Professional Visual Basic 2012 and .NET 4.5 Programming

Chapter 6

Exception Handling and Debugging

What's in this chapter?

The general principles behind exception handling

The Try…Catch…Finally structure for trapping exceptions

How to send exceptions to other code using the Throw statement

Obtaining information about an exception by using the exception object's methods and properties

Event logging and simple tracing, and how you can use these methods to obtain feedback about how your program is working

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Production quality applications need to handle unexpected conditions. In .NET this is done with the structured exception syntax. When an unexpected condition arises .NET does not generate error codes. Instead when an unexpected condition occurs, the CLR creates a special object called an exception. This object contains properties and methods that describe the unexpected condition in detail and provide various items of useful information about what went wrong.

This chapter covers how structured exception handling works in Visual Basic. It discusses the common language runtime (CLR) exception handler in detail and illustrates some programming methods that are efficient when catching exceptions.