如何检查外部WPF进程或其他进程是否已启动？

Question

I've written a WPF/C#-based "shell" which launches WPF apps or other apps.

What would be the best method for checking if the process is finally fully launched or no longer "busy"? I've noticed that the mouse cursor for the launched process stays at the busy cursor from initial launch until I can finally see the UI for the process. Could I use User32.SetCapture API to set the mouse capture to the external process, then somehow check if the mouse cursor is the busy cursor? Or perhaps there's a mechanism in the System.Diagnostics.Process class that I'm unaware of?

As some of the launched apps are pre-compiled third-party apps, I absolutely cannot implement a mechanism in the external processes to message if it is finally ready, such as: Microsoft PowerPoint 2010 Viewer, Adobe Acrobat, or Adobe Flash Player Standalone.

I can't just check if the process has been created, because then I have a blank, unresponding window and a busy cursor. I hope to hide my WPF app the moment the external process is done launching.

Answer 1

The WaitForInputIdle Win32 APi function will wait until given process enters the message loop (with no input pending).

Quote: "Before trying to communicate with the child process, the parent process can use the WaitForInputIdle function to determine when the child's initialization has been completed."

You can call it via P/Invoke.

Answer 2

Not very cear what do you mean saying "beasy", but hear are several considerations:

There is no known (clear) way, at least that I'm aware of, that can let you do something like that. The thing is that process is perfectly isolated OS kernel citizen. So you can not write something that works for all type processes, especially if they are 3rd part binaries.

What you can try to do, is get the MainWindow of the process (if there is any), get its handle , and filter OS messages untill you get for example WM_ACTIVATED .

But even if this could work in certain situations, in others can measurably fail. For example, process loaded but the program is not active, cause for some reason License window of the application appeared.

Let's see what others suggest, in my opinion, there is no generic and no single solution to cover minority of possible cases.

Good luck