Label Method

Expression.Label Method ()


Creates a LabelTarget representing a label with void type and no name.

Namespace:   System.Linq.Expressions
Assembly:  System.Core (in System.Core.dll)

public static LabelTarget Label()

The following example demonstrates how to create an expression that contains a LabelTarget object.

// Add the following directive to the file:
// using System.Linq.Expressions;  

// A label expression of the void type that is the target for Expression.Return().
LabelTarget returnTarget = Expression.Label();

// This block contains a GotoExpression that represents a return statement with no value.
// It transfers execution to a label expression that is initialized with the same LabelTarget as the GotoExpression.
// The types of the GotoExpression, label expression, and LabelTarget must match.
BlockExpression blockExpr =
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Return")),
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Other Work")),

// The following statement first creates an expression tree,
// then compiles it, and then runs it.

// This code example produces the following output:
// Return

// "Other Work" is not printed because 
// the Return expression transfers execution from Expression.Return(returnTarget)
// to Expression.Label(returnTarget).

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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