
    finally
      ReleaseStgMedium(Medium);
    end;
  end
  else
    Result := '';
end;

but unfortunately, some of the HTML Format code snippets are unreadable.
examples here:

Version:0.9
StartHTML:00000151
EndHTML:00000893
StartFragment:00000185
EndFragment:00000857
SourceURL:http://blog.ifeng.com/article/4665556.html
<html><body>
<!–StartFragment–> ?????€???????<!–EndFragment–>
</body>
</html>

It is dragged from a Chinese webpage. But the part between StartFragment and EndFragment cannot be read.

I am sure there must be one solution to this, but i can't find it. I would be grateful if any advice is given.
Thanks in advance.

If I have two data format adapters on a form that prompt the user during the OnDrop event for both formats, I can get it to error out in a rather unlikely scenario. In this example I'm using TOutlookDataFormat and a TFileDataFormat adapter.

1) Drop an email on the form, leave the modal dialog unanswered.
2) Now drop a file on the form and try to answer the modal dialogs.
 
This results in an AV. I've tried to disable the TDropEmptyTarget but it still lets me drop while I'm in the OnDrop event.

unit Unit1;
interface
uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, DragDrop, DropTarget;
type
  TForm1 = class(TForm)
    DropEmptyTarget1: TDropEmptyTarget;
    DataFormatAdapterFile: TDataFormatAdapter;
    DataFormatAdapterOutlook: TDataFormatAdapter;
    procedure DropEmptyTarget1Drop(Sender: TObject; ShiftState: TShiftState; APoint: TPoint; var Effect: Integer);
  private
    { Private declarations }
  public
    { Public declarations }
  end;
var
  Form1: TForm1;
implementation
uses DragDropInternet, DragDropFile;
{$R *.dfm}
procedure TForm1.DropEmptyTarget1Drop(Sender: TObject; ShiftState: TShiftState;
 APoint: TPoint; var Effect: Integer);
var
  OutlookDataFormat: TOutlookDataFormat;
  FileDataFormat: TFileDataFormat;
begin
  DropEmptyTarget1.Enabled := False;
  try
    if DataFormatAdapterOutlook.DataFormat <> nil then
    begin
      OutlookDataFormat := DataFormatAdapterOutlook.DataFormat as TOutlookDataFormat;
      try
        ShowMessage( 'Doing something with the outlook data.' );
      finally
        OutlookDataFormat.Clear;
      end;
    end;
    if DataFormatAdapterFile.DataFormat <> nil then
    begin
      FileDataFormat := DataFormatAdapterFile.DataFormat as TFileDataFormat;
      try
        ShowMessage( 'Doing something with the file data.' );
      finally
        FileDataFormat.Clear;
      end;
    end;
  finally
    DropEmptyTarget1.Enabled := True;
  end;
end;
 
end.

Hi,

I want to detect if a file has a specific file format before allowing it to be dragged onto my application.  Is this code safe, or is there a better way to do it?  I'm a little concerned about the call to .clear, should that be there if my program refuses the file?

procedure TForm1.DropEmptyTarget1Enter(Sender: TObject; ShiftState: TShiftState; APoint: TPoint; var Effect: Integer);
var
  OutlookDataFormat: TOutlookDataFormat;
  bIsValidOutlookDataFormat: Boolean;
begin
  bIsValidOutlookDataFormat := TOutlookDataFormat(DataFormatAdapterOutlook.DataFormat).HasValidFormats(DropEmptyTarget1.DataObject);
  if bIsValidOutlookDataFormat then
  begin
    OutlookDataFormat := DataFormatAdapterOutlook.DataFormat as TOutlookDataFormat;
    bIsValidOutlookDataFormat := (OutlookDataFormat.Messages.Count > 0);
    OutlookDataFormat.Clear;
  end;
end;

Thanks

Hello,
I try to use OutlookDemo. But i've a problem when i drop a mail message on it.
only one message and i've a blank memo and nothing is display. more than one Access Violation and nothing is display
I'm using Delphi 2009 and Outlook 2000 under XP/SP2
In debug 
      // Get an IMessage interface
      if (Supports(OutlookDataFormat.Messages[i], IMessage, AMessage)) then
      begin
        try
          Item := ListViewBrowser.Items.Add;
          … GetSender and GetSubject    - > Return always ''
                                    because if (Succeeded(HrGetOneProp(AMessage, PR_SUBJECT, Prop))) always False
          GetTime(AMessage);              — > return a good day but a  bad      time same with PR_MESSAGE_DELIVERY_TIME
          Item.Data := TMessage.Create(AMessage, OutlookDataFormat.Storages[i]);
    …
also in function ViewMessage
for j := 0 to Rows.aRow[i].cValues-1 do
          begin
{$ifdef UNICODE}
            { TODO : TSPropValue.Value.lpszW is declared wrong }
            Value := PWideChar(Rows.aRow[i].lpProps[0].Value.lpszW);   – > EAccessViolation (item.data)
{$else}
Thanks for your help, i don't know what to do

I really like your Drag & Drop component 5.1 but I am not able to use it under the Creative Common license.  I need a royalty free license that will allow me to use it in a closed source commercial application.  Are you open to licensing it under alternate license in a conventional Delphi component model?  If so how much would you license it for per developer?  Thanks.

