Process.Start blocks

Question

I call Process.Start, but it blocks the current thread.

pInfo = new ProcessStartInfo("C:\\Windows\\notepad.exe");

// Start process
mProcess = new Process();
mProcess.StartInfo = pInfo;
if (mProcess.Start() == false) {
    Trace.TraceError("Unable to run process {0}.");
}

Even when the process is closed, the code no longer responds.

But should Process.Start really block? What's happening?

(The process starts correctly)

---

using System;
using System.Diagnostics;
using System.Threading;
using System.Windows.Forms;

namespace Test
{
    class Test
    {
        [STAThread]
        public static void Main()
        {
            Thread ServerThread = new Thread(AccepterThread);
            ServerThread.Start();

            Console.WriteLine (" ---  Press ENTER to stop service ---");
            while (Console.Read() < 0) { Application.DoEvents(); }

            Console.WriteLine("Done.");
        }

        public static void AccepterThread(object data)
        {
            bool accepted = false;

            while (true) {
                if (accepted == false) {
                    Thread hThread = new Thread(HandlerThread);
                    accepted = true;
                    hThread.Start();
                } else
                    Thread.Sleep(100);
            }
        }

        public static void HandlerThread(object data)
        {
            ProcessStartInfo pInfo = new ProcessStartInfo("C:\\Windows\\notepad.exe");

            Console.WriteLine("Starting process.");

            // Start process
            Process mProcess = new Process();
            mProcess.StartInfo = pInfo;
            if (mProcess.Start() == false) {
                Console.WriteLine("Unable to run process.");
            }
            Console.WriteLine("Still living...");
        }
    }
}

Console output:

--- Press ENTER to stop the service --- Start the process.

---

Found:

[STAThread]

Makes the lock Process.Start. I read STAThread and multithreading , but I can not associate concepts with the behavior of Process.Start.

AFAIK, STAThread is required by Windows.Form. How to solve this problem when using Windows.Form?

---

News for Hell:

If I rebuild my application, the first time I start the application I work correctly, but if I stop debugging and reboot again, the problem is araise.

, .

Answer 1

, Process.Start ... , -.

:

using System;
using System.Diagnostics;

public class Test
{
    static void Main()
    {
        Process p = new Process { 
            StartInfo = new ProcessStartInfo("C:\\Windows\\notepad.exe")
        };
        p.Start();
        Console.WriteLine("See, I'm still running");
    }
}

"See, I'm still running" - ?

Answer 2

ProcessStartInfo UseShellExecute false ( - true). :

pInfo = new ProcessStartInfo("C:\\Windows\\notepad.exe");
pInfo.UseShellExecute = false;

// Start process
mProcess = new Process();
mProcess.StartInfo = pInfo;
if (mProcess.Start() == false) {
    Trace.TraceError("Unable to run process {0}.");
}

, , .

Answer 3

, WinForms, , .

Jon Skeet , , . Excel, .

using System;
using System.Diagnostics;
using static System.Console;
using System.Threading;

class Program {

    static void Main(string[] args) {

        WriteLine("About to start process...");

        //Toggle which method is commented out:

        //StartWithPath();  //Blocking
        //StartWithInfo();  //Blocking
        StartInNewThread(); //Not blocking

        WriteLine("Process started!");
        Read();
    }

    static void StartWithPath() {
        Process.Start(TestPath);
    }

    static void StartWithInfo() {
        var p = new Process { StartInfo = new ProcessStartInfo(TestPath) };
        p.Start();
    }

    static void StartInNewThread() {
        var t = new Thread(() => StartWithPath());
        t.Start();
    }

    static string TestPath =
        Environment.GetFolderPath(Environment.SpecialFolder.Desktop) +
        "\\test.xlsx";
}

StartWithPath StartWithInfo . " " , Excel .

StartInNewThread , Excel .

Answer 4

We had this problem when running the .bat script, which was on a network drive in a different domain (we have two trusted domains). I ran the C # remote debugger and, of course, Process.Start () blocked endlessly.

When this task is repeated in the power shell, a security dialog box appears:

As for the decision, that was the direction we went. The person who performed the work with the changed GPO domain fulfilled the trust.