反射应用之一：根据控件名、属性名进行取值和赋值

'必须引用命名空间System.Reflection,System.ComponentModel
'以下根据控件名和属性名取值
Public Function GetValueControlProperty(ByVal ClassInstance As Object, ByVal ControlName As String, ByVal PropertyName As String) As Object
Dim Result As Object
Dim myType As Type = ClassInstance.GetType
Dim myFieldInfo As FieldInfo = myType.GetField("_" & ControlName, BindingFlags.NonPublic Or _
BindingFlags.Instance Or BindingFlags.Public Or BindingFlags.Instance)
If Not myFieldInfo Is Nothing Then
Dim properties As PropertyDescriptorCollection = TypeDescriptor.GetProperties(myType)
Dim myProperty As PropertyDescriptor = properties.Find(PropertyName, False)
If Not myProperty Is Nothing Then
Dim ctr As Object
ctr = myFieldInfo.GetValue(ClassInstance)
Try
Result = myProperty.GetValue(ctr)
Catch ex As Exception
MsgBox(ex.Message)
End Try
End If
End If
Return Result
End Function
'以下根据控件名和属性名赋值
Public Function SetValueControlProperty(ByVal ClassInstance As Object, ByVal ControlName As String, ByVal PropertyName As String, ByVal Value As Object) As Object
Dim Result As Object
Dim myType As Type = ClassInstance.GetType
Dim myFieldInfo As FieldInfo = myType.GetField("_" & ControlName, BindingFlags.NonPublic _
Or BindingFlags.Instance Or BindingFlags.Public Or BindingFlags.Instance) '加"_"这个是特要紧的
If Not myFieldInfo Is Nothing Then
Dim properties As PropertyDescriptorCollection = TypeDescriptor.GetProperties(myType)
Dim myProperty As PropertyDescriptor = properties.Find(PropertyName, False) '这里设为True就不用区分大小写了
If Not myProperty Is Nothing Then
Dim ctr As Object
ctr = myFieldInfo.GetValue(ClassInstance) '取得控件实例
Try
myProperty.SetValue(ctr, Value)
Result = ctr
Catch ex As Exception
MsgBox(ex.Message)
End Try
End If
End If
Return Result
End Function
'调用
'以下实现Label1.Text=TextBox1.Text,Label2.Text=TextBox2
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim i As Integer
For i = 1 To 2
Me.SetValueControlProperty(Me, "Label" & i.ToString, "Text", GetValueControlProperty(Me, "TextBox" & i.ToString, "Text"))
Next i
End Sub