How do I run a simple bit of code in a new thread?

Question

I have a bit of code that I need to run in a different thread than the GUI as it currently causes the form to freeze whilst the code runs (10 seconds or so).

Assume I have never created a new thread before; what's a simple/basic example of how to do this in C# and using .NET Framework 2.0 or later?

Answer 1

another option, that uses delegates and the Thread Pool...

assuming 'GetEnergyUsage' is a method that takes a DateTime and another DateTime as input arguments, and returns an Int...

// following declaration of delegate ,,,
public delegate long GetEnergyUsageDelegate(DateTime lastRunTime, 
                                            DateTime procDateTime);

// following inside of some client method 
GetEnergyUsageDelegate nrgDel = GetEnergyUsage;                     
IAsyncResult aR = nrgDel.BeginInvoke(lastRunTime, procDT, null, null);
while (!aR.IsCompleted) Thread.Sleep(500);
int usageCnt = nrgDel.EndInvoke(aR);

Answer 2

Quick and dirty, but it will work:

Using at top:

using System.Threading;

simple code:

static void Main( string[] args )
{
    Thread t = new Thread( NewThread );
    t.Start();
}

static void NewThread()
{
    //code goes here
}

I just threw this into a new console application for an exmaple

Answer 3

There are many ways of running separate threads in .Net, each has different behaviors. Do you need to continue running the thread after the GUI quits? Do you need to pass information between the thread and GUI? Does the thread need to update the GUI? Should the thread do one task then quit, or should it continue running? The answers to these questions will tell you which method to use.

There is a good async method article at the Code Project web site that describes the various methods and provides sample code.

Note this article was written before the async/await pattern and Task Parallel Library were introduced into .NET.

Answer 4

Try using the BackgroundWorker class. You give it delegates for what to run, and to be notified when work has finished. There is an example on the MSDN page that I linked to.

Answer 5

Here is another option:

Task.Run(()=>{
//Here is a new thread
});

Answer 6

BackgroundWorker seems to be best choice for you.

Here is my minimal example. After you click on the button the background worker will begin working in background thread and also report its progress simultaneously. It will also report after the work completes.

using System.ComponentModel;
...
    private void button1_Click(object sender, EventArgs e)
    {
        BackgroundWorker bw = new BackgroundWorker();

        // this allows our worker to report progress during work
        bw.WorkerReportsProgress = true;

        // what to do in the background thread
        bw.DoWork += new DoWorkEventHandler(
        delegate(object o, DoWorkEventArgs args)
        {
            BackgroundWorker b = o as BackgroundWorker;

            // do some simple processing for 10 seconds
            for (int i = 1; i <= 10; i++)
            {
                // report the progress in percent
                b.ReportProgress(i * 10);
                Thread.Sleep(1000);
            }

        });

        // what to do when progress changed (update the progress bar for example)
        bw.ProgressChanged += new ProgressChangedEventHandler(
        delegate(object o, ProgressChangedEventArgs args)
        {
            label1.Text = string.Format("{0}% Completed", args.ProgressPercentage);
        });

        // what to do when worker completes its task (notify the user)
        bw.RunWorkerCompleted += new RunWorkerCompletedEventHandler(
        delegate(object o, RunWorkerCompletedEventArgs args)
        {
            label1.Text = "Finished!";
        });

        bw.RunWorkerAsync();
    }

Note:

• I put everything in single method using C#'s anonymous method for simplicity but you can always pull them out to different methods.
• It is safe to update GUI within ProgressChanged or RunWorkerCompleted handlers. However, updating GUI from DoWork will cause InvalidOperationException.