VB.NET Expression.AddAssign方法代码示例

OStack程序员社区-中国程序员成长平台 › 门户 › 编程› VB.NET›VB.NET教程

原作者: [db:作者] 来自: [db:来源] 收藏邀请

本文整理汇总了VB.NET中System.Linq.Expressions.Expression.AddAssign方法的典型用法代码示例。如果您正苦于以下问题：VB.NET Expression.AddAssign方法的具体用法？VB.NET Expression.AddAssign怎么用？VB.NET Expression.AddAssign使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类System.Linq.Expressions.Expression的用法示例。

在下文中一共展示了Expression.AddAssign方法的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，您的评价将有助于我们的系统推荐出更棒的VB.NET代码示例。

示例1: ParameterExpression

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

' The parameter expression is used to create a variable.
Dim variableExpr As ParameterExpression = Expression.Variable(GetType(Integer), "sampleVar")

' The block expression enables you to execute several expressions sequentually.
' In this block, the variable is first initialized with 1. 
' Then the AddAssign method adds 2 to the variable and assigns the result to the variable.
Dim addAssignExpr As BlockExpression = Expression.Block(
    New ParameterExpression() {variableExpr},
    Expression.Assign(variableExpr, Expression.Constant(1)),
    Expression.AddAssign(
        variableExpr,
        Expression.Constant(2)
    )
)

' Print the expression from the block expression.
Console.WriteLine("The expressions from the block expression:")
For Each expr As Expression In addAssignExpr.Expressions
    Console.WriteLine(expr.ToString())
Next

Console.WriteLine("The result of executing the expression tree:")
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
Console.WriteLine(Expression.Lambda(Of Func(Of Integer))(addAssignExpr).Compile()())

开发者ID:VB.NET开发者，项目名称:System.Linq.Expressions，代码行数:28，代码来源:Expression.AddAssign

输出：

The expressions from the block expression:
(sampleVar = 1)
(sampleVar += 2)

The result of executing the expression tree:
3

注：本文中的System.Linq.Expressions.Expression.AddAssign方法示例由纯净天空整理自Github/MSDocs等源码及文档管理平台，相关代码片段筛选自各路编程大神贡献的开源项目，源码版权归原作者所有，传播和使用请参考对应项目的License；未经允许，请勿转载。