Hi, I'm tried this package on Delphi 5. All works fine for me, thank You. But I'm find one big problem. Your components / demos does not work on Windows 7 64bit (tested on Outlook demo), the form does not accept drag. Please correct this.
Thank You, Petr

I'm looking at replacing my drag drop event that contains a loop which requires user interaction for each file dropped on the form. From everything I've read (and one of your previous posts) it's not good to do something modal in the OnDrop event because I'm holding up the shell's thread.

I've tried PostMessage to self but the DataFormatAdapters are empty by the time my message handler fires. Do I need to save down the files myself to a temp location and process them in my message handler or is there a better way to accomplish this?

procedure TForm1.DropEmptyTarget1Drop(Sender: TObject; ShiftState: TShiftState; APoint: TPoint; var Effect: Integer);
begin
    if DataFormatAdapterFile.DataFormat <> nil then
    begin
      FileDataFormat := DataFormatAdapterFile.DataFormat as TFileDataFormat;      for x:=0 to FileDataFormat.Files.Count-1 do
      begin
         // Do something modal for each file
      end;      FileDataFormat.Clear;
    end;
end;

Daniel

Hi Anders,

Thanks for a great set of components. Have you thought about providing them for Lazarus (Free Pascal) which could allow development for Macs?

Thanks Anders - I understand your position.
I think you are wrong about Lazarus users not seeming to care though as I've now had a closer look at the Lazarus IDE and the good news is - there's a Form Boolean property called AllowDropFiles which allows easy drag and drop straight on to a form from another application window.
The feature is really easy to set up - there's no need to set DragMode or write any code for DragOver and DragDrop events. The only thing you have to do is write the code for the OnDropFiles event.
This is quite an impressive feature which does not appear to exist in the versions of Delphi that I've seen (D1 to D2009).

Thank You! Great Job!
————————–

Missed file in current release of DragDrop (20100129):

DragDrop\Demos\ShellContextMenuHandler\About.rc

Love this component, but……
Recently upgraded to D2010 Architect. Installed version 5.1. Demo Project ComboTargetDemo, compiled and ran. From Outlook 2003 dragged attachment(text file) straight from email to drop area. Filename (DropComboTarget1.Data.names[i]) is empty. Data is intact.
Reproduced from more than one machine.

Hi Anders,

I'm looking forward to the new release when it's ready.

I found a problem with TDropContextMenu. Maybe it's among the changes you've already made and in that case you can skip this post cause you probably have a better soluton than I. When the context menu contains more than one level of submenus the wrong clickevent could be fired. After looking for bugs in my code, I tracked it down to GetMenuItem not returning the MenuItem that was actually clicked.
I interpreted it as all items not being counted when getting ItemIndex from LoWord(lpici.lpVerb). Maybe you have a better clue to what's really going on?

I've solved the problem by creating a new function GetClickedMenuItem in "DragDropContext.pas" and calling it instead of GetMenuItem from within InvokeCommand. So far it's been working and I've tested it with up to four submenu levels. Here's what the function looks like:

function DoGetMenuItem(Menu: TMenuItem): TMenuItem;
  var
    i: integer;
  begin
    i := 0;
 
    Result := nil;
    while (Result = nil) and (i < Menu.Count) do
    begin
      if (Menu.Items[i].Visible) then
      begin
        if (Index <= 0) and (Menu.Items[i].Count = 0) then
          Result := Menu.Items[i]
        else if (Menu = FContextMenu.Items) or (Menu.Items[i].Count = 0) then
          //Only decrease index if menuitem is on top level, or doesn't have a submenu
          Dec(Index);
 
        if (Result = nil) then
        begin
          if (Menu.Items[i].Count > 0) then
            Result := DoGetMenuItem(Menu.Items[i])
          else if (Index <= 0) then
            Result := Menu.Items[i];
        end;
      end;
      inc(i);
    end;
  end;
 
begin
  inc(Index);
 
  if (FContextMenu <> nil) then
    Result := DoGetMenuItem(FContextMenu.Items)
  else
    Result := nil;
end;

Hi, I just found Drag&Drop. Very nice. Can I donate some money, maybe $100? Do you take VISA?

What would help is a doc that explains a few things. I need to figure out what that TDropDummy item is all about. The Async mode makes sense but I need to understand the issue areas. (I am not a TThread expert, yet.)

Thanks,
Bob Kondner

PS: I write some software used in electronic assembly. Just 1 guy with a shop and a small set of customers. But I do think I have some good ideas for the electronic design marketplace.

Thanks Anders. The change in TraverseMenu is working well. I've succesfully used it in Delphi 7, 2007 and 2010.
I'm glad to get rid of the procedure I added.

Hi, maybe this problem is already solved and I did not find the solution. But in the demos when a file is MOVED with TDropFileSource from a ListView to Windows Explorer the ListView is not refreshed to indicate that the source files have been deleted. I've searched for an event to handle this but did not find one, also the OnAfterDrop event does not work for this purpose. Any advice?

