Base64

2022-07-15 80酷酷网 80kuku.com

　　快过生蛋节了，俺送大家一段Base64的程序，入口函数是Encode(bytFile() as Byte)，bytFile是一个Byte型的数组，返回一个字符串。对了，传入的数组不大于32767个元素（这一点没做什么较验，多了会出错哦！嘻嘻）
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Private m_bytIndex(0 To 63) As Byte

'****************************************************
'*                                                  *
'*-- To encode file data with Base64 method.        *
'*                                                  *
'****************************************************
Public Function Encode(bytFile() As Byte) As String

    Dim i As Long, j As Long
    Dim strRslt As String

    i = 0

    For i = 0 To UBound(bytFile) - ((UBound(bytFile) + 1) Mod 3) Step 3
        strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(i) And 252) / 4)))
        strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(i) And 3) * 16 + (bytFile(i + 1) And 240) / 16)))
        strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(i + 1) And 15) * 4 + (bytFile(i + 2) And 192) / 64)))
        strRslt = strRslt + Chr(m_bytIndex(Int(bytFile(i + 2) And 63)))
    Next i

    Select Case ((UBound(bytFile) + 1) Mod 3)
        Case 1
            strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(UBound(bytFile)) And 252) / 4)))
            strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(UBound(bytFile)) And 3) * 16)))
            strRslt = strRslt + "=="
        Case 2
            strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(UBound(bytFile) - 1) And 252) / 4)))
            strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(UBound(bytFile) - 1) And 3) * 16 + (bytFile(UBound(bytFile)) And 240) / 16)))
            strRslt = strRslt + Chr(m_bytIndex(Int((bytFile(UBound(bytFile)) And 15) * 4)))
            strRslt = strRslt + "="
    End Select
    Encode = strRslt

End Function

'****************************************************
'*                                                  *
'*-- Class Initialize to initialize the array of    *
'*   base64 coding.                                 *
'*                                                  *
'****************************************************
Private Sub Class_Initialize()

    m_bytIndex(0) = 65 'Asc("A")
    m_bytIndex(1) = 66 'Asc("B")
    m_bytIndex(2) = 67 'Asc("C")
    m_bytIndex(3) = 68 'Asc("D")
  &n