ProcessStartInfo psi = new ProcessStartInfo();
psi.FileName = @"程序名";
psi.Arguments = @"参数";
//psi.CreateNoWindow = true;
psi.WindowStyle = ProcessWindowStyle.Hidden;
Task.Factory.StartNew(
new Action(() => Process.Start(psi).WaitForExit())
).ContinueWith(new Action<Task>((t) => MessageBox.Show($"线程{t.Id}运行完毕.")));