asp.net – 最有效的方式…独特的随机字符串

有没有更有效的方法来完成这个过程？

请注意,我不想使用GUID或超过5个字符的任何其他内容….我必须坚持5个字符.

PS：我认为它没有区别,但我的字符串都是区分大小写的.

这是“随机字符串”部分

Public Function GetRandomNumbers(ByVal numChars As Integer) As String
    Dim chars As String() = { _
     "A","B","C","D","E","F",_
     "G","H","I","J","K","L",_
     "M","N","O","P","Q","R",_
     "S","T","U","V","W","X",_
     "Y","Z","0","1","2","3",_
     "4","5","6","7","8","9",_
     "a","b","c","d","e","f",_
     "g","h","i","j","k","l",_
     "m","n","o","p","q","r",_
     "s","t","u","v","w","x",_
     "y","z"}
    Dim rnd As New Random()
    Dim random As String = String.Empty
    Dim i As Integer = 0
    While i < numChars
        random += chars(rnd.[Next](0,62))
        System.Math.Max(System.Threading.Interlocked.Increment(i),i - 1)
    End While
    Return random
End Function