求vb编程：加解密问题。

来源：百度知道 编辑：UC知道 时间：2024/06/20 22:28:32
编写一个加解密程序，输入一个字符串，返回值为加密后的字符串。加密方法为0-9，a-z按序号依次向后移动5个位置。如1变成6，5变为a，a变为z,z变为4。解密则反向进行。用函数形式，mid函数

'加密的按钮,text1里是原文, 密文在text2显示
Private Sub Command1_Click()
Dim Rule As String
Dim str1 As String, str2 As String
Dim I As Integer

Rule = "0123456789abcdefghijklmnopqrstuvwxyz01234"
str1 = Text1.Text

For I = 1 To Len(str1)
str2 = str2 & Mid(Rule, InStr(1, Rule, Mid(str1, I, 1)) + 5, 1)
Next

Text2.Text = str2
End Sub

'解密的按钮,text1里是密文, 解密后的原文在text2显示
Private Sub Command2_Click()
Dim Rule As String
Dim str1 As String, str2 As String
Dim I As Integer

Rule = "0123456789abcdefghijklmnopqrstuvwxyz01234"
str1 = Text1.Text

For I = 1 To Len(str1)
str2 = str2 & Mid(Rule, InStrRev(Rule, Mid(str1, I, 1)) - 5, 1)
Next

Text2.Text = str2
End Sub