_Strategies to Get Rid of NullReferenceException.png

dotnet6.tar.gz

dotnet6job

NullReferenceException is an error that programmers frequently encounter, and it is often referred to as the Billion Dollar Mistake. This course is designed to assist you in avoiding this error.

You will begin by gaining an understanding of when NullReferenceException is thrown and how to prevent null in your code. You’ll also learn how to employ nullable operators to simplify null checks and use nullable references and the Option wrapper to identify problematic code blocks. Finally, you will explore avoiding NullReferenceException when using specific LINQ methods and designing your C# classes.

Upon completing this course, you’ll have gained the necessary knowledge and skills to effectively address and avoid NullReferenceException issues in your projects.

Mastering NullReferenceException Prevention in C#

# Update a configuration object

For this exercise, let's stop talking about movies. This is a slightly modified version of a real `NullReferenceException` issue from an open-source content management project.

Imagine that inside our web application, we have a "Setup" page where we can change some security parameters when installing our application from scratch, like the maximum size of parameters in URLs and the size of files to be uploaded.

The `SetMaxUploadSize()` method changes the maximum size of files to upload to our application. But it's breaking with a `NullReferenceException`.

To complete this exercise, feel free to use any technique covered in this minicourse to fix the `NullReferenceException`.

Solve a real NullReferenceException issue when updating a configuration object.

Exercise: Solve a Real NullReferenceException Issue

Update a configuration object