VB.net 函数中是否有任何 IN 运算符，如 SQL 中的运算符
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Is there any IN Operator in VB.net functions like the one in SQL
提问by Alaa
Is there any function or operator like:
是否有任何函数或运算符，例如：
If RoleName in ( "Val1", "Val2" ,"Val2" ) Then
'Go
End If
Instead of:
代替：
If RoleName = "Val1" Or RoleName = "Val2" Or RoleName = "Val2" Then
'Go
End If
回答by LarsTech
Try using an array and then you can use the Contains extension:
尝试使用数组，然后您可以使用包含扩展名：
Dim s() As String = {"Val1", "Val2", "Val3"}
If s.Contains(RoleName) Then
'Go
End If
Or without the declaration line:
或者没有声明行：
If New String() {"Val1", "Val2", "Val3"}.Contains(RoleName) Then
'Go
End If
From the OP, if the Contains extension is not available, you can try this:
从 OP 中，如果包含扩展名不可用，您可以尝试以下操作：
If Array.IndexOf(New String() {"Val1", "Val2", "Val3"}, RoleName) > -1 Then
'Go
End If
回答by Meta-Knight
You can use Contains as shown by LarsTech, but it's also very easy to add an Inextension method:
您可以使用 LarsTech 所示的 Contains ，但添加In扩展方法也很容易：
Public Module Extensions
<Extension()> _
Public Function [In](Of T)(value As T, ParamArray collectionValues As T()) As Boolean
Return collectionValues.Contains(value)
End Function
End Module
You can use it like this:
你可以这样使用它：
If RoleName.In("Val1", "Val2", "Val3") Then
'Go
End If
回答by Botz3000
You could also use a Select..Casestatement:
您还可以使用以下Select..Case语句：
Select Case RoleName
Case "Val1", "Val2", "Val3"
' Whatever
End Select
