Question

My winform application is launched by another application (the parent), I need determine the pid of the application which launch my application using C#.

Answer 1

WMI is the easier way to do this in C#. The Win32_Process class has the ParentProcessId property. Here’s an example:

using System;
using System.Management;  // <=== Add Reference required!!
using System.Diagnostics;

class Program {
    public static void Main() {
        var myId = Process.GetCurrentProcess().Id;
        var query = string.Format("SELECT ParentProcessId FROM Win32_Process WHERE ProcessId = {0}", myId);
        var search = new ManagementObjectSearcher("root\\CIMV2", query);
        var results = search.Get().GetEnumerator();
        results.MoveNext();
        var queryObj = results.Current;
        var parentId = (uint)queryObj["ParentProcessId"];
        var parent = Process.GetProcessById((int)parentId);
        Console.WriteLine("I was started by {0}", parent.ProcessName);
        Console.ReadLine();
    }
}

Output when run from Visual Studio:

I was started by devenv