Windows drag & drop with win32com and IDropTarget

[Tim Golden]

On 15/01/2010 07:20, Greg K wrote:
> I'm trying to create a program that will process files dragged into
> its window, however I can't seem to get the cursor to change correctly
> when something is dragged over the window. I've created an object that
> implements the IDropTarget interface, but it seems the value returned
> by its DragEnter method is ignored by Windows. No matter what value it
> returns, I always get a "create shortcut" cursor when something is
> dragged over the window.

This is a segment of my code which works ok:

<... code snippet ...>
   def DragEnter (self, data_object, key_state, point, effect):
     ur"""Query the data block for a drag action which is over the dialog.
     If we can handle it, indicate that we're ready to accept a drop from
     this data.
     """
     try:
       data_object.QueryGetData (self._data_format)
     except pywintypes.error:
       return shellcon.DROPEFFECT_NONE
     else:
       return shellcon.DROPEFFECT_COPY
<... code snippet ...>

The whole code's here if you want:

https://winsys.googlecode.com/svn/trunk/winsys/dialogs.py

It looks as though you're returning an OK *and* the effect
which isn't how the thing is implemented via the pywin32
wrappers.

TJG