iOS Question Transparent for navigation bar

Sub SetNavigationBarTransparent
    Dim NaObj As NativeObject = NavControl
    NaObj.GetField("view").RunMethod("setBackgroundColor:",Array(NaObj.ColorToUIColor(Colors.Transparent)))
  
    NaObj = NaObj.GetField("navigationBar")
    NaObj.RunMethod("setTranslucent:",Array(True))
  
    Dim NaObj2 As NativeObject
    NaObj2 = NaObj2.Initialize("UIImage").RunMethod("new",Array())
  
    NaObj.RunMethod("setBackgroundImage:forBarMetrics:",Array(NaObj2,0))
    NaObj.RunMethod("setShadowImage:",Array(NaObj2))
    NaObj.RunMethod("setBackgroundColor:",Array(NaObj.ColorToUIColor(Colors.Transparent)))
End Sub

Sub SetNavigationBarAlpha(Alpha As Float,Color As Int)
    Dim NaObj As NativeObject = NavControl
    NaObj = NaObj.GetField("navigationBar")
 
    NaObj.RunMethod("setBarTintColor:",Array(NaObj.ColorToUIColor(Color)))
    NaObj.RunMethod("setTranslucent:",Array(True))
    NaObj.RunMethod("setAlpha:",Array(Alpha))
End Sub