C#

// in method called by worker thread
try
{
  //do work that might take a while
}catch(Exception e)
{
  // * clean up resources
  // * if the exception is a ThreadAbortException, exit gracefully
}

// In the button click event
Thread myThread = new Thread (new ThreadStart (ThreadFunc));

if (button1.Text == "Connect")
{
        // this is called
	myThread.Start ();
	button1.Text = "Disconnect";
}
else
{
	popClient.DestroyConnection ();
	button1.Text = "Connect";
        // At this point the thread still isn't started (IsAlive is false)
	myThread.Abort ();
	myThread.Join ();
}


public void ThreadFunc ()
{// How can I use "popClient" in both main() and here in the threadfunc?	
Networking.PopClient popClient = new networking.PopClient (cboServer.Text, txtUser.Text, txtPassword.Text);

	bool bConnected = popClient.CreateConnection ();

	if (!bConnected)
	{
		lblError.Text = popClient.LastError;
		return;
	}

	int count = popClient.GetMailBoxCount ();
	int size = popClient.GetMailBoxSize ();

	lblMessageCount.Text = Convert.ToString (count);
	lblQuotaUsed.Text = Convert.ToString (size);
}

// In the button click event
Thread myThread = new Thread (new ThreadStart (ThreadFunc));
if (button1.Text == "Connect")
{       // this is called	
        myThread.Start ();
	button1.Text = "Disconnect";
}else{
	myThread.Abort ();
	myThread.Join ();
}
 
 
 
public void ThreadFunc ()
{// How can I use "popClient" in both main() and here in the threadfunc?
	Networking.PopClient popClient = new networking.PopClient (cboServer.Text, 
                        txtUser.Text, txtPassword.Text);
	try{
            bool bConnected = popClient.CreateConnection ();
            if (!bConnected)
            {	
                    lblError.Text = popClient.LastError;
                    return;
            }
            int count = popClient.GetMailBoxCount ();
            int size = popClient.GetMailBoxSize ();	
            lblMessageCount.Text = Convert.ToString (count);
            lblQuotaUsed.Text = Convert.ToString (size);
        }catch(Exception e){
            //do any error handling here
        }finally{
            popClient.DestroyConnection();
            OnFinished();
        }
}
 
public event EventHandler Finished;
protected OnFinished()
{
    if(Finished!=null)
        Finished.BeginInvoke(this,EventArgs.Empty,null,null);
}
 
 
 
//should be connected to the Finished event
private void JobFinished(object sender, EventArgs e)
{
    button1.Text = "Connect";
}