訪問VB.Net結構元素

Question

好吧，某些遺傳代碼：我有權限的整個負載的結構：

public structure Perms 
    dim writeStaff as Boolean 
    dim readStaff as Boolean 
    dim writeSupervisor as Boolean 
    dim readSuperVisor as Boolean 
    ' ... and many more 
End Structure 

而且我希望有一個功能CANDO，我像這樣創建：

public function canDo(p as Perms, whichOne as String) as boolean 
    Dim b as System.Reflection.FieldInfo 
    b = p.GetType().GetField(whichOne) 
    return b 
end function 

我打電話CANDO與預填充結構和「writeSupervisor」參數

在調試，b顯示爲{布爾writeSupervisor}，但是當我試圖返回b爲布爾，我得到錯誤：值典型值e'System.Reflection.FieldInfo'不能轉換爲'布爾'。

任何想法如何可以通過元素名稱和測試/比較/返回值「索引」到結構？

Answer 1

您需要調用FieldInfo對象的GetValue方法來獲取字段值。

Public Function canDo(p As Perms, whichOne As String) As Boolean 
    If (Not String.IsNullOrEmpty(whichOne)) Then 
     Dim info As FieldInfo = p.GetType().GetField(whichOne) 
     If (Not info Is Nothing) Then 
      Dim value As Object = info.GetValue(p) 
      If (TypeOf value Is Boolean) Then 
       Return DirectCast(value, Boolean) 
      End If 
     End If 
    End If 
    Return False 
End Function 

我也推薦你閱讀這個：Visual Basic Naming Conventions。