读取过程的标准输出，始终为空

Question

Running this code:

Process p = new Process();
p.StartInfo.UseShellExecute = false;
p.StartInfo.FileName = "tool.exe";
p.Start();
p.WaitForExit();

Makes tool.exe run, and output some content on standard output. However, if I try to capture the content using:

Process p = new Process();
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.CreateNoWindow = true;
p.StartInfo.FileName = "tool.exe";
p.Start();
string output = p.StandardOutput.ReadToEnd();
p.WaitForExit();

Console.WriteLine(output);
Console.ReadLine();

Then nothing gets outputted, ie my variable "output" is always empty.

I've verified that tool.exe indeed outputs to standard output (and not standard error).

Anyone have a clue of what's going on? Starting to feel stupid here, as it seems to be a real text book example...

Answer 1

p.OutputDataReceived += new DataReceivedEventHandler
        (
            delegate(object sender, DataReceivedEventArgs e)
            {                   
                using (StreamReader output = p.StandardOutput)
                {
                    retMessage = output.ReadToEnd();
                }
            }
        );

Try this :)