我有以下代码编译没有问题。当然,在执行 Dim C As IDoThingsC = GetThing_C()
时,我遇到了无效的转换异常。我错过了什么吗?您是否想返回一个不满足函数返回值的接口(interface)要求的对象?
Public Class ClassA
Public Sub DoThings_A()
Debug.Print("Doing A things...")
End Sub
End Class
Public Class ClassB
Implements IDoThingsC
Public Sub DoThings_B()
Debug.Print("Doing B things...")
End Sub
Public Sub DoThings_C() Implements IDoThingsC.DoThings_C
Debug.Print("Doing C things...")
End Sub
End Class
Public Interface IDoThingsC
Sub DoThings_C()
End Interface
Public Class aTest
Public Sub Test()
Dim C As IDoThingsC = GetThing_C()
C.DoThings_C()
End Sub
Public Function GetThing_C() As IDoThingsC
Dim Thing As ClassA = New ClassA
Thing.DoThings_A()
Return Thing
End Function
End Class
最佳答案
使用Option Strict On
位于源代码文件的顶部以捕获此类问题。您将收到编译时错误而不是运行时错误:
error BC30512: Option Strict On disallows implicit conversions from 'ClassA' to 'IDoThingsC'.
关于vb.net - 为什么接口(interface)不是强类型的?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/2030020/