Expression.Break Methode

public:
 static System::Linq::Expressions::GotoExpression ^ Break(System::Linq::Expressions::LabelTarget ^ target);

public static System.Linq.Expressions.GotoExpression Break(System.Linq.Expressions.LabelTarget target);

static member Break : System.Linq.Expressions.LabelTarget -> System.Linq.Expressions.GotoExpression

Public Shared Function Break (target As LabelTarget) As GotoExpression

Parameters

Retouren

Een GotoExpression met Kind gelijk aan Einde, de Target eigenschap ingesteld op targeten een null-waarde die moet worden doorgegeven aan het doellabel bij het springen.

Voorbeelden

In het volgende voorbeeld ziet u hoe u een expressie maakt die een LoopExpression object bevat dat gebruikmaakt van de Break methode.

// 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

' Add the following directive to the file:
' Imports System.Linq.Expressions  

' Creating a parameter expression.
Dim value As ParameterExpression =
    Expression.Parameter(GetType(Integer), "value")

' Creating an expression to hold a local variable. 
Dim result As ParameterExpression =
    Expression.Parameter(GetType(Integer), "result")

' Creating a label to jump to from a loop.
Dim label As LabelTarget = Expression.Label(GetType(Integer))

' Creating a method body.
Dim block As BlockExpression = Expression.Block(
    New ParameterExpression() {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 an expression tree and return a delegate.
Dim factorial As Integer =
    Expression.Lambda(Of Func(Of Integer, Integer))(block, value).Compile()(5)

Console.WriteLine(factorial)

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

public:
 static System::Linq::Expressions::GotoExpression ^ Break(System::Linq::Expressions::LabelTarget ^ target, System::Linq::Expressions::Expression ^ value);

public static System.Linq.Expressions.GotoExpression Break(System.Linq.Expressions.LabelTarget target, System.Linq.Expressions.Expression value);

static member Break : System.Linq.Expressions.LabelTarget * System.Linq.Expressions.Expression -> System.Linq.Expressions.GotoExpression

Public Shared Function Break (target As LabelTarget, value As Expression) As GotoExpression

Parameters

Retouren

Een GotoExpression met Kind gelijk aan Break, de Target eigenschap is ingesteld op targeten value moet worden doorgegeven aan het doellabel bij het springen.

public:
 static System::Linq::Expressions::GotoExpression ^ Break(System::Linq::Expressions::LabelTarget ^ target, Type ^ type);

public static System.Linq.Expressions.GotoExpression Break(System.Linq.Expressions.LabelTarget target, Type type);

static member Break : System.Linq.Expressions.LabelTarget * Type -> System.Linq.Expressions.GotoExpression

Public Shared Function Break (target As LabelTarget, type As Type) As GotoExpression

Parameters

Retouren

A GotoExpression met Kind gelijk aan Einde, de Target eigenschap ingesteld op targeten de Type eigenschap ingesteld op type.

public:
 static System::Linq::Expressions::GotoExpression ^ Break(System::Linq::Expressions::LabelTarget ^ target, System::Linq::Expressions::Expression ^ value, Type ^ type);

public static System.Linq.Expressions.GotoExpression Break(System.Linq.Expressions.LabelTarget target, System.Linq.Expressions.Expression value, Type type);

static member Break : System.Linq.Expressions.LabelTarget * System.Linq.Expressions.Expression * Type -> System.Linq.Expressions.GotoExpression

Public Shared Function Break (target As LabelTarget, value As Expression, type As Type) As GotoExpression

Parameters

Retouren

Een GotoExpression met Kind gelijk aan Break, de Target eigenschap ingesteld op target, de Type eigenschap ingesteld op typeen value moet worden doorgegeven aan het doellabel bij het springen.