Hi,
 I was looking through the DropComboTarget and I understood all the drop types except "mfData".

 It is read in via a stream. Can you tell me what common apps might generate this format? I assume it is for passing large sextions of data?

Thanks,
Bob Kondner

Hi,

The context menu component does not work in Windows 7 64 bit.
After the dll has been registered, the menu doesn't appear in the explorer. It works perfectly in 32bit version.
Is there any special treatment for windows 64bit version ?

Thanks,
Armin

Hi,
 On ocassion when debugging an app, the app nolong responds that it can accept a drop. Restart of app or Delphi does not help. A machien Restart helps. I probably trashed the drag thread. Any ideas What would do that? The drop even stores the droped info in a variable and returns. A timer is used to start the priocessing of the drop.

Any ideas where I went astray?

Thanks,
Bob Kondner

hi i found the dragdrop component, works great.

i use the TDropComboTarget the only thing i noticed i cannot drop on non std delphi components like a virtualtreeview ? Can i do anything about that ?

Hi,
I am looking for a solution which can dragdrop
virtual files and folders which from ftp into explorer, 
the example asyncSource  very similar to it?
but the example only write stream to files ,
It  can not creat folders .
I saw TDataformatAdapterSource has 
DataFormatName –> TPIDLDataFormat
Did you have example about it ?

When debugging in Delphi 2010 (CustomFormat1 demo) I notice that dragging to anywhere else but the correct spot locks up the program and the IDE. When program is killed in the Task Manager the IDE comes to life again. When the program exe is run outside of IDE it works like its supposed to. This makes debugging difficult.

Hi,

 I was working with a TDropComboTarget object and I noticed that a drop of a URL from IE8 results in a Text property with a lot of zeros on the end. I saw your notes about some apps passing binary data and I saw the TrimZero property in TCustomAnsiStringClipboardFormat . Is this TrimZeroes the "Correct" way to resolve the extra Zeros. I was taking them out myself but that seems like a hack.

When it comes to OOPs design in Delphi I am still at Bozo level, could you explain how I access that TrimZeros prperty from the applications level. It seems deeply buried down in the base class.

Also, I would also like to extract the filename from a drop of an Outlook attachement. The data I can read using your example code the Name comes in blank. Can you point me in the right direction to implement this in the TDropComboTarget framework. Again, I realize  this might not be the "Correct" location though the TDropComboTarget seems like such a nice application interface point. I can see the file name in the  FileGroupDescriptor I just do not see it surfaced in the TDropComboTarget. I would think it should end up in Data.Names property.

Thanks,
Bob Kondner
PS: You have two wish list items on the way. The US wish list needs an address, I could not ship from the US list. I used the UK list.

Melander,

I want to thank you for providing these components. They are a big help for a lot of us.

There seems to be a bug in the TDropComboTarget component when used in D2010.

When dragging a FileContents stream (in my case, from an attachment on an Outlook email) to my application, the name of the attachment is returned as an empty string. This DOES work okay in Turbo Delphi 2006. The name is what gets lost, the file stream itself seems to be okay.

My system is:

• Windows 7
• Outlook 2003 with an email with an attachment (the drag source)
• Delphi 2010 / Turbo Delphi 2006
• Drag and Drop Components 5.1

To re-produce the bug:

1. Create a new VCL forms project
2. Add a label (Label1) to the form
3. Add a Form OnCreate Event.
   Fill in the following code:

   unit MainUnit;
    
   interface
    
   uses
     Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
     Dialogs, DragDrop, DropComboTarget, StdCtrls;
    
   type
     TMainForm = class(TForm)
       Label1: TLabel;
       procedure FormCreate(Sender: TObject);
     private
       combo_drop_target: TDropComboTarget;
       procedure DropAttachment(Sender: TObject; ShiftState: TShiftState;
         APoint: TPoint; var Effect: Integer);
     end;
    
   var
     MainForm: TMainForm;
    
   implementation
    
   {$R *.dfm}
    
   procedure TMainForm.FormCreate(Sender: TObject);
   begin
     combo_drop_target := TDropComboTarget.Create(Self);
     with combo_drop_target do
     begin
       Name := 'combo_drop_target';
       DragTypes := [dtCopy, dtLink];
       OnDrop := DropAttachment;
       Target := self;
       OptimizedMove := True;
       Formats := [mfData];
     end
   end;
    
   procedure TMainForm.DropAttachment(Sender: TObject; ShiftState: TShiftState;
     APoint: TPoint; var Effect: Integer);
   begin
     Label1.Caption := combo_drop_target.Data.Names[0];
   end;
    
   end.

4. Compile and run the above program.
5. From outlook, find an email with an attachment, then drag that attachment to the program and drop it on the form.

If it works correctly, “Label1” will be replaced with the file name of the attachment. If it doesn’t work correctly, the label caption will go blank.

