How to Use Drag and Drop

[newbieg]

Hi I was wondering how to implement Drag and Drop.

Basically I have a bunch of graphics files that I need to change the background colors to transparent. I could do this in code but I'd have to type in each image address by hand and the graphics are in multiple files, I figure using drag and drop would be much quicker and I could use it in later programming too.

I'm using visual C++ 2010 (Free Version), I have SFML up and running. OS = windows7
Is there an SDK that I'd have to download to do this?

[o3hC5Di1]

I'm sorry, I'm afraid I don't quite follow how you would like to use drag and drop here?

Might thisbe what you are looking for? : http://codebetter.com/petervanooijen/2007/07/07/basic-drag-and-drop-in-winforms/

All the best,
NwN

[newbieg]

I want to be able to drag an image file from a folder or the desktop to my program and be able to get the address of that file into the program so the program can make a copy of the file after changing the background colors.

[modoran]

Just process WM_DROPFILES in your window procedure. There is example code already posted in these forums.

case WM_DROPFILES:
		{
	
		TCHAR lpszFile[MAX_PATH] = {0};
		UINT uFile = 0;
		HDROP hDrop = (HDROP)wParam;

		uFile = DragQueryFile(hDrop, 0xFFFFFFFF, NULL, NULL);
		if (uFile != 1){
			MessageBox (hDlg, _T("Dropping multiple files is not supported."), NULL, MB_ICONERROR);
			DragFinish(hDrop);
			break;
			}
		lpszFile[0] = '\0';
		if (DragQueryFile(hDrop, 0, lpszFile, MAX_PATH))
			{
				MessageBox (NULL, lpszFile, NULL, MB_ICONINFORMATION);
			}
			
		DragFinish(hDrop);
			break;
		}

[newbieg]

OK, uh, I have no Idea what is going on in that code, is there a link to a tutorial, or to the original example code?

I don't know what it means to "process WM_DROPFILES in your window procedure" especially since I don't know about "window procedure" in the first place.

Thanks for the help, but I'm just not at that level yet. Any links you have would be very helpful.

[o3hC5Di1]

Hi there,

Code seems to come from this thread:
http://www.cplusplus.com/forum/windows/59537/2/

Here's an article giving some more explanation, not sure if it will be enough to you though:
http://bcbjournal.org/articles/vol1/9709/What_a_drag!.htm?PHPSESSID=5bbb31e23a30aca64ebc297392a4286a

All the best,
NwN