Process ID of process Started by Process Start

Question

I am trying to kill the process by process ID which I am saving when the process start. But the process ID which I am capturing doesn't exists when I try to kill the process from code behind.

This is the code below to start the process and capture the process ID.

private List<int> pids = new List<int>();
public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            pids.Clear();
            Process myprocess= new Process();

            myprocess.StartInfo.FileName = Environment.ExpandEnvironmentVariables(@"%SystemRoot%\system32\cmdkey.exe");
            myprocess.StartInfo.Arguments = "C:\\rdp\\RemoteIn.rdp";
            myprocess.Start();
            pids.Add(myprocess.Id);          
        }

        private void terminateAll()
        {
            //foreach (var p in pids) p.Kill();

            foreach (var i in pids)
            {
                Process p = Process.GetProcessById(i);
                p.Kill();

            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            terminateAll();
        }

When I click button to terminate the process it shows following error.

enter image description here

Is there any way to fix this.

After using Palani Kumar code, I am getting below exception. enter image description here

Form Looks like this

enter image description here

Try saving the Process object in your list, not just the Id. — Blorgbeard, May 25 '15 at 02:35
Yes, rather than storing the pids, just store the process itself, then you don't even have to call `Process.GetProcessById(i);` — spender, May 25 '15 at 02:36
possible duplicate of [getting PID of process started by Process.start()](http://stackoverflow.com/questions/12892268/getting-pid-of-process-started-by-process-start) — Hari Prasad, May 25 '15 at 02:36
Change `pids` from being a `List` to a `List` then instead of doing `pids.Add(notePad.Id);` you do `pids.Add(notePad);` — Scott Chamberlain, May 25 '15 at 03:03
Side note: there is very good chance that exception tells you the truth - you are launching other process via CMD - so CMD is free to exist after that. — Alexei Levenkov, May 25 '15 at 03:10
just use instead of id to process name Process p=Process.GetProcessesByName("YourProcessName"); — Jagadeesh Govindaraj, Jun 22 '15 at 06:33

Palanikumar · Accepted Answer · 2015-06-22T09:13:25.787

1

I don't know why you are declared pids as List<int> and cleared the list (pids.Clear();) on button click event. Anyway the below will work for creating multiple processes also.

EDIT: As so far discussed with Amrit. The Windows 8 creating sub processes for mstsc with connecting same domain. So I slightly modified my code.

    private void button1_Click(object sender, EventArgs e)
    {
        //pids.Clear();
        Process myprocess = new Process();

        myprocess.StartInfo.FileName = Environment.ExpandEnvironmentVariables(@"%SystemRoot%\syswow64\mstsc.exe");
        myprocess.StartInfo.Arguments = "C:\\rdp\\RemoteIn.rdp";
        myprocess.Start();
        Thread.Sleep(100);
        /* Edit */
        Process proc = Process.GetProcessesByName("mstsc").FirstOrDefault(x => !pids.Any(y => y == x.Id));
        if(proc != null)
        {
           pids.Add(proc.Id);
        }
    }

And

    private void terminateAll()
    {
        foreach (var i in pids)
        {
            try
            {
                Process p = Process.GetProcessById(i);
                p.Kill();
            }
            catch (Exception ex)
            {
                //throw exception if we close the mstsc manually
            }
        }
    }

edited Jun 22 '15 at 09:13

answered Jun 22 '15 at 06:27

Palanikumar

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It works like charm if i just open one .rdp file. But when i open another .rdp file it throws above error. – Amrit Sharma Jun 22 '15 at 07:04
did you comment this line "pids.Clear();" – Palanikumar Jun 22 '15 at 07:05
Yes I did comment out the pids.Clear() – Amrit Sharma Jun 22 '15 at 07:07
Amrit, now do you have issue with opening more than one rdp files? or just you want to open only one rdp and you are fine with that? – Palanikumar Jun 22 '15 at 07:10
I need to open multiple .rdp files. – Amrit Sharma Jun 22 '15 at 07:11
Hmm... I tested this with multiple and that was working fine. Then try to increase the value in Thread.Sleep and check if the process id match with the PID created in Task Manager. – Palanikumar Jun 22 '15 at 07:13
Please refer above how the draft form looks like. – Amrit Sharma Jun 22 '15 at 07:13
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/81150/discussion-between-palani-kumar-and-amrit-sharma). – Palanikumar Jun 22 '15 at 07:15

Oleg · Answer 2 · 2015-06-22T07:52:48.333

I'm not sure why you hold

private List<int> pids = new List<int>();

instead of usage just the list of Process directly

private List<Process> processes = new List<Process>();

It's important to understand that the Process object have security descriptor. Everybody can see the existence of the process, someone can open the process for reading information or for waiting for the the end of process. Opening for killing require more rights. The process handle returned by CreateProcess have full permissions. So holding of Process object used for creating the process gives you such advantages.

I would recommend you additionally to test HasExited property of Process object before calling of Kill() method. One can consider to use OnExited additionally (see here) to remove the process if it will be closed by the user. You should call Close() method of Process object in any way before removing from the processes list and consider to use CloseMainWindow() instead of Kill() method. You should just test both methods (CloseMainWindow() and Kill()) and to choose the best for your case.

Process ID of process Started by Process Start

2 Answers2