private void Callback(IAsyncResult asyncResult)
{
// Retrieve the proxy from state.
EmployeesService proxy = (EmployeesService)asyncResult.AsyncState;
// Complete the call.
DataSet ds = proxy.EndGetEmployees(asyncResult);
// Update the user interface on the right thread.
this.Invoke(new UpdateGridDelegate(UpdateGrid), new object[] { ds });
}
private void cmdMultiple_Click(object sender, System.EventArgs e)
{
// Record the start time.
DateTime startTime = DateTime.Now;
EmployeesService proxy = new EmployeesService();
// Call three methods asynchronously.
IAsyncResult async1 = proxy.BeginGetEmployees(null, null);
IAsyncResult async2 = proxy.BeginGetEmployees(null, null);
IAsyncResult async3 = proxy.BeginGetEmployees(null, null);
// Create an array of WaitHandle objects.
WaitHandle[] waitHandles = { async1.AsyncWaitHandle,
async2.AsyncWaitHandle, async3.AsyncWaitHandle };
// Wait for all the calls to finish.
WaitHandle.WaitAll(waitHandles);
// You can now retrieve the results.
DataSet ds1 = proxy.EndGetEmployees(async1);
DataSet ds2 = proxy.EndGetEmployees(async2);
DataSet ds3 = proxy.EndGetEmployees(async3);
DataSet dsMerge = new DataSet();
dsMerge.Merge(ds1);
dsMerge.Merge(ds2);
dsMerge.Merge(ds3);
DataGrid1.DataSource = dsMerge;
DataGrid1.DataBind();
// Determine the total time taken.
TimeSpan timeTaken = DateTime.Now.Subtract(startTime);
lblInfo.Text = "Calling three methods took " + timeTaken.TotalSeconds + " seconds.";
}
private void cmdAsynchronous_Click(object sender, System.EventArgs e)
{
// Record the start time.
DateTime startTime = DateTime.Now;
// Start the web service.
EmployeesService proxy = new EmployeesService();
IAsyncResult handle = proxy.BeginGetEmployees(null, null);
// Perform some other time-consuming tasks.
DoSomethingSlow();
// Retrieve the result. If it isn't ready, wait.
DataGrid1.DataSource = proxy.EndGetEmployees(handle);
DataGrid1.DataBind();
// Determine the total time taken.
TimeSpan timeTaken = DateTime.Now.Subtract(startTime);
lblInfo.Text = "Asynchronous operations took " + timeTaken.TotalSeconds + " seconds.";
}