Drag and Drop Component Suite + Drop to Outlook not working

[microtronx 38]

Hi, on my side i can drop from delphi app with this component to desktop without problems but drop to a new message window in outlook is not working. It shows the [+] sign when moving the mouse on that new message form but dropping does nothing

 

See: https://github.com/DelphiPraxis/The-Drag-and-Drop-Component-Suite-for-Delphi/issues/38

 

Anyone having same issues or a solution?

[Anders Melander 1780]

What data types (text, filenames, bitmap etc) are you dragging?

 

Edit: Never mind. I see from the ticket that you're dragging files.

Edited September 13, 2019 by Anders Melander

[Anders Melander 1780]

Try diagnosing the problem with the attached utility:

Drag from the Drop Source pane and drop onto Outlook. You should be able to see what data Outlook asks for.

If you compare the sequence when dropping on a 32-bit Outlook to that of a 64-bit, then maybe it becomes clear what's going on.

DragDropTracer.zip

[microtronx 38]

 Here's my Outlook 2019 in 64bit, can someone test this with new Outlook in 32bit so we can compare:

 

TDropFileSource,Execute,>>>
TDropFileSource,OnGetDragImage,
TDropFileSource,OnGetData,Shell IDList Array
TDropFileSource,OnGetData,IsShowingText
TDropFileSource,OnGetData,UsingDefaultDragImage
TDropFileSource,OnGetData,DragSourceHelperFlags
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnGetData,DragContext
TDropFileSource,OnGetData,Shell IDList Array
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,Shell IDList Array
TDropFileSource,OnGetData,IsShowingText
TDropFileSource,OnGetData,UsingDefaultDragImage
TDropFileSource,OnGetData,DragSourceHelperFlags
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnGetData,DragContext
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,Shell IDList Array
TDropFileSource,OnGetData,Shell IDList Array
TDropFileSource,OnGetData,Preferred DropEffect
TDropFileSource,OnGetData,Shell IDList Array
TDropFileSource,OnGetData,DropEffectFolderList
TDropFileSource,OnGetData,Preferred DropEffect
TDropFileSource,OnGetData,Shell IDList Array
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,
TDropFileSource,OnGetData,UntrustedDragDrop
TDropFileSource,OnGetData,DisableDragText
TDropFileSource,OnGetData,IsComputingImage
TDropFileSource,OnGetData,DropDescription
TDropFileSource,OnFeedback,19
TDropFileSource,OnDrop,
TDropFileSource,OnGetData,Object Descriptor
TDropFileSource,OnGetData,FileName
TDropFileSource,OnGetData,CF_HDROP
TDropFileSource,OnAfterDrop,
TDropFileSource,Execute,<<<

 

Edited September 16, 2019 by microtronx
gramar

[Anders Melander 1780]

I just realized that I've already released a newer version of the tracer. It's in the Demos folder:

https://github.com/DelphiPraxis/The-Drag-and-Drop-Component-Suite-for-Delphi/tree/master/Demos/TargetAnalyzer

It lacks the ability to save the trace though.

 

Everything appears fine judging from the trace; The drop targets (I'm assuming you dragged across some other drop targets before you dropped on Outlook) queries for various formats during the drag and after the drop the target (Outlook) asks for the "Filename" and CF_HDROP formats.

 

My guess was initially that there either something wrong with the particular file you're dragging which caused Outlook to reject it or that the data returned by the drop source was corrupted somehow (you could use the SourceAnalyzer demo to check the data). But then I found this:

 

Drag & Drop files from 32bit winforms application to 64bit Outlook

 

TLDR; It appears to be a known problem in Windows which apparently hasn't been fixed yet.

According to one of the comments a possible solution is to use the FileContents and FileGroupDescriptor formats instead.
See the VirtualFile, VirtualFileStream, SyncSource and AsyncSource with Filestreams demos for examples of how to do that. AFAIR you can add these formats to your existing drop source with an Adapter, but I can't remember how to do that. There's probably a demo about it.

 

Here's another thread about the problem but here they don't seem to have realized it's a 32/64 bit issue:

Issue with file drag/drop to Outlook in Windows 10

[microtronx 38]

Thank you very much Anders,

 

i will try to work with FileContents and FileGroupDescriptor if possible. But it must be possible to drag&drop to desktop or any other target.

We have 99.99% only files which are saved to a temporary folder and added to dropsource.

 

If we get it work, we will post it here.

[Anders Melander 1780]

Explorer (e.g. the desktop) supports FileContents/FileGroupDescriptor and many other application does as well.

 

If your files are mostly virtual (i.e. they are generated from a database or the like) and are only saved to disk in order to be able to drag them, then FileContents/FileGroupDescriptor is actually the right choice. In that case make FileContents/FileGroupDescriptor your primary format and only write the data to disk if the drop target requests CF_HDROP/Filename.

[microtronx 38]

Changed to tDropEmptySource with tDataFormatAdapter set to TVirtualFileStreamDataFormat and now it looks like it works ...

 

+Anders: Thanks a lot for you tip!