How do I find out if a process is already running using c#?

Question

I have C# winforms application that needs to start an external exe from time to time, but I do not wish to start another process if one is already running, but rather switch

Answer 1

Mnebuerquo wrote:

Also, I had source code access to the process I was trying to start. If you can not modify the code, adding the mutex is obviously not an option.

I don't have source code access to the process I want to run.

I have ended up using the proccess MainWindowHandle to switch to the process once I have found it is alread running:

[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
 public static extern bool SetForegroundWindow(IntPtr hWnd);

Answer 2

I have used the AppActivate function in VB runtime to activate an existing process. You will have to import Microsoft.VisualBasic dll into the C# project.

using System;
using System.Diagnostics;
using Microsoft.VisualBasic;

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            Process[] proc = Process.GetProcessesByName("notepad");
            Interaction.AppActivate(proc[0].MainWindowTitle);
        }
    }
}

Answer 3

You can use LINQ as well,

var processExists = Process.GetProcesses().Any(p => p.ProcessName.Contains("<your process name>"));