Expression.Loop Yöntem

Tanım

Ad Alanı:

System.Linq.Expressions

Bütünleştirilmiş Kod:

System.Linq.Expressions.dll

bir LoopExpressionoluşturur.

Aşırı Yüklemeler

Loop(Expression)	Verilen gövde ile bir LoopExpression oluşturur.
Loop(Expression, LabelTarget)	Verilen gövde ile bir LoopExpression oluşturur ve hedefi kırar.
Loop(Expression, LabelTarget, LabelTarget)	Verilen gövde ile bir LoopExpression oluşturur.

Loop(Expression)

Kaynak:

LoopExpression.cs

Verilen gövde ile bir LoopExpression oluşturur.

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

Parametreler

body

Expression

Döngünün gövdesi.

Döndürülenler

LoopExpression

Oluşturulan LoopExpression.

Loop(Expression, LabelTarget)

Kaynak:

LoopExpression.cs

Verilen gövde ile bir LoopExpression oluşturur ve hedefi kırar.

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

Parametreler

body

Expression

Döngünün gövdesi.

break

LabelTarget

Döngü gövdesi tarafından kullanılan kesme hedefi.

Döndürülenler

LoopExpression

Oluşturulan LoopExpression.

Örnekler

Aşağıdaki örnekte, nesne içeren LoopExpression bir blok ifadesinin nasıl oluşturulacağı gösterilmektedir.

// 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)

Kaynak:

LoopExpression.cs

Verilen gövde ile bir LoopExpression oluşturur.

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

Parametreler

body

Expression

Döngünün gövdesi.

break

LabelTarget

Döngü gövdesi tarafından kullanılan kesme hedefi.

continue

LabelTarget

Döngü gövdesi tarafından kullanılan devam hedefi.

Döndürülenler

LoopExpression

Oluşturulan LoopExpression.