protected void cmdAsynchronous_Click(object sender, EventArgs e)
{
// Record the start time.
DateTime startTime = DateTime.Now;
// Start the web service on another thread.
EmployeesService proxy = new EmployeesService();
GetEmployeesDelegate async = new GetEmployeesDelegate(proxy.GetEmployeesSlow);
IAsyncResult handle = async.BeginInvoke(null, null);
// Perform some other time-consuming tasks.
DoSomethingSlow();
// Retrieve the result. If it isn't ready, wait.
try
{
GridView1.DataSource = async.EndInvoke(handle);
}
catch (Exception err)
{
lblInfo.Text = "Problem contacting web service.";
return;
}
GridView1.DataBind();
// Determine the total time taken.
TimeSpan timeTaken = DateTime.Now.Subtract(startTime);
lblInfo.Text = "Asynchronous operations took " + timeTaken.TotalSeconds +
" seconds.";
}
protected void cmdMultiple_Click(object sender, EventArgs e)
{
// Record the start time.
DateTime startTime = DateTime.Now;
EmployeesService proxy = new EmployeesService();
GetEmployeesDelegate async = new GetEmployeesDelegate(proxy.GetEmployeesSlow);
// Call three methods asynchronously.
IAsyncResult handle1 = async.BeginInvoke(null, null);
IAsyncResult handle2 = async.BeginInvoke(null, null);
IAsyncResult handle3 = async.BeginInvoke(null, null);
// Create an array of WaitHandle objects.
WaitHandle[] waitHandles = {handle1.AsyncWaitHandle,
handle2.AsyncWaitHandle, handle3.AsyncWaitHandle};
// Wait for all the calls to finish.
WaitHandle.WaitAll(waitHandles);
// You can now retrieve the results.
DataSet ds1 = async.EndInvoke(handle1);
DataSet ds2 = async.EndInvoke(handle2);
DataSet ds3 = async.EndInvoke(handle3);
// Merge all the results into one table and display it.
DataSet dsMerge = new DataSet();
dsMerge.Merge(ds1);
dsMerge.Merge(ds2);
dsMerge.Merge(ds3);
GridView1.DataSource = dsMerge;
GridView1.DataBind();
// Determine the total time taken.
TimeSpan timeTaken = DateTime.Now.Subtract(startTime);
lblInfo.Text = "Calling three methods took " + timeTaken.TotalSeconds +
" seconds.";
}