扩展方法的一个很好的用途是使语言更具功能性
Sub Main()
Dim strings = { "One", "Two", "Three" }
strings.Join(Environment.NewLine).Print()
End Sub
<Extension>
Public Function Join(strings As IEnumerable(Of String), separator As String) As String
Return String.Join(separator, strings)
End Function
<Extension>
Public Sub Print(text As String)
Console.WriteLine(text)
End Sub