VB.NET函数以字符串形式获取属性名称 [英] VB.NET function get property name as string

问题描述

我正在尝试创建一个函数，当将属性作为参数传递给它时，它返回用于将属性定义为字符串的名称.例如

I'm trying to create a function that when a property is passed to it as a parameter, it returns the name used to define the property as a string. For example,

Shared Function PropertyToStr(Propert As Object)
     'Code to get property name and return it as a string goes here  
End Function

提供First_Name是属性的名称，定义如下:

Providing that First_Name is a the name of a property, defined like:

Property First_Name as String

该功能应类似于:

Dim str as String = PropertyToStr(First_Name) ' Resulting in str = "First_Name"

请注意，我只希望在此函数中返回属性名称"First_Name"，而不是例如"MyClass.First_Name".

Note I ONLY want in this function to return the property name "First_Name", and not "MyClass.First_Name" for example.

我发现了其他一些与我的函数相似的代码示例，我需要用c#编写，但是我无法在VB.Net中复制它们对MemberExpression的使用

I have found other examples of similar code to my function I require written in c# yet I have not been able to replicate their use of the MemberExpression in VB.Net

获取强类型的子属性名称

以字符串形式获取属性名称

从lambda表达式中检索属性名称

推荐答案

在Visual Studio 2015中，您可以使用NameOf运算符来完成此操作:

In Visual Studio 2015 you can use the NameOf operator to accomplish this:

Property First_Name As String

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    MessageBox.Show(NameOf(First_Name))
End Sub

.net早期版本的原始答案:

Original answer for older versions of .net:

通过一些代码转换器运行其他答案并清理它会产生以下效果，看来效果很好.

Running those other answers through some code converters and cleaning it up yields the following, which seems to work just fine.

Private Shared Function GetMemberInfo(method As Expression) As MemberExpression
    Dim lambda As LambdaExpression = TryCast(method, LambdaExpression)
    If lambda Is Nothing Then
        Throw New ArgumentNullException("method")
    End If

    Dim memberExpr As MemberExpression = Nothing

    If lambda.Body.NodeType = ExpressionType.Convert Then
        memberExpr = TryCast(DirectCast(lambda.Body, UnaryExpression).Operand, MemberExpression)
    ElseIf lambda.Body.NodeType = ExpressionType.MemberAccess Then
        memberExpr = TryCast(lambda.Body, MemberExpression)
    End If

    If memberExpr Is Nothing Then
        Throw New ArgumentException("method")
    End If

    Return memberExpr
End Function

Public Shared Function GetPropertyName(Of T)(prop As Expression(Of Func(Of T))) As String
    Dim expression = GetMemberInfo(prop)
    Return expression.Member.Name
End Function

Property First_Name As String
Property LastName As String
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    MessageBox.Show(GetPropertyName(Function() First_Name))
    MessageBox.Show(GetPropertyName(Function() LastName))
End Sub

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