How can I know if a process is running?

Question

When I get a reference to a System.Diagnostics.Process, how can I know if a process is currently running?

Answer 1

This is a way to do it with the name:

Process[] pname = Process.GetProcessesByName("notepad");
if (pname.Length == 0)
  MessageBox.Show("nothing");
else
  MessageBox.Show("run");

You can loop all process to get the ID for later manipulation:

Process[] processlist = Process.GetProcesses();
foreach(Process theprocess in processlist){
   Console.WriteLine("Process: {0} ID: {1}", theprocess.ProcessName, theprocess.Id);
}

Answer 2

Process.GetProcesses() is the way to go. But you may need to use one or more different criteria to find your process, depending on how it is running (i.e. as a service or a normal app, whether or not it has a titlebar).

Answer 3

It depends on how reliable you want this function to be. If you want to know if the particular Process instance you have is still running and available with 100% accuracy then you are out of luck. The reason being that from the managed process object there are only 2 ways to identify the process

The first is the Process Id. Unforunately process id's are not unique and can be recycled. Searching the process list for a matching Id will only tell you that there is a process with the same id running, but it's not necessarily your process.

The second item is the Process Handle. It has the same problem though as the Id and it's more awkaard to work with.

If you're looking for medium level reliability then checking the current process list for a process of the same ID is sufficient.

Answer 4

Maybe (probably) I am reading the question wrongly, but are you looking for the HasExited property that will tell you that the process represented by your Process object has exited (either normally or not).

If the process you have a reference to has a UI you can use the Responding property to determine if the UI is currently responding to user input or not.

You can also set EnableRaisingEvents and handle the Exited event (which is sent asychronously) or call WaitForExit() if you want to block.

Answer 5

Synchronous solution :

void DisplayProcessStatus(Process process)
{
    process.Refresh();  // Important


    if(process.HasExited)
    {
        Console.WriteLine("Exited.");
    }
    else
    {
        Console.WriteLine("Running.");
    } 
}

Asynchronous solution:

void RegisterProcessExit(Process process)
{
    // NOTE there will be a race condition with the caller here
    //   how to fix it is left as an exercise
    process.Exited += process_Exited;
}

static void process_Exited(object sender, EventArgs e)
{
   Console.WriteLine("Process has exited.");
}

Answer 6

This is the simplest way I found after using reflector. I created an extension method for that:

public static class ProcessExtensions
{
    public static bool IsRunning(this Process process)
    {
        if (process == null) 
            throw new ArgumentNullException("process");

        try
        {
            Process.GetProcessById(process.Id);
        }
        catch (ArgumentException)
        {
            return false;
        }
        return true;
    }
}

The Process.GetProcessById(processId) method calls the ProcessManager.IsProcessRunning(processId) method and throws ArgumentException in case the process does not exist. For some reason the ProcessManager class is internal...