使用反射獲取屬性

Question

我正在嘗試通過執行以下操作來獲取本地路徑的值：

  Dim bar As WebProxy = WebProxy.GetDefaultProxy
  Dim scriptEngine = bar.GetType().GetProperty("ScriptEngine", Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance)
  Dim acs As PropertyInfo = scriptEngine.PropertyType().GetProperty("AutomaticConfigurationScript", Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance)
  Dim localPath As PropertyInfo = acs.PropertyType().GetProperty("LocalPath", Reflection.BindingFlags.Public Or Reflection.BindingFlags.Instance)
  Dim value As String = localPath.GetValue(acs, Nothing).ToString

我很確定這里的問題是我將PropertyInfo對象傳遞給localPath.GetValue，而不是實際的對象本身。 唯一的問題是我無法轉換結果

Dim acs As PropertyInfo = scriptEngine.PropertyType().GetProperty("AutomaticConfigurationScript", Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance)

進入System.Uri AutomaticConfigurationScript並將其傳入，因此出現錯誤“對象與目標類型不匹配”。

有任何想法嗎？

PS我意識到這不是ac＃問題，但不想限制我已將其標記為可能的答案，因為它是一個.Net問題，如果我收到C＃的答案，我就可以翻譯。

Answer 1

您需要在每個步驟中獲取實際的對象，並使用它來獲取下一個屬性：

Dim bar As WebProxy = WebProxy.GetDefaultProxy

Dim scriptEngineProperty = bar.GetType().GetProperty("ScriptEngine", Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance)
Dim scriptEngineObject as Object = scriptEngineProperty.GetValue(bar, Nothing)

Dim acsProperty As PropertyInfo = scriptEngineObject.GetType().GetProperty("AutomaticConfigurationScript", Reflection.BindingFlags.NonPublic Or Reflection.BindingFlags.Instance)
Dim acsObject as Object = acsProperty.GetValue(scriptEngineObject, Nothing)

Dim localPathProperty As PropertyInfo = acsObject.GetType().GetProperty("LocalPath", Reflection.BindingFlags.Public Or Reflection.BindingFlags.Instance)
Dim value As String = localPath.GetValue(acsObject, Nothing).ToString