CallerMemberName

CallerMemberName is an attribute in the .NET framework and .NET Core defined in System.Runtime.CompilerServices. It enables a parameter to automatically receive the name of the caller member, simplifying scenarios such as implementing INotifyPropertyChanged and reducing reliance on hard-coded strings.

Usage typically involves applying the attribute to an optional string parameter, usually named propertyName, with a default value of null. When the parameter is omitted by the caller, the compiler substitutes the name of the calling member. For example: OnPropertyChanged([CallerMemberName] string propertyName = null) { ... }. Calling OnPropertyChanged() from inside a property setter will supply the property’s name automatically.

Notes and behavior: The automatic substitution occurs only when the parameter is omitted; explicitly passing a value overrides the automatic result. The feature is most useful for property and method names within the same project and language. It is commonly used to raise property change notifications without using literal strings, thereby aiding refactoring and maintenance.

Related attributes include CallerLineNumber and CallerFilePath, which capture the caller’s line number and source file path, respectively. Together, these attributes provide lightweight metadata about call sites to support cleaner and more maintainable code.