Asynchronous programming.

The code snippet below is a stripped down, example from a real app and illustrates a problem I am experiencing. The idea is to start and stop a process that works in the background (using asynchronous delegate invocation). The process loops until a flag is set to true. In the real app, the process invoves a specific closing-down process and hence the need to wait for the processing to terminate gracefully.  

The problem is the application hangs (for ever) on the WaitOne() call. If I comment this line out, the app appears to work OK. Have I misunderstood how to use the WaitOne() call I need to wait in the main thread for the processing to terminate before I can continue.

BTW I am using Visual Studio 2005 RC1.

public partial class AsyncForm : Form

{

public AsyncForm()

{

InitializeComponent();

}

private delegate void WorkerHandler();

private WorkerHandler Worker;

private IAsyncResult IAResult;

private bool IsDone ;

private void DoWork()

{

while (!IsDone)

{

Thread.Sleep(1500);

}

}

private void AsyncForm_Load(object sender, EventArgs e)

{

btnStart.Enabled = true;

btnStop.Enabled = false;

}

private void btnStart_Click(object sender, EventArgs e)

{

IsDone = false;

Worker = DoWork;

IAResult = Worker.BeginInvoke(null, null);

btnStart.Enabled = false;

btnStop.Enabled = true;

}

private void btnStop_Click(object sender, EventArgs e)

{

btnStop.Enabled = false;

IsDone = true;

IAResult.AsyncWaitHandle.WaitOne();

btnStart.Enabled = true;

}

}