Catch WM_DROPFILES in TRichEdit

[Chelly 0]

Hi, I upgraded the builder from XE6 to 12.

How can I catch the WM_DROPFILES message when I drag an image file (like PNG or JPG) and drop it into a TRichEdit? Other types of files are correctly catching the WM_DROPFILES, but image files don't work.

It seems like the image file is automatically converted to RTF text. How can I stop this behavior?

[Remy Lebeau 1458]

Are you subclassing the RichEdit to receive WM_DROPFILES? Are you registering the RichEdit with DragAcceptFiles() to receive WM_DROPFILES?

 

Unlike other UI controls, a RichEdit can send an EN_DROPFILES notification to its parent window when you drop files onto the RichEdit. Are you able to receive that notification?

[Chelly 0]

40 minutes ago, Remy Lebeau said:

Are you subclassing the RichEdit to receive WM_DROPFILES? Are you registering the RichEdit with DragAcceptFiles() to receive WM_DROPFILES?

 

Unlike other UI controls, a RichEdit can send an EN_DROPFILES notification to its parent window when you drop files onto the RichEdit. Are you able to receive that notification?

Thank you for your answer.
I have used DragAcceptFiles() and set the parent window to receive the notification, but it still can't handle the WM_DROPFILES message.
Only image files are not accepted.

By the way, the same code works correctly in XE6.
 

[PeterBelow 240]

XE6 and D12 use different versions of the Windows richedit control as far as I remember, that may explain the change in behaviour you see.

[Chelly 0]

12 hours ago, PeterBelow said:

XE6 and D12 use different versions of the Windows richedit control as far as I remember, that may explain the change in behaviour you see.

Yes, the version of RichEdit in 12 is 4.1, starting from 11. However, I couldn't find any update logs about image drag-and-drop behavior on the Microsoft website.

[PeterBelow 240]

Well, it has to be something you do in your code then. I just created a new VCL app (D12.2), dropped a TRichedit on it, build and ran and it inserts an image (jpg in this  case) dragged from Explorer to it just fine. If you now handle WM_DROPFILES or such try to disable that.

[Remy Lebeau 1458]

6 hours ago, PeterBelow said:

Well, it has to be something you do in your code then. I just created a new VCL app (D12.2), dropped a TRichedit on it, build and ran and it inserts an image (jpg in this  case) dragged from Explorer to it just fine. If you now handle WM_DROPFILES or such try to disable that.

Read the OP's opening message again more carefully. They want to handle WM_DROPFILES manually and disable the default behavior for inserting dropped image files.

Edited January 10 by Remy Lebeau