NullableContextAttribute

NullableContextAttribute is a class in the System.Runtime.CompilerServices namespace of the .NET Framework. It is used to control the behavior of nullable reference types in C#. Nullable reference types are a feature introduced in C# 8.0 that allows developers to specify whether a reference type can be null or not, thereby enhancing code safety and reducing the likelihood of null reference exceptions.

The NullableContextAttribute class is typically used in conjunction with the NullableAttribute class. It provides a way to specify the default nullability context for a given assembly or module. This context can be either enabled or disabled, and it determines whether reference types are considered nullable by default.

When the NullableContextAttribute is applied to an assembly or module, it sets the default nullability context for all types within that scope. This can be overridden on a per-type or per-member basis using the NullableAttribute class. The attribute takes a single parameter, which is a byte value that specifies the nullability context. A value of 1 indicates that the context is enabled, while a value of 2 indicates that it is disabled.

NullableContextAttribute is particularly useful in large codebases where maintaining consistent nullability annotations can be challenging. By setting a default nullability context, developers can ensure that their code adheres to a consistent nullability policy, reducing the need for repetitive annotations and minimizing the risk of null reference exceptions.