Creating and Throwing Exceptions

Learn how to define custom exception classes with specific properties and throw them to handle application-specific errors.

We'll cover the following...

Defining a custom exception
Adding custom data
Throwing exceptions
Rethrowing best practices
Exception filters

Although .NET provides many built-in exception types, applications often require specific error handling for domain-specific scenarios. Developers handle these scenarios by creating custom exceptions.

Note: To create a custom exception, we define a class that inherits from the System.Exception class or one of its derived classes.

Defining a custom exception

Consider a login feature that validates a username and password. If the credentials are invalid, we should throw an exception that explicitly states the failure reason rather than a generic error.

We start by inheriting from the base Exception class.