Expression.Break Méthode

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

Paramètres

Retours

Kind Égal GotoExpression à Break, la Target propriété définie sur target, et une valeur Null à passer à l’étiquette cible lors du saut.

Exemples

L’exemple suivant montre comment créer une expression qui contient un LoopExpression objet qui utilise la Break méthode.

// 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

Paramètres

Retours

Kind Égal GotoExpression à Break, la Target propriété définie targetsur , et value à passer à l’étiquette cible lors du saut.

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

Paramètres

Retours

Égal GotoExpression à Break, la Target propriété définie targetsur , et la Type propriété définie sur type.Kind

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

Paramètres

Retours

Kind Égal GotoExpression à Break, la Target propriété définie targetsur , la Type propriété définie typesur et value à passer à l’étiquette cible lors du saut.