How to bring window on top of the process created

问题:

I am launching a process from my application using CreateProcess API and I want to bring the window of the new process to top. Is there a way to do it? Do we have any flag or something like that with CreateProcess?

回答1:

You can try to use the STARTUPINFO structure which is passed in with CreateProcess and set SW_SHOW. I'm not sure this will help bring the focus to the top though. If that doesn't work then try the following.

First off, do not use FindWindow(), it is unnecessarily unreliable since it only works via the window name and class name. Instead, from your CreateProcess() call you should read lpProcessInformation and grab the dwProcessId. Then call EnumWindows() and have your callback look something like this:

BOOL CALLBACK EnumWindowsProc( HWND hwnd, LPARAM lParam ) {
  DWORD dwPID;

  GetWindowThreadProcessId( hwnd, &dwPID );

  if( dwPID == lParam ) {
    SetWindowPos( hwnd, HWND_TOP, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE );

    // Or just SetFocus( hwnd );
    return FALSE;
  }

  return TRUE;
}

When calling EnumWindows() you will need to pass in the PID you grabbed earlier as the lParam like so:

EnumWindows( EnumWindowsProc, ( LPARAM )( PI -> dwProcessId ) );

回答2:

You need the window handle of the application you launched. If you don't have it, you could use the FindWindowA API call.

Then use the SetFocus API call with the window handle as parameter.

Related links:

http://www.andreavb.com/tip020001.html
http://msdn.microsoft.com/en-us/library/aa697422%28v=vs.71%29.aspx