How to get the process Id safely after process.Start()?

Question

When a program is copied to many locations and then is started independently, sometimes error may appear:

ProcessStartInfo startInfo = new ProcessStartInfo(exePath);
startInfo.WindowStyle = ProcessWindowStyle.Hidden;
startInfo.ErrorDialog = false;

Process process = new Process() { StartInfo = startInfo };
bool isStarted = process.Start();
int processId = process.Id; // Failed as bellow When the isStarted is false

System.InvalidOperationException: No process is associated with this object.

possible duplicate of [getting PID of process started by Process.start()](http://stackoverflow.com/questions/12892268/getting-pid-of-process-started-by-process-start) — Daniel Casserly, Jul 08 '15 at 10:05
It's just likely that your process has started, but encountered an immediate failure, like unhandled exception, and terminated immediately. In this case the bool flag for `IsStarted` will be set to false and you don't get process id. If you really-really need this captured, i'd assume you may need some sort of a driver to subscribe to a process start kernel call. You may be out of luck otherwise. In most situations you don't *really* need to capture an attempt to start a process. — oleksii, Jul 08 '15 at 10:26
@King Add process.Exited event to get idea when it exited `process.Exited += Process_Exited;` — NASSER, Jul 08 '15 at 10:41
Normally, the Process class should hold a handle to that process. This stabilizes the ID. This should just work. Is that your real code? — usr, Jul 08 '15 at 12:13
Are you really starting exe files? I don't know how isStarted could ever be false for those. Set UseShellExecute = false. — usr, Jul 08 '15 at 12:15

score 1 · Answer 1 · answered Jul 08 '15 at 12:16

Since you are starting EXE files you don't need the UseShellExecute feature. For some unfathomable reason UseShellExecute is set to true by default. Using it entails a lot of complexity.

Set UseShellExecute to false and Start should always return true. Then, the ID should always be valid. Be sure to dispose of the Process instance.

How to get the process Id safely after process.Start()?

1 Answers1