'VBA Base64 编码/加密函数：
Function Base64Encode(StrA As String) As String 'Base64 编码
On Error GoTo over '排错
Dim buf() As Byte, length As Long, mods As Long
Dim Str() As Byte
Dim i, kk As Integer
kk = Len(StrA) - 1
ReDim Str(kk)
For i = 0 To kk
Str(i) = Asc(Mid(StrA, i + 1, 1))
Next i
Const B64_CHAR_DICT = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
mods = (UBound(Str) + 1) Mod 3 '除以3的余数
length = UBound(Str) + 1 - mods
ReDim buf(length / 3 * 4 + IIf(mods <> 0, 4, 0) - 1)
For i = 0 To length - 1 Step 3
buf(i / 3 * 4) = (Str(i) And &HFC) / &H4
buf(i / 3 * 4 + 1) = (Str(i) And &H3) * &H10 + (Str(i + 1) And &HF0) / &H10
buf(i / 3 * 4 + 2) = (Str(i + 1) And &HF) * &H4 + (Str(i + 2) And &HC0) / &H40
buf(i / 3 * 4 + 3) = Str(i + 2) And &H3F
Next
If mods = 1 Then
buf(length / 3 * 4) = (Str(length) And &HFC) / &H4
buf(length / 3 * 4 + 1) = (Str(length) And &H3) * &H10
buf(length / 3 * 4 + 2) = 64
buf(length / 3 * 4 + 3) = 64
ElseIf mods = 2 Then
buf(length / 3 * 4) = (Str(length) And &HFC) / &H4
buf(length / 3 * 4 + 1) = (Str(length) And &H3) * &H10 + (Str(length + 1) And &HF0) / &H10
buf(length / 3 * 4 + 2) = (Str(length + 1) And &HF) * &H4
buf(length / 3 * 4 + 3) = 64
End If
For i = 0 To UBound(buf)
Base64Encode = Base64Encode + Mid(B64_CHAR_DICT, buf(i) + 1, 1)
Next
over:
End Function
'VBA Base64 解码/解密函数：
Function Base64Decode(B64 As String) As String 'Base64 解码
On Error GoTo over '排错
Dim OutStr() As Byte, i As Long, j As Long
Const B64_CHAR_DICT = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/="
If InStr(1, B64, "=") <> 0 Then B64 = Left(B64, InStr(1, B64, "=") - 1) '判断Base64真实长度,除去补位
Dim kk, length As Long, mods As Long
mods = Len(B64) Mod 4
length = Len(B64) - mods
ReDim OutStr(length / 4 * 3 - 1 + Switch(mods = 0, 0, mods = 2, 1, mods = 3, 2))
For i = 1 To length Step 4
Dim buf(3) As Byte
For j = 0 To 3
buf(j) = InStr(1, B64_CHAR_DICT, Mid(B64, i + j, 1)) - 1 '根据字符的位置取得索引值
Next
OutStr((i - 1) / 4 * 3) = buf(0) * &H4 + (buf(1) And &H30) / &H10
OutStr((i - 1) / 4 * 3 + 1) = (buf(1) And &HF) * &H10 + (buf(2) And &H3C) / &H4
OutStr((i - 1) / 4 * 3 + 2) = (buf(2) And &H3) * &H40 + buf(3)
Next
If mods = 2 Then
OutStr(length / 4 * 3) = (InStr(1, B64_CHAR_DICT, Mid(B64, length + 1, 1)) - 1) * &H4 + ((InStr(1, B64_CHAR_DICT, Mid(B64, length + 2, 1)) - 1) And &H30) / 16
ElseIf mods = 3 Then
OutStr(length / 4 * 3) = (InStr(1, B64_CHAR_DICT, Mid(B64, length + 1, 1)) - 1) * &H4 + ((InStr(1, B64_CHAR_DICT, Mid(B64, length + 2, 1)) - 1) And &H30) / 16
OutStr(length / 4 * 3 + 1) = ((InStr(1, B64_CHAR_DICT, Mid(B64, length + 2, 1)) - 1) And &HF) * &H10 + ((InStr(1, B64_CHAR_DICT, Mid(B64, length + 3, 1)) - 1) And &H3C) / &H4
End If
For i = 0 To UBound(OutStr)
Base64Decode = Base64Decode & Chr(OutStr(i))
Next i '读取解码结果
over:
End Function
有帮助的多给鲜花，谢谢大家了。