How to accept Drag 'n Drop from Outlook Express or any other application besides the Explorer...?

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3 total messages Started by Oren Halvani Wed, 20 Sep 2006 01:15

#3064

Author: Oren Halvani
Date: Wed, 20 Sep 2006 01:15

50 lines
2637 bytes

dear builders,

can someone explain me what i should do if i want my programm to accept Drag 'n Drop
from Outlook Express (for instance: E-Mails or News-posts) or any other application ?

The below function works pretty fine for Drag 'n Drop of files from the Windows Explorer,
but what about other applications ???

Do i need to catch the Drag 'n Drop message of each specific application via:

           BEGIN_MESSAGE_MAP
              MESSAGE_HANDLER(WM_DROPFILES, TWMDropFiles, WMDropFiles);
           END_MESSAGE_MAP(TForm)

I've noticed, Drag 'n Drop of text into my program works from the most applications
that use lke my program the RichEdit control...so why can't I do the same Drag 'n Drop
for other things like: E-Mails from Outlook Express or Thunderbird, etc... ?



Oren

/***********************************************************/
void __fastcall TfrmMainUnit::WMDropFiles(TWMDropFiles &Message)
{
   int DropCount = DragQueryFile((HDROP)Message.Drop, -1, NULL, 0), StrLength;
   char FileName[MAX_PATH];

   for(int index = 0; index < DropCount; index++)
   {
     StrLength = DragQueryFile((HDROP)Message.Drop, index, NULL,0);
     DragQueryFile((HDROP)Message.Drop, index, FileName, StrLength + 1);

     if(FileGetAttr(FileName) & faDirectory) {AddFiles_Check(FileName);}
     else
     {
        FileShow(FileName);
        SaveRegFiles();
        FileBox_Operations();
     }
   }

   if(DropCount > 0)
   {
      FileBox->Selected[-1] = true;
      cmdEditMode->Down     = false;

      if(frmMainUnit->Active && txtContains->Enabled) txtContains->SetFocus();
   }
}

Re: How to accept Drag 'n Drop from Outlook Express or any other application besides the Explorer...?

#3066

Author: Remy Lebeau (TeamB)
Date: Wed, 20 Sep 2006 03:41

38 lines
2511 bytes

"Oren Halvani" <Spam@halvani.de> wrote in message
news:45109658@newsgroups.borland.com...

> can someone explain me what i should do if i want my programm
> to accept Drag 'n Drop from Outlook Express (for instance:
> E-Mails or News-posts) or any other application ?

What you are asking for is VASTLY more complex to implement than what you
were using before.  You have to write a class that inherits from the
IDropTarget interface, and then use RegiserDragDrop() to let the OS know
about it.  When another application wants to begin a Drag&Drop operation, it
has to call DoDragDrop().  When an item is dragged over your application and
then dropped, the variable methods of the IDropTarget interface will be
called inside your application.  You can then retrieve the data from the
provided IDataObject interface.

Please go to http://www.deja.com and search through the newsgroup archives.
This topic has been discussed many times before.

> Do i need to catch the Drag 'n Drop message of each specific application

No, because there are no messages involved to begin with.

> I've noticed, Drag 'n Drop of text into my program works from the
> most applications that use lke my program the RichEdit control...

That kind of Drag&Drop operation is handled by the RichEdit control itself
at the OS layer.

> why can't I do the same Drag 'n Drop for other things like: E-Mails
> from Outlook Express or Thunderbird, etc... ?

Because you are approaching the issue from the wrong direction.  Such data
requires a completely different approach, as described above.


Gambit

Re: How to accept Drag 'n Drop from Outlook Express or any other application besides the Explorer...?

#3069

Author: Oren Halvani
Date: Wed, 20 Sep 2006 21:31

31 lines
2073 bytes

"Remy Lebeau (TeamB)" <no.spam@no.spam.com> schrieb im Newsbeitrag
 news:4510b9e4@newsgroups.borland.com...


> What you are asking for is VASTLY more complex to implement than what you
> were using before.  You have to write a class that inherits from the
> IDropTarget interface, and then use RegiserDragDrop() to let the OS know
> about it.  When another application wants to begin a Drag&Drop operation, it
> has to call DoDragDrop().  When an item is dragged over your application and
> then dropped, the variable methods of the IDropTarget interface will be
> called inside your application.  You can then retrieve the data from the
> provided IDataObject interface.

> No, because there are no messages involved to begin with.
>

>
> Because you are approaching the issue from the wrong direction.  Such data
> requires a completely different approach, as described above.
>
>
> Gambit



thanks Remy, i thought it won't be so complicated...it's a really complex task :-)
anyhow, thanks for the feedback :-)



Oren

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