For whatever it is worth, the TDropEmptyTarget and TDataFormatAdapter combination does properly pick up the attachment file name in the FileNames property in this situation.

Thanks, David Hawk

After preparing this post, I noted it is similar to Bob Kondner’s post a couple days ago. I have provided a simple example to re-create the problem, and a suggestion that TDropEmptyTarget and TDataFormatAdapter might be used instead - a possible workaround for Bob, see the VirtualFileStream demo. Meanwhile - I hope you are enjoying your vacation!

Bob,

Melander might have a better answer when he gets back from vacation, but I had the same problem (no filename from the drop of an Outlook attachment), and was able to get something working using TDropEmptyTarget and TDataFormatAdapter.  Look at the VirtualFileStream demo and look at the code in the DropEmptyTarget1Drop method in main.pas.  The FileNames[] property works properly here.

Best,
David Hawk

David,

 Thanks for the idea, I did start with that approach but I am not yet at the level to completely understand how I would interwork the Adper class with the Drop Combo class. The Combo is so close and I would like to do something useful like maybe add the Outlook name surfacing to the Combo. That would be useful for everyone.

 But, I need some pointers before I can do any serious useful work. And I need a few more read throughs on these tools in general. I am just not at the required level, yet!

Thanks,
Bob Kondner
rkondner circlewitha indexdesigns period_com

Hi Anders,

I just upgraded to version 5.1 of your great drag and drop components Suite. There are two issues in droptarget.pas which you may or may not want to fix. It is hard to say when something is a feature and when something is a bug

1. DragOver is not called when DragEnter returns DROPEFFECT_NONE.

   You write in line 530 in Droptarget.pas > TCustomDropTarget.DragEnter()

   530 531 532

   // If IDropTarget.DragEnter returns with dwEffect set to DROPEFFECT_NONE it // means that the drop has been rejected and IDropTarget.DragOver should // not be called (according to MSDN).

   First, I can not find this anymore on MSDN (maybe Microsoft removed it), but most importantly not calling DragOver causes a problem in some situations.

   My application contains an component with thumbnails. When I drag one thumbnail over another to sort them, I do not want to accept drops on the dragged thumbnail itself, but only on the other thumbnails. I use OnGetDropEffect to determine where dropping is allowed.

   With the current code when I start dragging a thumbnail it is rejected in DragEnter because the thumbnail is dragged over itself. Now when I move the cursor to the neighboring thumbnail the drop is still not accepted because DragOver is never called due to the initial rejection. This is why I commented this code out:

   Droptarget.pas >  TCustomDropTarget.DragEnter(), line: 536

   536 537

   // if ((dwEffect and not(DROPEFFECT_SCROLL)) = DROPEFFECT_NONE) then //  FDataObject := nil;

2. FNoScrollZone only calculated in DragEnter

   FNoScrollZone is only calculated in DragEnter. However, sometimes a component resizes while dragging causing scrollbars to appear while dragging. In this case scrolling does not work.

   An example of a resizing component is a treeview where nodes autoexpand while dragging over them. FNoScrollZone should be calculated in DragOver too. Or it should be recalculated when a component that is dragged over resizes.

Those are two rather exotic cases so I can understand it if you leave things as they are.

Been using your componet for a while - its great! However, we have found it doesn't work to well in windows 7. XP yes, windows 7 no - don't know about vista. Even in your outlooktarget demo it doesn't recognize that a drop can occur.

Any ideas?

Thanks in Advance

Hello Anders,
First of all, thank you for having developed these highly useful components.

I have a technical question about the Async Data Tranfer - Drop Target demo.  In its current state, this demo app accepts only files from Outlook.
What change would be required for this app to accept also files from Windows Explorer? The answer may be quite simple. In any case I hope to be able to use the demo project as a starting point for my project and I am willing to pay for assistance. At this moment, however, I am stuck.

Thank you for your help.
Kind regards,
Stefan

Just discovered what  the problem is. If you are trying to drag and drop under windows 7 (probably vista too) both dragger and dropper needs to be at the same security level. i.e. administrator,administrtor, or user,user. If they are not at the same level drag and drop doesn't work.

Thank you. I need one more piece of advice to be able to get started.

I use the AsyncTransferTarget as a basis for my application. The purpose is to  transfer files to a network folder. Files have to be moved physically from Outlook to a folder.
In the AsyncTransferTarget demo application, I do not see where and how I have to modify the code or settings to achieve this. I am overlooking something obvious. If I do, I apologise for my lack of knowledge. I have not been able to deduct from the VirtualFile demo either how to do this.
A code snippet would be very useful.
Thank you.

Does anyone have an example for handling message and file attachment drops from Thunderbird v3?

