Windows Desktop ListView Handle

I have been using a utility function in my TaskbarExt application for years to get the current Desktop ListView window handle (SysListView32 to be exact) to show/hide the icons depending on user preferences.

This has worked well for years, but recently I enabled the Windows Desktop wallpaper rotation, and I noticed that this function randomly stops working. On debugging the issue, I found that when the wallpaper rotation is enabled, instead of loading the “SHELLDLL_DefView” window in the “Progman”, Windows was loading under the “WorkerW” window. BTW, the Spy++ Tool was great help in debugging all this.

Once I know what’s going on, the fix was quite easy. In case your are running into similar issues, here is the sample code which works for me:

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HWND GetDesktopListViewHWND()
{
  HWND hDesktopListView = NULL;
  HWND hWorkerW = NULL;
 
  HWND hProgman = FindWindow(_T("Progman"), 0);
  HWND hDesktopWnd = GetDesktopWindow();
 
  // If the main Program Manager window is found
  if (hProgman)
  {
	// Get and load the main List view window containing the icons (found using Spy++).
    HWND hShellViewWin = FindWindowEx(hProgman, 0, _T("SHELLDLL_DefView"), 0);
    if (hShellViewWin)
      hDesktopListView = FindWindowEx(hShellViewWin, 0, _T("SysListView32"), 0);
	else
		// When this fails (happens in Windows-7 when picture rotation is turned ON), then look for the WorkerW windows list to get the
		// correct desktop list handle.
		// As there can be multiple WorkerW windows, so iterate through all to get the correct one
		do
		{
			hWorkerW = FindWindowEx( hDesktopWnd, hWorkerW, _T("WorkerW"), NULL );
			hShellViewWin = FindWindowEx(hWorkerW, 0, _T("SHELLDLL_DefView"), 0);
		} while (hShellViewWin == NULL && hWorkerW != NULL);
 
		// Get the ListView control
		hDesktopListView = FindWindowEx(hShellViewWin, 0, _T("SysListView32"), 0);
  }
 
  return hDesktopListView;
}

Hopefully the comments should explain what’s going on very well. But if you still have any questions or suggestions, please do share with me.

On a side note, any wallpaper with icons turned off looks so beautiful. So I would recommend give this a try. So, if you are a programmer, which you most probably are if are reading so far, then better go ahead and implement this yourself. It will be a nice little utility. If however, busy with some other stuff, you can try my TaskbarExt application and get this in action quickly.

Tags: Desktop, Handle, Win32 API, Window

This entry was posted on Saturday, January 19th, 2013 at 2:39 pm and is filed under Visual C++, Win32 API. You can follow any responses to this entry through the RSS 2.0 feed.
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