1、算法说明
1)        加密解密
最简单的加密方法是：将每个字母加一序数，例如5，这时：
“A”→”F”,”a” →”f”,”B” →”G”,”b” →”g”……”Y” →”D”, ”y” →”d”,”Z” →”E”, ”z” →”e”
解密是加密的逆操作。
界面如下：


代码如下：
                  Option Explicit
                  Private Sub Command1_Click()
                        Dim strInput$, Code$, Record$, c As String * 1
                        Dim i%, length%, iAsc%
                        strInput = Text1.Text
                        length = Len(Trim(strInput))
                        Code = ""
                        For i = 1 To length
                              c = mid(strInput, i, 1)
                              Select Case c
                                   Case "A" To "Z"
                                         iAsc = Asc(c) + 5
                                         If iAsc > Asc("Z") Then iAsc = iAsc - 26
                                         Code = Code & Chr(iAsc)
                                   Case "a" To "z"
                                         iAsc = Asc(c) + 5
                                         If iAsc > Asc("z") Then iAsc = iAsc - 26
                                         Code = Code & Chr(iAsc)
                                   Case Else
                                         Code = Code & c
                              End Select
                        Next i
                        Text2.Text = Code
                  End Sub
                  Private Sub Command3_Click()
                  Text1.Text = ""
                  Text2.Text = ""
                  Text3.Text = ""
                  Text1.SetFocus
                  End Sub 首页 1 2 3 尾页