Question

i have a method that creates a Process calling a console app.

double myProcess()
{
    double results;

    Process process = new Process();
    process.EnableRaisingEvents = true;
    process.OutputDataReceived += new DataReceivedEventHandler(process_OutputDataReceived);
    process.StartInfo.FileName = filename;
    process.StartInfo.Arguments = argument;
    process.StartInfo.UseShellExecute = false;
    process.StartInfo.RedirectStandardOutput = true;
    process.StartInfo.CreateNoWindow = true;
    process.Start(); 
    process.BeginOutputReadLine();
    process.WaitForExit();

    return results;
}

static void process_OutputDataReceived(object sender, DataReceivedEventArgs e)
{
    string stringResults = (string)e.Data;
    .
    .
    do some work on stringResults...
    .
    .
    results = stringResults;
}

my problem is,how do i send data from process_OutputDataReceived back to myProcess? I cannot use singleton as there are possibilities that this process will be executed in multiple thread.

Answer 1

You don’t need a separate method for the OutputDataReceived handler; you can use an anonymous method to set the results variable directly:

process.OutputDataReceived += (sender, e) => results = e.Data;

(Also, should results be string or double?)

Edit: A couple of alternatives for when you need to do more work in the handler:

process.OutputDataReceived +=
   (sender, e) =>
   {
        string stringResults = e.Data;
        // do some work on stringResults...
        results = stringResults;
   }

// or

process.OutputDataReceived +=
   delegate(object sender, DataReceivedEventArgs e)
   {
        string stringResults = e.Data;
        // do some work on stringResults...
        results = stringResults;
   }