c# and process to control

Question

I stuck with control logging.

private void btPullLinks_ItemClick(object sender, DevExpress.XtraBars.ItemClickEventArgs e)
        {
            Run_cmd();
        }

        public void Run_cmd()
        {
            StringBuilder outputBuilder;
            ProcessStartInfo processStartInfo;
            Process process;

            outputBuilder = new StringBuilder();

            processStartInfo = new ProcessStartInfo();
            processStartInfo.CreateNoWindow = true;
            processStartInfo.RedirectStandardOutput = true;
            processStartInfo.RedirectStandardInput = true;
            processStartInfo.UseShellExecute = false;
            processStartInfo.Arguments = @"c:.......py";
            processStartInfo.FileName = @"...../python.exe";

            process = new Process();
            process.StartInfo = processStartInfo;
            process.EnableRaisingEvents = true;
            process.OutputDataReceived += new DataReceivedEventHandler
            (
                delegate (object sender, DataReceivedEventArgs e)
                {
                    outputBuilder.Append(e.Data);
                    txtoutpute.text = e.Data;
                }
            );

            process.Start();
            process.BeginOutputReadLine();
            process.WaitForExit();
            process.CancelOutputRead();

            // use the output
            outputBuilder.ToString();

        }

How to log the output in real time into control ?

My goal is to log the data from delegate function to .Net control.

Tried with solutions offered here. Cross-thread operation not valid: Control 'textBox1' accessed from a thread other than the thread it was created on [duplicate]

What problems are you having? Have you checked `txtoutpute.InvokeRequired`? Are you getting an error? — 001, Mar 20 '20 at 17:01
@JohnnyMopp throwing error 'cross-thread operation not valid....' because i tried to log into txtOutput inside delegate function — Rookie programmer, Mar 20 '20 at 17:05
This error should not happen because you are writing to the textbox in an event handler. But if you can't get rid of it, try (in Program.cs -> Main()) `Form.CheckForIllegalCrossThreadCalls = false;` — Oguz Ozgul, Mar 20 '20 at 17:10

score 1 · Accepted Answer · answered Mar 20 '20 at 17:23

I don't know why, in an event handler, the runtime throws this exception. Normally, the run-time handles the calling context and executes the event handler routine by the main thread.

https://learn.microsoft.com/en-us/dotnet/framework/winforms/controls/how-to-make-thread-safe-calls-to-windows-forms-controls

But if you can't get rid of it, try (in Program.cs -> Main())

Form.CheckForIllegalCrossThreadCalls = false;

c# and process to control

1 Answers1