Chris Johnsson Chris Johnsson - 1 month ago 11
C# Question

Connecting windows/frames hosted by ‚ApplicationFrameHost‘ to their real processes

I am working on an WPF application to monitor my activities on my computer. I use

Process.GetProcesses()
and some filtering to get the processes I am interested in (example:Calculator) then I record their StartTime. I am also using WIN32/USER32 API method
GetForegroundWindow()
to get the window the user is using.

The problem is that when the windows are Windows/UWP applications they are always hosted by the process ApplicationFrameHost. So the
GetForegroundWindow()
method returns that window with a title (example:Calculator), but not the real process being hosted.

What I need is either another way to get the foreground window that includes the real process being hosted, or some way to connect the window to process.

Anyone that knows how to accomplish this? All help would be really appreciated.

Answer

I eventually found a way to do this, so I am going answer my own question so maybe someone in the future with the same problem could find it useful.

This is the class with the WinApiFunctions:

public class WinAPIFunctions
{
    //Used to get Handle for Foreground Window
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    private static extern IntPtr GetForegroundWindow();

    //Used to get ID of any Window
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    private static extern int GetWindowThreadProcessId(IntPtr hWnd, out int lpdwProcessId);
    public delegate bool WindowEnumProc(IntPtr hwnd, IntPtr lparam);

    [DllImport("user32.dll")]
    [return: MarshalAs(UnmanagedType.Bool)]
    public static extern bool EnumChildWindows(IntPtr hwnd, WindowEnumProc callback, IntPtr lParam);

    public static int GetWindowProcessId(IntPtr hwnd)
    {
        int pid;
        GetWindowThreadProcessId(hwnd, out pid);
        return pid;
    }

    public static IntPtr GetforegroundWindow()
    {
        return GetForegroundWindow();
    }
}

And this is the class I used to test if it would work. I used it in a simple console program that just writes out the name of the process that has current focus:

class FindHostedProcess
{
    public Timer MyTimer { get; set; }
    private Process _realProcess;
    public FindHostedProcess()
    {
        MyTimer = new Timer(TimerCallback, null, 0, 1000);
        Console.ReadKey();
    }

    private void TimerCallback(object state)
    {
        var foregroundProcess = Process.GetProcessById(WinAPIFunctions.GetWindowProcessId(WinAPIFunctions.GetforegroundWindow()));
        if (foregroundProcess.ProcessName == "ApplicationFrameHost")
        {
            foregroundProcess = GetRealProcess(foregroundProcess);
        }
        Console.WriteLine(foregroundProcess.ProcessName);
    }

    private Process GetRealProcess(Process foregroundProcess)
    {
        WinAPIFunctions.EnumChildWindows(foregroundProcess.MainWindowHandle, ChildWindowCallback, IntPtr.Zero);
        return _realProcess;
    }

    private bool ChildWindowCallback(IntPtr hwnd, IntPtr lparam)
    {
        var process = Process.GetProcessById(WinAPIFunctions.GetWindowProcessId(hwnd));
        if (process.ProcessName != "ApplicationFrameHost")
        {
            _realProcess = process;
        }
        return true;
    }
}
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