Application #9. Use Callbacks

This application demonstrates how to perform callbacks using both interfaces and delegates.

Building Upon...

Application #79: Use Thread Pooling

Application #84: Asynchronous Calls

New Concepts

Visual Basic .NET makes it easy for you to call a function by its address. This is an important feature because that’s how you set up a callback.


What is a callback function, and why would you need one? A callback function is a reference to a method that you can pass to a second method. At some point, the second method invokes the reference, thereby calling back to the first method. You can use a callback to notify you when a job is done by calling a procedure in your code. First you initiate the ...

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