Export (0) Print
Expand All

Expression.Break Method (LabelTarget)

Creates a GotoExpression representing a break statement.

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

public static GotoExpression Break(
	LabelTarget target
)

Parameters

target
Type: System.Linq.Expressions.LabelTarget

The LabelTarget that the GotoExpression will jump to.

Return Value

Type: System.Linq.Expressions.GotoExpression
A GotoExpression with Kind equal to Break, the Target property set to target, and a null value to be passed to the target label upon jumping.

The following example demonstrates how to create an expression that contains a LoopExpression object that uses the Break method.

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

// Creating a parameter expression.
ParameterExpression value = Expression.Parameter(typeof(int), "value");

// Creating an expression to hold a local variable. 
ParameterExpression result = Expression.Parameter(typeof(int), "result");

// Creating a label to jump to from a loop.
LabelTarget label = Expression.Label(typeof(int));

// Creating a method body.
BlockExpression block = Expression.Block(
    new[] { result },
    Expression.Assign(result, Expression.Constant(1)),
        Expression.Loop(
           Expression.IfThenElse(
               Expression.GreaterThan(value, Expression.Constant(1)),
               Expression.MultiplyAssign(result,
                   Expression.PostDecrementAssign(value)),
               Expression.Break(label, result)
           ),
       label
    )
);

// Compile and run an expression tree. 
int factorial = Expression.Lambda<Func<int, int>>(block, value).Compile()(5);

Console.WriteLine(factorial);

// This code example produces the following output: 
// 
// 120

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

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

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.

Show:
© 2014 Microsoft