Hi, Melander
I can't find the right way to install these components into radstudio 2010.
My step is
Open DragDropD2010.dpr, and then select "Generate all C++ Builder files (including package libs)"

and added some paths to delphi and bcb paths.

then install .
When using in delphi ,every thing is ok.
But if I use it in bcb, there will be errors like this
"[ILINK32 Error] Fatal: Unable to open file 'DRAGDROP.OBJ'"
There is only dragdropd2010.lib in library fold ,no any obj files.
How to solve problem and using these components in both delphi and bcb 2010?
thanks

The detailed error messages are as follows

[BCC32 Error] Dragdropcomobj.hpp(28): E2303 Type name expected
[200 lines of irrelevant error messages snipped]

Hello Anders,
thanks for good demos of the great components you've developed.
I am working with the Outlookdemo an tried to reload a msg file from Filesystem which i previosly saved with FCurrentMessage.SaveToStream.
Is could not figure out how to implement a analog LoadFromStream / File to add the Message in the Demo.

Can you give me a hint , so i can find my way
Thanks

Hi
I using your componet drag and drop. For me are the best. But i have problem with microsoft office 2010. I can't drag any information from this version. Can You help me ?

Hi,

I have a TTreeView that represents a list of files.  On the TreeView's MouseDown event, I'm calling a TDropFileSource's Execute event, and everything works well if the node is dragged off the TTreeView. 

However, I need to allow nodes to be dragged within the TTreeView because the users can rearrange files.  When this happens, some strange behavior occurs: the whole TTreeview is in "don't accept" mode until the mouse button is let go, then as soon as I pass the next treenode, the TTreeView goes into "accept" mode and the node can be dropped. 

Here's the code necessary to reproduce it.  Drop a TTreeView and a TDropFileSource on a form, and set the TTreeView's dragmode to dmAutomatic.  I'm using Delphi 7 if that matters.

procedure TForm1.TreeView1DragOver(Sender, Source: TObject; X, Y: Integer; State: TDragState; var Accept: Boolean);
begin
  Accept := True;
end;
 
procedure TForm1.TreeView1DragDrop(Sender, Source: TObject; X, Y: Integer);
begin
  TTreeView(Source).Selected.MoveTo( TTreeView(Sender).GetNodeAt(X,Y), naAddChild );
end;
 
procedure TForm1.TreeView1MouseDown(Sender: TObject; Button: TMouseButton; Shift: TShiftState; X, Y: Integer);
begin
  DropFileSource1.Execute;
end;

Thanks!

Hi,
I am using the OutlookTarget to drag and drop Emails into my Application. Everything works OK except that the filenames of the attachments are often shortened or replaced by e.g. 'attachment1'. Is there any way to ensure that the attachment name is displyed correctly ?
Thanks for your help
Marcus

Thanks for the greats components …
but the target drop .. (with example TargetDemo ..  not work with Windows Seven 64 bit….)(not accept drop …) 
Thanks for your help

Dear Author,

I would like to drag and drop between a VirtualTreeview and a CADImportVCL component. Is it possible at all? All i want to do is grab nodes from the tree and 'put them' on a cad drawing. I would use only the mouse X,Y coordinates on a mouseUp event… so there would be no any 'classic' d&d data transfering.
What components could i use from your suite for the task above? If i need to use any for this task at all…

Thank you for your help!

I am using your components to get emails from outlook and to read the emails.  It works great for Text and Rich Text emails but if I try to drag over an HTML email I can't seem to get the Body from the message.  I'm using HrGetOneProp(AMessage, PR_BODY, Prop) should I be using something different?

Hey Anders!

I am trying to use the TDropText components with my TSynEdit (I guess you have heard of it?)

I am trying to accomplish a Text-Drop from a component to the TSynEdit. The problem is, while dragging, I wish to set the Caret position of the SynEdit, and that is only possible through the SynEdit's OnMouseCursor event. But that event is not being fired while dragging. How do I work around that? Thank you!

Hi.
I want to drag and drop file from WinExplorer into my app which is a MDI app. I want to drag&drop both in the main and child form.
If I move the mouse over the main form and drop the file, it works.
If I move the mouse over the child form and drop the file, it works.
The problem when I move the mouse first over the child form (and don’t drop yet), then I move the mouse over the main form and want to drop. In this case the cursor shape never changes to the + sign that shows that I can drop the files. And of course the drop operation is not performed.
To fix it, I have to move the mouse back over Win Explorer and then back over my app this time being careful not to go over child form again.
Any hints?

The code is something like this:

{ Using TDropFileTarget and TDropFileSource }
 
procedure TMainForm.DropFileTargetDrop(Sender: TObject; ShiftState: TShiftState; Point: TPoint; var Effect: Integer);
begin
 { Drag to child form }
 if (TCustomDropTarget(Sender).Target is TDirectoryListBox)
 then ChildForm.AddItem(DropFileTarget.Files[0]);
 else
 
 { Drag to MainForm }
 if (TCustomDropTarget(Sender).Target is TMainForm)
 then MainForm.AddItem(DropFileTarget.Files[0]);
 
 if (Effect = DROPEFFECT_MOVE)
 then Effect := DROPEFFECT_NONE;
end;

PS: great component!

I have tried to move the controls from the MDI child form (where the were originally placed) into the parent form, but I get the same result.

Maybe there is a special way to handle MDI applications?

