Expression.Continue 方法

定义

创建一个 GotoExpression 表示 continue 语句。

重载

名称 说明
Continue(LabelTarget)

创建一个 GotoExpression 表示 continue 语句。

Continue(LabelTarget, Type)

创建一个 GotoExpression 表示具有指定类型的 continue 语句。

Continue(LabelTarget)

创建一个 GotoExpression 表示 continue 语句。

public:
 static System::Linq::Expressions::GotoExpression ^ Continue(System::Linq::Expressions::LabelTarget ^ target);
public static System.Linq.Expressions.GotoExpression Continue(System.Linq.Expressions.LabelTarget target);
static member Continue : System.Linq.Expressions.LabelTarget -> System.Linq.Expressions.GotoExpression
Public Shared Function Continue (target As LabelTarget) As GotoExpression

参数

target
LabelTarget

LabelTarget 跳到的 GotoExpression 那个。

返回

KindGotoExpression等于 Continue、属性Target设置为 target 和一个 null 值,在跳转时传递给目标标签。

示例

以下示例演示如何创建使用该 Continue 方法的循环表达式。

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

// A label that is used by a break statement and a loop.
LabelTarget breakLabel = Expression.Label();

// A label that is used by the Continue statement and the loop it refers to.
LabelTarget continueLabel = Expression.Label();

// This expression represents a Continue statement.
Expression continueExpr = Expression.Continue(continueLabel);

// A variable that triggers the exit from the loop.
ParameterExpression count = Expression.Parameter(typeof(int));

// A loop statement.
Expression loopExpr = Expression.Loop(
    Expression.Block(
        Expression.IfThen(
            Expression.GreaterThan(count, Expression.Constant(3)),
            Expression.Break(breakLabel)
        ),
        Expression.PreIncrementAssign(count),
        Expression.Call(
                    null,
                    typeof(Console).GetMethod("WriteLine", new Type[] { typeof(String) }),
                    Expression.Constant("Loop")
                ),
        continueExpr,
        Expression.PreDecrementAssign(count)
    ),
    breakLabel,
    continueLabel
);

// The following statement first creates an expression tree,
// then compiles it, and then runs it.
// Without the Continue statement, the loop would go on forever.
Expression.Lambda<Action<int>>(loopExpr, count).Compile()(1);

// This code example produces the following output:
//
// Loop
// Loop
// Loop
' Add the following directive to your file:
' Imports System.Linq.Expressions  

' A label that is used by a break statement and a loop. 
Dim breakLabel As LabelTarget = Expression.Label()

' A label that is used by the Continue statement and the loop it refers to.
Dim continueLabel As LabelTarget = Expression.Label()

' This expression represents a Continue statement.
Dim continueExpr As Expression = Expression.Continue(continueLabel)

' A variable that triggers the exit from the loop.
Dim count As ParameterExpression = Expression.Parameter(GetType(Integer))

' A loop statement.
Dim loopExpr As Expression = Expression.Loop(
       Expression.Block(
           Expression.IfThen(
               Expression.GreaterThan(count, Expression.Constant(3)),
               Expression.Break(breakLabel)
           ),
           Expression.PreIncrementAssign(count),
           Expression.Call(
                       Nothing,
                       GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}),
                       Expression.Constant("Loop")
                   ),
           continueExpr,
           Expression.PreDecrementAssign(count)
       ),
       breakLabel,
       continueLabel
   )

' The following statement first creates an expression tree,
' then compiles it, and then runs it.
' Without the Continue statement, the loop would go on forever.
Expression.Lambda(Of Action(Of Integer))(loopExpr, count).Compile()(1)

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

适用于

Continue(LabelTarget, Type)

创建一个 GotoExpression 表示具有指定类型的 continue 语句。

public:
 static System::Linq::Expressions::GotoExpression ^ Continue(System::Linq::Expressions::LabelTarget ^ target, Type ^ type);
public static System.Linq.Expressions.GotoExpression Continue(System.Linq.Expressions.LabelTarget target, Type type);
static member Continue : System.Linq.Expressions.LabelTarget * Type -> System.Linq.Expressions.GotoExpression
Public Shared Function Continue (target As LabelTarget, type As Type) As GotoExpression

参数

target
LabelTarget

LabelTarget 跳到的 GotoExpression 那个。

type
Type

要设置的属性Type等于的一个Type

返回

等于 Continue、属性设置为 <a0/> 的属性设置为 ,以及跳转时要传递给目标标签的 null 值。

适用于