Expression.Goto 方法

定義

命名空間:

System.Linq.Expressions

組件:

System.Linq.Expressions.dll

建立表示 "go to" 陳述式的 GotoExpression。

多載

Goto(LabelTarget, Expression, Type)	建立 GotoExpression，表示含指定之類型的 "go to" 陳述式。 可以指定跳躍時傳遞至標籤的值。
Goto(LabelTarget, Type)	建立 GotoExpression，表示含指定之類型的 "go to" 陳述式。
Goto(LabelTarget)	建立表示 "go to" 陳述式的 GotoExpression。
Goto(LabelTarget, Expression)	建立表示 "go to" 陳述式的 GotoExpression。 可以指定跳躍時傳遞至標籤的值。

Goto(LabelTarget, Expression, Type)

來源:

GotoExpression.cs

建立 GotoExpression，表示含指定之類型的 "go to" 陳述式。 可以指定跳躍時傳遞至標籤的值。

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

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

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

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

參數

target

LabelTarget

LabelTarget 將跳躍的目標 GotoExpression。

value

Expression

將在跳躍時傳遞至關聯標籤的值。

type

Type

要將 Type 屬性設定為與之相等的 Type。

傳回

GotoExpression

GotoExpression，其 Kind 等於 Goto、Target 屬性設定為 target、Type 屬性設定為 type，且包含在跳躍時傳遞至目標標籤的 value。

Goto(LabelTarget, Type)

來源:

GotoExpression.cs

建立 GotoExpression，表示含指定之類型的 "go to" 陳述式。

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

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

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

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

參數

target

LabelTarget

LabelTarget 將跳躍的目標 GotoExpression。

type

Type

要將 Type 屬性設定為與之相等的 Type。

傳回

GotoExpression

GotoExpression，其 Kind 等於 Goto、Target 屬性設定為指定的值、Type 屬性設定為 type，且包含在跳躍時傳遞至目標標籤的 Null 值。

Goto(LabelTarget)

來源:

GotoExpression.cs

建立表示 "go to" 陳述式的 GotoExpression。

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

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

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

Public Shared Function Goto (target As LabelTarget) As GotoExpression

參數

target

LabelTarget

LabelTarget 將跳躍的目標 GotoExpression。

傳回

GotoExpression

GotoExpression，其 Kind 等於 Goto、Target 屬性設定為指定的值，且包含在跳躍時傳遞至目標標籤的 Null 值。

範例

下列範例示範如何建立包含 GotoExpression 對象的表達式。

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

// A label expression of the void type that is the target for the GotoExpression.
LabelTarget returnTarget = Expression.Label();

// This block contains a GotoExpression.
// It transfers execution to a label expression that is initialized with the same LabelTarget as the GotoExpression.
// The types of the GotoExpression, label expression, and LabelTarget must match.
BlockExpression blockExpr =
    Expression.Block(
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("GoTo")),
        Expression.Goto(returnTarget),
        Expression.Call(typeof(Console).GetMethod("WriteLine", new Type[] { typeof(string) }), Expression.Constant("Other Work")),
        Expression.Label(returnTarget)
    );

// The following statement first creates an expression tree,
// then compiles it, and then runs it.
Expression.Lambda<Action>(blockExpr).Compile()();

// This code example produces the following output:
//
// GoTo

// "Other Work" is not printed because
// the GoTo expression transfers execution from Expression.GoTo(returnTarget)
// to Expression.Label(returnTarget).

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

' A label expression of the void type that is the target for the GoToExpression.
Dim returnTarget As LabelTarget = Expression.Label()

' This block contains a GotoExpression.
' It transfers execution to a label expression that is initialized with the same LabelTarget as the GotoExpression.
' The types of the GotoExpression, label expression, and LabelTarget must match.
Dim blockExpr As BlockExpression =
      Expression.Block(
          Expression.Call(GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}), Expression.Constant("GoTo")),
          Expression.Goto(returnTarget),
          Expression.Call(GetType(Console).GetMethod("WriteLine", New Type() {GetType(String)}), Expression.Constant("Other Work")),
          Expression.Label(returnTarget)
      )

' The following statement first creates an expression tree,
' then compiles it, and then runs it.
Expression.Lambda(Of Action)(blockExpr).Compile()()

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

' "Other Work" is not printed because 
' the Return expression transfers execution from Expression.GoTo(returnTarget)
' to Expression.Label(returnTarget).

Goto(LabelTarget, Expression)

來源:

GotoExpression.cs

建立表示 "go to" 陳述式的 GotoExpression。 可以指定跳躍時傳遞至標籤的值。

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

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

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

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

參數

target

LabelTarget

LabelTarget 將跳躍的目標 GotoExpression。

value

Expression

將在跳躍時傳遞至關聯標籤的值。

傳回

GotoExpression

GotoExpression，其 Kind 等於 Goto、Target 屬性設定為 target，且，且包含在跳躍時傳遞至目標標籤的 value。