Are you aware of any problems with the drop source components when used under Windows 7?
When using the Version 5.2 SimpleTargetDemo on Windows XP, it compiles and runs (Delphi 7) fine. When the same program is compiled and run under Windows 7 (also Delpihi 7), it refuses to accept anything dropped. Oddly enough, the version compiled under Windows XP will accept dropped files even when run under Windows 7.
Dan

Happy new year Anders

I just noticed that when right clicking a lnk-file my custom context-menu for "AllFileSystemObjects" appears twice. Once for the lnk-file itself and once for the file it links too.

In "DragDropContext.pas" at the beginning of the function TDropContextMenu.QueryContextMenu before the line if (Assigned(FOnPrepareMenu)) then I added the following code to work-around the problem:

// To avoid context-menuitems appearing twice on lnk-files
if not (uFlags and CMF_VERBSONLY = 0) then
begin
  Result := MakeResult(SEVERITY_SUCCESS, FACILITY_NULL, 0);
  exit;
end;

I guess this might break some applications or functionality but it works for my purpose.
Maybe a better solution is to make the uFlags a parameter to the FOnPrepareMenu event, or to make the added code optional through a boolean property?

There's of course also the possibility that it can be done with your original code and I just haven't figured out how to do it.

Happy coding
Per

I get an 'Unspecified Error' when this line of code executes

OleCheck(MAPIInitialize(@MapiInit));

I believe this is initializing the connection to outllook.  My question is, are these libraries compatible with windows terminal server 2008, Outlook 2010?

When I run the emailexample.exe I get a windows error as well

John

Thanks for the quick reply Anders. I've tried your suggestion and managed to find some problems with it though.

Let's say I have selected three files with different extensions, for example a ".pas", a ".dfm" and a ".lnk". Then my contextmenu is only displayed if I rightclick the lnk-file. If I rightclick any of the other files in the selection no contextmenu is displayed. Per-haps not a very likely situation but it could be confusing.

If I rightclick a lnk-file it also seems like using your code will put the name of the linked file in the Files[0] property of the TDropContextMenu instead of the name of the lnk-file itself. In the rare cases I rightclick a lnk-file to use it with this particular extension I'd like it to operate on the lnk-file and not the file it links to. Correct me if I'm wrong and please ask if you didn't understand what I just wrote, I hardly do it myself.
A third and minor thing is that if I ever decide to write more shellextensions for "AllFileSystemObjects" I would have to add code to the OnPrepareMenu event for them too, instead of having the component handle the situation automatically.
Thank you for a fantastic component suite.
Per

It works good on WinXP, but seems not work on Win7, why?

Hi Anders

Lots of thanks for the excellent components you provide.
Following your SourceDemo example, I'm using the TDropFileSource to drop files in other applications.
It seems, however, that some apps (like Skype) do not accept them whilst others (like Word) accept them as filenames instead of opening them.

Best regards
Manos

Nice components, thanks.
I have a question though.   I have a listview control that displays files.  The form that shows this listview can be open multiple times (MDI).  If I do not use your components, put drag mode to automatic - I can successfully move files from one listview to another (across forms).  This is accomplished because the DragDrop event populates a 'source' parameter that I can cast as TListView.  Works great.

I need to add the ability to drag files in and out of these list views to other windows apps/explorer/etc.  If I sent drag mode of the listview to manual, setup droptarget and drop source - I can get that working perfectly.

The problem is now I cannot drag between MDI windows in the app.  If I do not set dragmode to manual - everything is crazy, since I start the drag using your product.  Since dragmode is manual now, I never get the normal dragdrop event.   Using your drop event, I cannot determine the 'source' that it came from - I need access to that listview (and the data it has) to perform the move.  

How can I do both?

Anders,   Thanks for the reply.   I will try the global variable route.  However, in the DropSource OnDrop event, I actually CREATE the files because the user may have dropped them out of the program - then they are copied from the created location to where they dropped them.   If they drop on my own program - I do not need to create these files - as I can just move some pointers around…..the problem is the dropsource ondrop event will fire before my DropTarget event - right?   Therefore I do not know if the DropSource should do anything….when DropSource onDrop is called, I really need to know if the 'target' is my app or not - anyway to do that?Thanks again for the components and the reply!

Hi,

Is the Drag and Drop Component Suite 5.2 compatible with Delphi XE (2011)?

Kind regards,
Guus

Hi Anders
Nice component and it is obvious that you have put a lot of work into it.

I've spent many hours trying to get it to work in my application (managing files on a PVR) and I'm almost there now. My current problem is that the OnLeave event does not always fire when the mouse leaves the DropFileTarget "quickly" - it only gets fired when the mouse is moved slowly from the target (I know that OnLeave is not being called because the event writes a message to a RichEdit control).

As extracting files from the PVR can take a "long" time, I only want to do that when dropping externally from the application (a bit like your ExtractDemo) - internal drags and drops can be performed directly on the PVR.
To determine whether or not I am dropping in the application, I am setting a flag, FInternalDrop, to true when initiating a drag and/or in the OnEnter event and to false in the OnLeave event. The OnGetData event only extracts the files from the PVR when FInternalDrop is false.

