ProcessID (kill the process) c# not returning a value

Question

I am trying to cleanly close the Excel,Powerpoint or word process based on the process id.

Workflow: The purpose is we have 2 folders. 1 for each screen. We are working with a dual screen setup and want to display word on 1 page and excel on the other. This works like charm. When 1 of the files gets edited. Or they place another file in 1 of the folders. I ask the program to kill the processes. and reload the files (the new ones) I do this with the watcher event handling.

So i fill a list with all the processID's when the program starts ( Powerpoint/excel/word )

///list of all CREATED processes ( word / excel / powerpoint + adds in the list
public static List<int> pids = new List<int>();
p.Start();
pids.Add(p.Id);

When the Changes happen. I launch a method that checks if the processes in the Pids list match 1 of the processes in the processes list of all the processes running on the host.

Process[] runningProcs = Process.GetProcesses();

foreach (Process proc in runningProcs) {
  foreach (int pid in pids) {
       if (pid == proc.Id) {
           TryKillProcessByMainWindowHwnd(pid);
           }
   }
}

This works perfectly. As this only returns true when it matches and it passes thru the processid.

I import the DLL through this statement

[DllImport("user32.dll")]
private static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

I recall to this method through here

 public static bool TryKillProcessByMainWindowHwnd(int hWnd) {

        uint processID;

        GetWindowThreadProcessId((IntPtr)hWnd, out processID);

        if (processID == 0) return false;

        try {

            Process.GetProcessById((int)processID).CloseMainWindow();

        }
        catch (ArgumentException) {
            return false;
        }
        catch (Win32Exception) {
            return false;
        }
        catch (NotSupportedException) {
            return false;
        }
        catch (InvalidOperationException) {
            return false;
        }
        return true;
    }
///Watcher event service that checks both subfolders for changes
       public static void watch(string scherm)
    {
        watcher.Path = "C:\\test\\";
        watcher.IncludeSubdirectories = true;
        watcher.NotifyFilter = NotifyFilters.LastWrite;
        watcher.Filter = "*.*";
        watcher.Changed += new FileSystemEventHandler(OnChanged);
        watcher.Created += new FileSystemEventHandler(OnChanged);
        watcher.EnableRaisingEvents = true;
    }

/// Onchanged event handling
public static void OnChanged(object source, FileSystemEventArgs e) {
  watcher.EnableRaisingEvents = false;
///This code first deletes all processes and then tries to clean up the     folder (method explains beneath this topic)
  ReleaseOlderFiles();
///checkfolder launches the new edited files. + screen allocation
  checkFolder();
  Debug.WriteLine("Onchanged fired!");
  watcher.EnableRaisingEvents = true;
}

///ReleaseOlderFilesMethod
      public static void ReleaseOlderFiles()
    {

        string[] files = Directory.GetFiles(scherm1);

        foreach (string file in files)
        {
            FileInfo fi = new FileInfo(file);

            if (fi.LastAccessTime < DateTime.Now.AddMilliseconds(-5000))
            {
                try
                {
                    Process[] runningProcs = Process.GetProcesses();

                    foreach (Process proc in runningProcs)
                    {
                        foreach (int pid in pids)
                        {

                            if (pid == proc.Id)
                            {
                                TryKillProcessByMainWindowHwnd(pid);
                            }
                        }
                    }
                }

                catch { }
                fi.Delete();
            }
}

The hWnd variable is filled every time with the hWnd from either Excel/Powerpoint/Word. For some odd reason the processID always returns a 0 value. So the call to the method does not seem to output anything

I tried it all but what am I not seeing? Thanks in advance, this would be such a major help in the finalization of my project !

Answer 1

Found the solution ! Simple as that ! As @Maksim Simkin said. just change the processID. Like so:

 public static bool TryKillProcessByMainWindowHwnd(int processID)
    {

        try
        {
            Process.GetProcessById((int)processID).CloseMainWindow();
        }
        catch (ArgumentException)
        {
            return false;
        }
        catch (Win32Exception)
        {
            return false;
        }
        catch (NotSupportedException)
        {
            return false;
        }
        catch (InvalidOperationException)
        {
            return false;
        }
        return true;
    }

And in my Method that deletes the file. I needed to add a little sleep towards the thread.

        public static void ReleaseOlderFiles()
    {

        string[] files = Directory.GetFiles(scherm1);

        foreach (string file in files)
        {
            FileInfo fi = new FileInfo(file);

            if (fi.LastAccessTime < DateTime.Now.AddMilliseconds(-5000))
            {
                try
                {
                    Process[] runningProcs = Process.GetProcesses();

                    foreach (Process proc in runningProcs)
                    {
                        foreach (int pid in pids)
                        {

                            if (pid == proc.Id)
                            {
                                TryKillProcessByMainWindowHwnd(pid);
                            }
                        }
                    }
                }

                catch { }
                Thread.Sleep(500);
                fi.Delete();
            }

        }
    }

works like charm !