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CallerMemberNameAttribute Class

.NET Framework 4.5

Allows you to obtain the method or property name of the caller to the method.

System.Object
  System.Attribute
    System.Runtime.CompilerServices.CallerMemberNameAttribute

Namespace:  System.Runtime.CompilerServices
Assembly:  mscorlib (in mscorlib.dll)

[AttributeUsageAttribute(AttributeTargets.Parameter, Inherited = false)]
public sealed class CallerMemberNameAttribute : Attribute

The CallerMemberNameAttribute type exposes the following members.

  NameDescription
Public methodSupported in .NET for Windows Store appsCallerMemberNameAttributeInitializes a new instance of the CallerMemberNameAttribute class.
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  NameDescription
Public propertyTypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)
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  NameDescription
Public methodSupported in .NET for Windows Store appsEqualsInfrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Public methodSupported in .NET for Windows Store appsGetHashCodeReturns the hash code for this instance. (Inherited from Attribute.)
Public methodSupported in .NET for Windows Store appsGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodIsDefaultAttributeWhen overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
Public methodMatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Public methodSupported in .NET for Windows Store appsToStringReturns a string that represents the current object. (Inherited from Object.)
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  NameDescription
Explicit interface implemetationPrivate method_Attribute.GetIDsOfNamesMaps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoRetrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.GetTypeInfoCountRetrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetationPrivate method_Attribute.InvokeProvides access to properties and methods exposed by an object. (Inherited from Attribute.)
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You apply the CallerMemberName attribute to an optional parameter that has a default value. You must specify an explicit default value for the optional parameter. You can't apply this attribute to parameters that aren't specified as optional.

For more information, see Caller Information (C# and Visual Basic).

You can use the CallerMemberName attribute to avoid specifying the member name as a String argument to the called method. By using this technique, you avoid the problem that Rename Refactoring doesn't change the String values. This is especially useful for the following tasks:

  • Using tracing and diagnostic routines.

  • Implementing the INotifyPropertyChanged interface when binding data. This interface allows the property of an object to notify a bound control that the property has changed, so that the control can display the updated information. Without the CallerMemberName attribute, you must specify the property name as a literal.

The following chart shows the member names that are returned when you use the CallerMemberName attribute.

Call occurs within

Member name result

Method, property, or event

The name of the method, property, or event from which the call originated.

Constructor

The string ".ctor"

Static constructor

The string ".cctor"

Destructor

The string "Finalize"

User-defined operators or conversions

The generated name for the member, for example, "op_Addition".

Attribute constructor

The name of the member to which the attribute is applied. If the attribute is any element within a member (such as a parameter, a return value, or a generic type parameter), this result is the name of the member that's associated with that element.

No containing member (for example, assembly-level or attributes applied to types)

The default value of the optional parameter.

The following example shows how to use the CallerMemberName attribute. On each call to the TraceMessage method, the caller information is substituted as an argument to the optional parameter.

// using System.Runtime.CompilerServices 
// using System.Diagnostics; 

public void DoProcessing()
{
    TraceMessage("Something happened.");
}

public void TraceMessage(string message,
        [CallerMemberName] string memberName = "",
        [CallerFilePath] string sourceFilePath = "",
        [CallerLineNumber] int sourceLineNumber = 0)
{
    Trace.WriteLine("message: " + message);
    Trace.WriteLine("member name: " + memberName);
    Trace.WriteLine("source file path: " + sourceFilePath);
    Trace.WriteLine("source line number: " + sourceLineNumber);
}

// Sample Output: 
//  message: Something happened. 
//  member name: DoProcessing 
//  source file path: c:\Users\username\Documents\Visual Studio 2012\Projects\CallerInfoCS\CallerInfoCS\Form1.cs 
//  source line number: 31

.NET Framework

Supported in: 4.5

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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