本文整理汇总了VB.NET中System.Linq.Expressions.LabelTarget类的典型用法代码示例。如果您正苦于以下问题:VB.NET LabelTarget类的具体用法?VB.NET LabelTarget怎么用?VB.NET LabelTarget使用的例子?那么恭喜您, 这里精选的类代码示例或许可以为您提供帮助。
在下文中一共展示了LabelTarget类的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的VB.NET代码示例。
示例1: Type
' Add the following directive to the file:
' Imports System.Linq.Expressions
' A label expression of the void type that is the target for Expression.Return().
Dim returnTarget As LabelTarget = Expression.Label()
' This block contains a GotoExpression that represents a return statement with no value.
' 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("Return")),
Expression.Return(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()()
输出:
Return "Other Work" is not printed because the Return expression transfers execution from Return(returnTarget) to Expression.Label(returnTarget).