Is the lack of a consistent OnLeave event a feature of windows or something wrong in the drag suite (5.2)?

Can you suggest any other mechanism for how I can determine if I am dropping external to the application ? (I don't need to know the target application; setting the flag in the OnDrop event is too late as OnGetData has already fired).

Regards
Geoff

Application details:  XP Pro, Delphi 7.1.
DropFileTarget1.MultiTarget is true ; one target is a treeview and the other is a listview (like explorer). Under the listview is a panel containing a RichEdit control. Dragging quickly from the ListView to the RichEdit control does not always fire the OnLeave event but it does fire if dragged slowly. Have also noticed not always fired when dragging from the listview to the treeview.

I suppose there may be a similar issue with the OnEnter event !

Anders,

RTF and HTML for TDropComboTarget?

Thank you for your components. I find the RtfTarget demo interesting, the possibility to receive data, which the component does not provide as properties, rtf text in this case. For html text I have done a demo to receive html from TDropURLTarget. But is it possible to do the same for TDropComboTarget? I would like to have rtf and html out of TDropComboTarget. Changing the component source would achive this, but is it possible to do this from the application side?

I use D7.

Very nice component pack.

I haven't been developing in Delphi 7 for several years but are now part of a project that step by step translates a very large app from Delphi to WPF. This is done by porting individual components and re-hosting them in Delphi via interop.

Using the drag drop package to elevate the events to COM level works great.

However, I have a minor things, that might spawn a small new feature.

When I drag an item from Delphi to the WPF component it expects the data to be of a specific format (actually, the dataformat tag to be set to a specific string) but the data itself is just generic text (xml).

So this means that I could be using the text component but then I have to add handling to the WPF component to allow an open 'text' data tag and for one reason or another the creators of that component would like to keep the id'ing tag as it is.

So the drag component needs to id the content correctly. Now, I guess that means I have to either create a sibling component to the text-one, or learn how to use the dataformatter — but for me it would be cool if the text component just had the option to have the set data tags to be overwritten or another component that accepts text etc but with a custom data tag.

Maybe I am making this too complicated for me… what is the recommended approach? It is a minor thing but I am not sure about the best solution path.

Hi Anders
Many thanks for your reply and apologies for the time I have taken to respond (difficulties loading Indy10 and I wanted to try your suggestions first).

First, my OnEnter and OnLeave now seem to be working ok (I used your method of changing the background colour to prove it; I still don't see why the display of my message didn't work as I am only using synchronous operations). So please accept my apologies for making you go through your code.

Prior to your response, I did get my program working as I wanted using DropFileSource and DropFileTarget. The only problem was that the cursor would stall over the windows explorer task bar icon as the files were created (one would need to keep the mouse down a long time for large transfers!).
After much trial and error, I have now managed to get the program to work using TVirtualFileStreamDataFormat (as in "AsyncSource with FileStreams" but synchronously) and this eliminates the stall. I thought I had then encountered an intractable problem in that while this works fine for files, I couldn't see anyway of copying empty folders. However, I've just found that by setting faDirectory in the file attributes, setting FD_ATTRIBUTES in dwflags, and returning nil as the stream in OnGetStream, I can create empty folders in explorer. This allows me to mix files and folders in the same drag operation.
Whether or not this works on versions of Windows after XP remains to be seen!

Many many thanks
Geoff

I need to allow drag&drop between my 2 application (from TDBGrid in application A to TEdit in application B).
How can I do it? Thank you for answer.

Hello, I try to use your components to perform a drag and drop of the attached files from Outlook (V12/2007) in my delphi application but I can not.
Is what you could give me the solution?
Thank you.

Hello,
I use your great component with Delphi XE under Windows Server 2008 R2. Unfortunately, the drag/drop events do not occur. I tested some demo application but they do not react as expected either.
Any hints?

Thanks!

Be,
Jürgen Bauer

Anders, first congratulations that you started developing your components again! I was really sad when I saw that your site was down a few years ago, and that you stopped working on it. But a few months ago I accidentally went here and, boy, was I happy!

I have a small suggestion: I used the HTML property of the Combo component in the past, but it is now gone. I learned how to use the separate HTMLClipboardFormat class and it is working excellent, but there is a small issue with it. It uses the new Unicode TStrings class, however Firefox uses UTF8 texts. It is not a problem to do a conversion between them when I am using single character Windows code page (like Latin, Cyrillic and so on), but if Windows uses for example Chinese coding page, then the HTML gets messed up.

Currently, I worked around it by adding an UTF8String property to the THTMLClipboardFormat and it works perfect. But generally, I don't want to mess with other people components, because it is a maintenance nightmare, so is there a chance that you add such properly in the next version officially?

Since THTMLClipboardFormat uses UTF-8 strings anyway, I think it will be reasonable to use it in the component too.

Hello,
I drop a message from Outlook2000 to OutlookDemo. When program wants to read this message  i've a AV on this line in funtion ViewMessage

Value := String(Rows.aRow[i].lpProps[j].Value.lpszA);

I am under Windows XP and Delphi2009
Someone knows what is wong ?
Thanks for your help.

