Expression.Loop Método

Definición

Espacio de nombres:

System.Linq.Expressions

Ensamblado:

System.Linq.Expressions.dll

Crea una interfaz LoopExpression.

Sobrecargas

Loop(Expression)	Crea un objeto LoopExpression con el cuerpo especificado.
Loop(Expression, LabelTarget)	Crea un objeto LoopExpression con el cuerpo especificado y el destino de Break.
Loop(Expression, LabelTarget, LabelTarget)	Crea un objeto LoopExpression con el cuerpo especificado.

Loop(Expression)

Source:

LoopExpression.cs

Crea un objeto LoopExpression con el cuerpo especificado.

public:
 static System::Linq::Expressions::LoopExpression ^ Loop(System::Linq::Expressions::Expression ^ body);

public static System.Linq.Expressions.LoopExpression Loop (System.Linq.Expressions.Expression body);

static member Loop : System.Linq.Expressions.Expression -> System.Linq.Expressions.LoopExpression

Public Shared Function Loop (body As Expression) As LoopExpression

Parámetros

body

Expression

Cuerpo del bucle.

Devoluciones

LoopExpression

Objeto LoopExpression creado.

Loop(Expression, LabelTarget)

Source:

LoopExpression.cs

Crea un objeto LoopExpression con el cuerpo especificado y el destino de Break.

public:
 static System::Linq::Expressions::LoopExpression ^ Loop(System::Linq::Expressions::Expression ^ body, System::Linq::Expressions::LabelTarget ^ break);

public static System.Linq.Expressions.LoopExpression Loop (System.Linq.Expressions.Expression body, System.Linq.Expressions.LabelTarget? break);

static member Loop : System.Linq.Expressions.Expression * System.Linq.Expressions.LabelTarget -> System.Linq.Expressions.LoopExpression

Public Shared Function Loop (body As Expression, break As LabelTarget) As LoopExpression

Parámetros

body

Expression

Cuerpo del bucle.

break

LabelTarget

Destino Break empleado por el cuerpo del bucle.

Devoluciones

LoopExpression

Objeto LoopExpression creado.

Ejemplos

En el ejemplo siguiente se muestra cómo crear una expresión de bloque que contiene un LoopExpression objeto .

// 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

Loop(Expression, LabelTarget, LabelTarget)

Source:

LoopExpression.cs

Crea un objeto LoopExpression con el cuerpo especificado.

public:
 static System::Linq::Expressions::LoopExpression ^ Loop(System::Linq::Expressions::Expression ^ body, System::Linq::Expressions::LabelTarget ^ break, System::Linq::Expressions::LabelTarget ^ continue);

public static System.Linq.Expressions.LoopExpression Loop (System.Linq.Expressions.Expression body, System.Linq.Expressions.LabelTarget? break, System.Linq.Expressions.LabelTarget? continue);

static member Loop : System.Linq.Expressions.Expression * System.Linq.Expressions.LabelTarget * System.Linq.Expressions.LabelTarget -> System.Linq.Expressions.LoopExpression

Public Shared Function Loop (body As Expression, break As LabelTarget, continue As LabelTarget) As LoopExpression

Parámetros

body

Expression

Cuerpo del bucle.

break

LabelTarget

Destino Break empleado por el cuerpo del bucle.

continue

LabelTarget

Destino Continue empleado por el cuerpo del bucle.

Devoluciones

LoopExpression

Objeto LoopExpression creado.