shift.frm

捕获键盘操作的记录

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "转换成BASE64编码"
   ClientHeight    =   2940
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   3960
   LinkTopic       =   "Form1"
   ScaleHeight     =   2940
   ScaleWidth      =   3960
   StartUpPosition =   3  '窗口缺省
   Begin VB.TextBox Text2 
      Height          =   270
      Left            =   480
      Locked          =   -1  'True
      TabIndex        =   2
      Top             =   1920
      Width           =   2775
   End
   Begin VB.CommandButton Command1 
      Caption         =   "转换成BASE64编码"
      Height          =   615
      Left            =   480
      TabIndex        =   1
      Top             =   960
      Width           =   2775
   End
   Begin VB.TextBox Text1 
      Height          =   270
      Left            =   480
      TabIndex        =   0
      Top             =   360
      Width           =   2775
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Option Explicit
Private Base64TalbeStr(0 To 63) As String * 1
Const Chars64Table As String = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

Public Function StringToBase64(ByRef Text As String) As String  '将字符串转换成Base64码的函数
    Dim CharsInAsc() As Integer, StrInLen As Long '
    Dim i As Long, j As Long
    Dim Base64Len As Long, strout As String
    
    For i = 0 To 63: Base64TalbeStr(i) = Mid$(Chars64Table, i + 1, 1): Next '建立Base64码表数组
    StrInLen = Len(Text)
    If StrInLen = 0 Then Exit Function '输入字符串校验,长度不能为0
    Base64Len = ((StrInLen + 2) \ 3) * 4 '输入字符串的转换为Base64码后的长度
    
    ReDim CharsInAsc(1 To StrInLen)
    For i = 1 To StrInLen: CharsInAsc(i) = Asc(Mid$(Text, i, 1)): Next
    
    ReDim Chars64(0 To Base64Len - 1)
    For i = 1 To StrInLen - 2 Step 3 '一次转换三个字符
        strout = strout & Base64TalbeStr(CharsInAsc(i) \ &H4) '除4，取其高6位
        strout = strout & Base64TalbeStr((CharsInAsc(i) And &H3) * &H10 + _
            CharsInAsc(i + 1) \ &H10) '取第一字节的低二位并　*16，取第二字节的高4位，相加
        strout = strout & Base64TalbeStr((CharsInAsc(i + 1) And &HF) * &H4 + CharsInAsc(i + 2) \ &H40)
             '取第二字节的低4位并　*16，取第三字节的高2位，相加
        strout = strout & Base64TalbeStr(CharsInAsc(i + 2) And &H3F) '取第三字节的低6位
        j = j + 4
    Next i
    Select Case StrInLen - i '当输入的字符不是3的倍数时，继续转换未转换完的输入字符Base64码
        Case 0 '输入为3*n+1 个字符
            strout = strout & Base64TalbeStr(CharsInAsc(i) \ &H4)
            strout = strout & Base64TalbeStr((CharsInAsc(i) And &H3) * &H10)
            strout = strout & "=="
        Case 1 '输入为3*n+2 个字符
            strout = strout & Base64TalbeStr(CharsInAsc(i) \ &H4)
            strout = strout & Base64TalbeStr((CharsInAsc(i) And &H3) * &H10 + CharsInAsc(i + 1) \ &H10)
            strout = strout & Base64TalbeStr((CharsInAsc(i + 1) And &HF) * &H4)
            strout = strout & "="
    End Select
    StringToBase64 = strout
End Function


Private Sub Command1_Click()
    Text2.Text = StringToBase64(Text1.Text)
End Sub