Asynchronous method execution using delegates

[Full article]This month I'll discuss the use of delegates to execute a method in an asynchronous fashion. I'll assume that you already know the fundamentals of programming with delegates, but if not, you should read the December 2002 and January 2003 Basic Instincts columns.
There are a number of scenarios in which asynchronous execution can be a valuable design technique. For example, you should use asynchronous execution in a Windows® Forms application when you want to execute a long-running command without blocking the responsiveness of the user interface. As you will see, programming with delegates makes it relatively easy to run a command asynchronously on a secondary thread. That means you can build a Windows Forms application that executes long-running calls across the network without freezing the user interface.
Executing methods asynchronously can also serve as a useful technique for a server-side application. Imagine you are writing the code behind an ASP.NET page to service a client request. What should you do if your code needs to execute two or more time-consuming calls across a network? For example, imagine you are required to write an ASP.NET page that must run a query against a remote database and also must execute a SOAP method on a remote Web Service to complete its work. If you don't use asynchronous method execution, you can only make one call across the network at a time. This means you can't start the second network call until the first network call returns. Asynchronous method execution using delegates lets you execute two or more network calls at the same time. This can significantly reduce the time it takes to process a server-side ASP.NET request, increasing the responsiveness of your application from the user's perspective.