Is it compatible with Outlook 2010 64bit? I get an error when I run the Outlook demo "either there is no default mail client or …"Thanks

Please advise me with Delphi XE and Drag'n'Drop suite. I compile, run "SourceDemo" project (DragDrop\Demos\SourceDemo\) and try to move file from list to the root of D:\, but mouse shows me that I can't do it (mouse icon shows that I can't do it). If I start some application which accept files (MS Word for example), it accepts file withour problems.Please advise me what can it be? If I compile the same demo in Delphi 2010, this demo works correctly.
My OS is Win7 x86 SP1 Professional.

Hi,

Is possible change default system image (not cursor) when you drag file?
For example when you drag JPEG, system is using image preview insted .jpg icon.
I created custom image format and want to use dragged image thumbnail insted it icon (shell thumbnail handler not created, because I don't know how ;().

And second: after drag, in some cases I dispaly messagebox(), how to erase system image (see above)?

Hello Anders,

First, thanks for making such a great component! I don’t know what I’d do without it.

Second, I’ve ran into a problem which might be a memory leak in your component. I’m using a DropFileTarget with a DataFormatAdapter set to TVirtualFileStreamDataFormat format to be able to accept files from Outlook2007/2010. I’m saving it in a database with the following code:

Stream := TVirtualFileStreamDataFormat(DataFormatAdapter.DataFormat).FileContentsClipboardFormat.GetStream(I);
if (Stream <> nil) then
begin
  OleStream := TOleStream.Create(Stream);
  try
     DBQuery.ParamByName('blob').LoadFromStream(OleStream, ftBlob);
  finally
    OleStream.Free;
  end;
end;

I’m using Eurekalog for memory leak detection and it threw up the following leak:

Leak type = TOleStream (Total size = 8 )
Unit / Class / Procedure/method / Line no.
DragDropFormat.pas TCustomSimpleClipBoardFormat DoSetData 1278[81]
DragDrop.pas TClipboardFormat SetDataToMedium 1141[11]
DragDrop.pas TClipboardFormat SetData 1148 [2]
DropTarget.pas TCustomDropTarget SetPerformedDropEffect 1474[4]

Leak type = TFixedStreamAdapter (Total size = 32)
Unit / Class / Procedure/method / Line no.
DragDropFormat.pas TCustomSimpleClipBoardFormat DoSetData 1279[82]
DragDrop.pas TClipboardFormat SetDataToMedium 1141[11]
DragDrop.pas TClipboardFormat SetData 1148[2]

There is a comment in the code at the lines in question, but I don’t know if it’s related.

Could you please look into this if you have the time?

Thanks!

Hello Anders,

Firstly, thank you for publishing such an excellent package.

The project I am working on is to implement the shell DropTarget functionality as a replacement to the deprecated ddeexec functionality for opening files from explorer. The objective is for explorer to be able to open multiple files in a single instance of my application - for this, I have to use either ddeexec or DropTarget registry entries.

I have your TDropFilesTarget working nicely. In fact, to strip away any possible problems, I am just using your Simple Target Demo, which I have registered in the windows registry and have associated with a test file type with extension '.xyz'. With the Simple Target Demo running, dragging files onto the application works fine. However, with the Simple Target Demo not running, double clicking a .xyz file does launch the application, but the double-clicked file is not 'dropped' into the application. I see that the Simple Target Demo is launched by explorer with the '-embedding' parameter, so I believe I have configured the registry correctly. But explorer hangs for several seconds. I am guessing that explorer is waiting for the application to register in some way, so that it can then drop in the file. However the registration that makes the drop functionality work with a real drop done with the mouse, does not seem to be sufficient or equivalent for files dropped programmatically by explorer.

Am I doing something fundamentally wrong? Any suggestions are welcome.

Many thanks

Steve

P.S. The documentation I have used is here:
http://msdn.microsoft.com/en-us/library/ms683844(VS.85).aspx
http://msdn.microsoft.com/en-us/library/ee872121(VS.85).aspx

Hello Anders
Firstly thank you for publishing this excellent package.
I have been tasked with the project of integrating drag and drop from Outlook and Thunderbird into an application. I have worked with your Outlook example and managed to use and change the code sufficiently for my drag and drop from Oulook but I am getting unstick with trying to drag and drop from Thunderbird. I am using the Tdataformatadapter with the Outlookdataformat but was hoping to trap the drop if it was coming from something else e.g. Thunderbird. Unfortunately I have had no luck. Can you provide an example or some direction on how I could trap drag and drop items from different email clients and then decide what to do from the result.

Many Thanks
Alan

In window 7, admin mode…Drag and drop does not support.
Please test SimpleTargetDemo on admin mode.

Dear Anders,
First.. Thank you for your execllent suite.
I found bug conern admin privilage on window 7.
When you test another computer which does not installed delphi and execute by admin privilage.
Drag and drop from file explore to application does not support.
Ofcause non admin privilage execute work file.
Please check that bug
I hope this problem can fix as soon as possible.

Best regards
Tommy Lee.