C# Run long CMD process and capture output to WinForm

Question

I am wanting to run a CMD process and instead of a Console Window have all the output sent to a TextBox on the Winform calling it.
I have worked through several ways to do this, but not having any luck in getting a solution to work.
I have posted some code below, which I have found documented similar on many posts, but I keep getting stuck with this error:

System.InvalidOperationException: 'StandardOut has not been redirected or the process hasn't started yet.'
On the line using: BeginOutputReadLine();

My Test Code:

private void CMD_Process()
{
Process p = new Process();
p.StartInfo = new ProcessStartInfo("CMD.EXE")
{
RedirectStandardInput = true,
UseShellExecute = false,
Arguments = @"/C DIR C:\"
};
p.OutputDataReceived += p_OutputDataReceived;
p.ErrorDataReceived += p_ErrorDataReceived;
p.Start();
p.BeginOutputReadLine();
}

private void p_ErrorDataReceived(object sender, DataReceivedEventArgs e)
{
this.BeginInvoke(new Action(() => textBoxProgress.AppendText(e.Data)));
}

private void p_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
this.BeginInvoke(new Action(() => textBoxProgress.AppendText(e.Data)));
}

I am wanting to keep this solution as simple as possible.
My aim to to run a CMD process and have all output displayed live on the WinForm while it is running.

Thanks for any help on this.

Answer 1

Hi MrCheese-8474,
Please try the following code:

private void Form1_Load(object sender, EventArgs e)  
{  
    System.Diagnostics.Process process = new System.Diagnostics.Process();  
    process.StartInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden;  
    process.StartInfo.FileName = "cmd.exe";  
    process.StartInfo.Arguments = @"/C DIR C:\";  
    process.StartInfo.UseShellExecute = false;  
    process.StartInfo.CreateNoWindow = true;  
    process.StartInfo.RedirectStandardOutput = true;  
    process.StartInfo.RedirectStandardInput = true;  
    process.Start();  
    string q = "";  
    while (!process.HasExited)  
    {  
        q += process.StandardOutput.ReadToEnd();  
    }  
    textBox1.Text = q;  
//    MessageBox.Show(q);  
}  

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Answer 2

Try removing RedirectStandardInput=true and replace it with RedirectStandardOutput=true, RedirectStandardError=true.