～ 本人学生 急求～ ！ VB实现字符位移

求助～～ 本人学生 急求～～ ！！ VB实现字符位移
字符位移就是随机产生十个大写字母，子过程movestr（a（）,m,tag as boolean)是把字符数组移动m个位置，当tag为true向左移动，则前m个字符移动到字符数组尾，如abcdefghij左移三个位置后，结果为defghijabc;当tag为false时右移，则后m个字符一道字符数组前，如abcdefghij又移3个字符后，hijabcdefg.其中m是1~10的随机数。如果有高手请尽快给出答案。非常急急~~~万分感谢！！！

[解决办法]
用字符串较简单，给你个思路，将字符串成倍，再取。

VB code

    Dim s As String, tag As Boolean, m As Integer        '产生10个随机大写字母    Dim i As Integer    For i = 1 To 10        Randomize        s = s & Chr(Int(26 * Rnd + 1) + 64)    Next i        Randomize    m = Int(10 * Rnd + 1)   '移位数        Debug.Print s, m    s = s & s   '字符串长度成2倍    tag = False    Debug.Print s, Mid(s, IIf(tag, m + 1, 11 - m), 10)  '取移位后的字符串
[解决办法]
VB code
function leftshift(s as string) as string    leftshift = right(s, len(s) - 1) & left(s, 1)end functionfunction rightshift(s as string) as string    leftshift = right(s, 1) & left(s, len(s) - 1)end functionfunction leftshiftn(s as string, n as integer) as string    leftshiftn = s    for i = 1 to n        leftshiftn = leftshift(leftshiftn)    nextend functionfunction rightshiftn(s as string, n as integer) as string    rightshiftn = s    for i = 1 to n        rightshiftn = rightshift(rightshiftn)    nextend function