本文整理匯總了VB.NET中System.Linq.Expressions.Expression.Call方法的典型用法代碼示例。如果您正苦於以下問題：VB.NET Expression.Call方法的具體用法？VB.NET Expression.Call怎麽用？VB.NET Expression.Call使用的例子？那麽, 這裏精選的方法代碼示例或許可以為您提供幫助。您也可以進一步了解該方法所在類System.Linq.Expressions.Expression的用法示例。
在下文中一共展示了Expression.Call方法的3個代碼示例，這些例子默認根據受歡迎程度排序。您可以為喜歡或者感覺有用的代碼點讚，您的評價將有助於係統推薦出更棒的VB.NET代碼示例。
示例1: SampleClass
' Add the following directive to your file:
' Imports System.Linq.Expressions
Public Class SampleClass
Public Function AddIntegers(ByVal arg1 As Integer, ByVal arg2 As Integer) As Integer
Return (arg1 + arg2)
End Function
End Class
Public Shared Sub TestCall()
' This expression represents a call to an instance method that has two arguments.
' The first argument is an expression that creates a new object of the specified type.
Dim callExpr As Expression = Expression.Call(
Expression.[New](GetType(SampleClass)),
GetType(SampleClass).GetMethod("AddIntegers", New Type() {GetType(Integer), GetType(Integer)}),
Expression.Constant(1),
Expression.Constant(2)
)
' Print the expression.
Console.WriteLine(callExpr.ToString())
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
Console.WriteLine(Expression.Lambda(Of Func(Of Integer))(callExpr).Compile()())
End Sub輸出：
new SampleClass().AddIntegers(1, 2) 3
示例2: SampleClass
' Add the following directive to your file:
' Imports System.Linq.Expressions
Public Class SampleClass
Shared Function Increment(ByVal arg1 As Integer) As Integer
Return arg1 + 1
End Function
End Class
Shared Sub TestCall()
'This expression represents a call to an instance method with one argument.
Dim callExpr As Expression = Expression.Call(
GetType(SampleClass).GetMethod("Increment"),
Expression.Constant(2))
' Print the expression.
Console.WriteLine(callExpr.ToString())
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
Console.WriteLine(Expression.Lambda(Of Func(Of Integer))(callExpr).Compile()())
End Sub輸出：
Increment(2) 3
示例3: GetType
' Add the following directive to your file:
' Imports System.Linq.Expressions
' This expression represents a call to an instance method without arguments.
Dim callExpr As Expression = Expression.Call(
Expression.Constant("sample string"), GetType(String).GetMethod("ToUpper", New Type() {}))
' Print the expression.
Console.WriteLine(callExpr.ToString())
' The following statement first creates an expression tree,
' then compiles it, and then executes it.
Console.WriteLine(Expression.Lambda(Of Func(Of String))(callExpr).Compile()())輸出：
"sample string".ToUpper SAMPLE STRING