Visual Basic 2008 Recipes: A Problem-Solution Approach

4.2. Execute a Method Asynchronously

Problem

You need to start execution of a method and continue with other tasks while the method runs on a separate thread. After the method completes, you need to retrieve the method's return value.

Solution

Declare a delegate with the same signature as the method you want to execute. Create an instance of the delegate that references the method. Call the BeginInvoke method of the delegate instance to start executing your method. Use the EndInvoke method to determine the method's status as well as obtain the method's return value if complete.

How It Works

Typically, when you invoke a method, you do so synchronously, meaning that the calling code blocks until the method is complete. Most of the time, this is ...