Restore a minimized window of another application (C++ WinAPI)

Question

I'm working on a C++ program that which launches a .NET Winforms application.

If the app is already running, I want to restore the window instead. I grab the .NET app's window handle and use SetForegroundWindow() to bring to to the front.

This works except when the application is minimized.

I've tried combinations of the following:

ShowWindow(windowHandle, SW_SHOW);
ShowWindow(windowHandle, SW_RESTORE);

and

SendMessage(windowHandle, WM_SYSCOMMAND, SC_RESTORE, 0);        

However, when this code is executed, the event becomes stuck. In the tray I see ".NET-BroadcastEventWindow.2.0.0.0.378734a.0" come up as a second window in the tray along with my .NET app, and the app is never restored properly.

This only happens when I try to send a SW/SC_RESTORE or SHOW event. SetForegroundWindow() has no issues.

Has anyone else seen this problem before?

Answer 1

I've had similar problems in the past that I've solved using Get/SetWindowPlacement():

// Ensure that the given window is not minimized.
// If it is minimized, restore it to its normal state.
void EnsureNotMinimized(HWND hWnd)
{
   WINDOWPLACEMENT placement;
   placement.length = sizeof(placement);

   if(!GetWindowPlacement(hWnd, &placement))
      return;

   BOOL minimized = (placement.showCmd & SW_SHOWMINIMIZED) != 0;
   if(!minimized)
      return;

   placement.showCmd = SW_SHOWNORMAL;
   SetWindowPlacement(hWnd, &placement);
}

However, I've only used this for windows that belong to my own application. I don't know if security would allow it to be used on outsiders.