Question

VB.NET自定义函数

自定义了一个FUNCTION函数,在最后END FUNCTION上老是显示出错:"并非在所有代码路径上都返回值".这是什么回事?
代码如下:
Public Function Zuhe(ByVal qa As String) As String
Select Case qa
Case "0"
Return "1"
Case "1"
Return "3"
Case "2"
Return "4"
Case "3"
Return "6"
Case "4"
Return "2"
Case "5"
Return "8"
Case "6"
Return "9"
Case "7"
Return "7"
Case "8"
Return "5"
Case "9"
Return "0"
End Select
End Function

Answer 1

很简单，在end select前再多加一种情况case else return "XXXx",因为你只提供了0-9这10种情况
Public Function Zuhe(ByVal qa As String) As String
Select Case qa
Case "0"
Return "1"
Case "1"
Return "3"
Case "2"
Return "4"
Case "3"
Return "6"
Case "4"
Return "2"
Case "5"
Return "8"
Case "6"
Return "9"
Case "7"
Return "7"
Case "8"
Return "5"
Case "9"
Return "0"
Case else
Return "XXXX"
End Select
End Function