Dim s As String ="手机" Dim s1 As new List (of String) s1.add("电视机") s1.add("收音机") s1.add("笔记本电脑") For i As Integer = 0 To s1.Count-1 If s1(i) = s MessageBox.show(s & "已包含在本集合中!") Exit For ElseIf i = s1.Count-1 MessageBox.show( s & "未包含在本集合中!") End If Next