7

我第一次深入研究反射，我真的被困住了。我用谷歌搜索了我能想到的一切。我现在想去的地方有 90%。

我正在尝试通过反射返回自定义类中的属性值。

这是我的班级声明：

Public Class Class2
    Private newPropertyValue2 As String

    Public Property NewProperty2() As String
        Get
            Return newPropertyValue2
        End Get
        Set(ByVal value As String)
            newPropertyValue2 = value
        End Set
    End Property   
End Class

我编写的通过反射查看类的类如下所示：

Public Class ObjectCompare
    Private _OriginalObject As PropertyInfo()

    Public Property OriginalObject() As PropertyInfo()
        Get
            Return _OriginalObject
        End Get
        Set(ByVal value As PropertyInfo())
            _OriginalObject = value
        End Set
    End Property

    Public Sub CompareObjects()
        Dim property_value As Object

        For i As Integer = 0 To OriginalObject.Length - 1
            If OriginalObject(i).GetIndexParameters().Length = 0 Then
                Dim propInfo As PropertyInfo = OriginalObject(i)

                Try
                    property_value = propInfo.GetValue(Me, Nothing)
                Catch ex As TargetException
                End Try   
            End If
        Next
    End Sub
End Class

我在 property_value = propInfo.GetValue(Me, Nothing) 行上放了一个断点，看看结果是什么。

这是我如何调用我的代码：

Dim test As New Class2
test.NewProperty2 = "2"

Dim go As New ObjectCompare
Dim propInf As PropertyInfo()
propInf = test.GetType.GetProperties()

go.OriginalObject = propInf

go.CompareObjects()

通过反射我可以看到PropertyName和Type，我需要的只是Property的值！现在，当我到达断点时，我得到一个 TargetException 并且错误消息显示“对象与目标类型不匹配”。现在是凌晨 1 点，我很伤心，现在有任何帮助将不胜感激。我已经搜索了 MSDN 和 Google 到死，然后最后一次寻找乐趣；）

4

2 回答 2

21

Me指的是ObjectCompare对象，它不同于PropertyInfo派生对象的类 ( Class2)。您还需要传入您从中检索对象的类型的PropertyInfo对象。

Public Sub CompareObjects(ByVal It as Object)
    Dim property_value As Object

    For i As Integer = 0 To OriginalObject.Length - 1
        If OriginalObject(i).GetIndexParameters().Length = 0 Then
            Dim propInfo As PropertyInfo = OriginalObject(i)

            Try
                property_value = propInfo.GetValue(It, Nothing)
            Catch ex As TargetException
            End Try   
        End If
    Next
End Sub

go.CompareObjects(test)
于 2008-11-22T00:41:45.477 回答
1

我不太确定我知道你想在这里做什么，但我会试一试。

这是我提出的代码：

来电：

        Dim test As New Class2
        test.NewProperty2 = "2"


        Dim go As New ObjectCompare
        go.CompareObjects(test)

类：

Public Class Class2
    Private newPropertyValue2 As String

    Public Property NewProperty2() As String
        Get
            Return newPropertyValue2
        End Get
        Set(ByVal value As String)
            newPropertyValue2 = value
        End Set
    End Property
End Class

比较：

 Public Class ObjectCompare

    Public Sub CompareObjects(ByVal MyType As Object)

        For Each Prop In MyType.GetType().GetProperties()
            Dim value = Prop.GetValue(MyType, Nothing)
            Console.WriteLine(value)
        Next
        Console.ReadLine()
    End Sub
End Class
于 2008-11-22T00:49:35.633 回答