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.