本文整理汇总了VB.NET中System.Linq.Expressions.Expression.ArrayAccess方法的典型用法代码示例。如果您正苦于以下问题：VB.NET Expression.ArrayAccess方法的具体用法？VB.NET Expression.ArrayAccess怎么用？VB.NET Expression.ArrayAccess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.ArrayAccess方法的2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: List
' Add the following directive to your file:
' Imports System.Linq.Expressions
' This parameter expression represents a variable that will hold the two-dimensional array.
Dim arrayExpr As ParameterExpression = Expression.Parameter(GetType(Integer(,)), "Array")
' This parameter expression represents a first array index.
Dim firstIndexExpr As ParameterExpression = Expression.Parameter(GetType(Integer), "FirstIndex")
' This parameter expression represents a second array index.
Dim secondIndexExpr As ParameterExpression = Expression.Parameter(GetType(Integer), "SecondIndex")
' The list of indexes.
Dim indexes As List(Of Expression) = New List(Of Expression) From
{firstIndexExpr, secondIndexExpr}
' This parameter represents the value that will be added to a corresponding array element.
Dim valueExpr As ParameterExpression = Expression.Parameter(GetType(Integer), "Value")
' This expression represents an access operation to a multidimensional array.
' It can be used for assigning to, or reading from, an array element.
Dim arrayAccessExpr As Expression = Expression.ArrayAccess(
arrayExpr,
indexes
)
' This lambda expression assigns a value provided to it to a specified array element.
' The array, the index of the array element, and the value to be added to the element
' are parameters of the lambda expression.
Dim lambdaExpr As Expression(Of Func(Of Integer(,), Integer, Integer, Integer, Integer)) =
Expression.Lambda(Of Func(Of Integer(,), Integer, Integer, Integer, Integer))(
Expression.Assign(arrayAccessExpr, Expression.Add(arrayAccessExpr, valueExpr)),
arrayExpr,
firstIndexExpr,
secondIndexExpr,
valueExpr
)
' Print expressions.
Console.WriteLine("Array Access Expression:")
Console.WriteLine(arrayAccessExpr.ToString())
Console.WriteLine("Lambda Expression:")
Console.WriteLine(lambdaExpr.ToString())
Console.WriteLine("The result of executing the lambda expression:")
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
' Parameters passed to the Invoke method are passed to the lambda expression.
Dim sampleArray = {{10, 20, 30},
{100, 200, 300}}
Console.WriteLine(lambdaExpr.Compile().Invoke(sampleArray, 1, 1, 5))输出：
Array Access Expression: Array[FirstIndex, SecondIndex] Lambda Expression: (Array, FirstIndex, SecondIndex Value) => (Array[FirstIndex, SecondIndex] = (Array[FirstIndex, SecondIndex] + Value)) The result of executing the lambda expression: 205
示例2: Expression
' Add the following directive to your file:
' Imports System.Linq.Expressions
' This parameter expression represents a variable that will hold the array.
Dim arrayExpr As ParameterExpression = Expression.Parameter(GetType(Integer()), "Array")
' This parameter expression represents an array index.
' For multidimensional arrays, you can define several indexes.
Dim indexExpr As ParameterExpression = Expression.Parameter(GetType(Integer), "Index")
' This parameter represents the value that will be added to a corresponding array element.
Dim valueExpr As ParameterExpression = Expression.Parameter(GetType(Integer), "Value")
' This expression represents an array access operation.
' It can be used for assigning to, or reading from, an array element.
Dim arrayAccessExpr As Expression = Expression.ArrayAccess(
arrayExpr,
indexExpr
)
' This lambda expression assigns a value provided to it to a specified array element.
' The array, the index of the array element, and the value to be added to the element
' are parameters of the lambda expression.
Dim lambdaExpr As Expression(Of Func(Of Integer(), Integer, Integer, Integer)) =
Expression.Lambda(Of Func(Of Integer(), Integer, Integer, Integer))(
Expression.Assign(arrayAccessExpr, Expression.Add(arrayAccessExpr, valueExpr)),
arrayExpr,
indexExpr,
valueExpr
)
' Print expressions.
Console.WriteLine("Array Access Expression:")
Console.WriteLine(arrayAccessExpr.ToString())
Console.WriteLine("Lambda Expression:")
Console.WriteLine(lambdaExpr.ToString())
Console.WriteLine("The result of executing the lambda expression:")
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
' Parameters passed to the Invoke method are passed to the lambda expression.
Console.WriteLine(lambdaExpr.Compile().Invoke(New Integer() {10, 20, 30}, 0, 5))输出：
Array Access Expression: Array[Index] Lambda Expression: (Array, Index, Value) => (Array[Index] = (Array[Index] + Value)) The result of executing the lambda expression: 15