访问VB.Net结构元素

Question

好吧，某些遗传代码：我有权限的整个负载的结构：

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

而且我希望有一个功能CANDO，我像这样创建：

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 

我打电话CANDO与预填充结构和“writeSupervisor”参数

在调试，b显示为{布尔writeSupervisor}，但是当我试图返回b为布尔，我得到错误：值典型值e'System.Reflection.FieldInfo'不能转换为'布尔'。

任何想法如何可以通过元素名称和测试/比较/返回值“索引”到结构？

Answer 1

您需要调用FieldInfo对象的GetValue方法来获取字段值。

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 

我也推荐你阅读这个：Visual Basic Naming Conventions。