Ways to call methods asynchronously

Here I demonstrate two simple ways to execute a method asynchronously in .NET app.

A. Using AsyncWaitHandle

This is a very useful way to allow your application to process other task. I used this technique most when loading data in my UI, like, loading data into the dropdownlist simultaneously.

1. Create a delegate that will handle the asynchronous request

public delegate CountryReadOnlyCollection LoadList();

2. Use the delegate to execute asynchronous request

LoadList loadList = new LoadList(CountryReadOnlyCollection.GetList);
IAsyncResult r = loadList.BeginInvoke(null, null);
// Do several task here...

// WaitOne will wait untill the task completed before proceding to the next step
r.AsyncWaitHandle.WaitOne();
CountryReadOnlyCollectionlist = loadList.EndInvoke(r);
Trace.WriteLine(string.Format("Total Count: {0}", list.Count));