Option Explicit Private Const cstBase64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/" Private arrBase64() As String Public Function Base64Encode(strSource As String) As String On Error Resume Next If UBound(arrBase64) = -1 Then arrBase64 = Split(StrConv(cstBase64,vbUnicode),vbNullChar) End If Dim arrB() As Byte,bTmp(2) As Byte,bT As Byte Dim I As Long,J As Long arrB = StrConv(strSource,vbFromUnicode) J = UBound(arrB) For I = 0 To J Step 3 Erase bTmp bTmp(0) = arrB(I + 0) bTmp(1) = arrB(I + 1) bTmp(2) = arrB(I + 2) bT = (bTmp(0) And 252) / 4 Base64Encode = Base64Encode & arrBase64(bT) bT = (bTmp(0) And 3) * 16 bT = bT + bTmp(1) / 16 Base64Encode = Base64Encode & arrBase64(bT) bT = (bTmp(1) And 15) * 4 bT = bT + bTmp(2) / 64 If I + 1 <= J Then Base64Encode = Base64Encode & arrBase64(bT) Else Base64Encode = Base64Encode & "=" End If bT = bTmp(2) And 63 If I + 2 <= J Then Base64Encode = Base64Encode & arrBase64(bT) Else Base64Encode = Base64Encode & "=" End If Next End Function Public Function Base64Decode(strEncoded As String) As String On Error Resume Next Dim arrB() As Byte,bTmp(3) As Byte,bT As Long,bRet() As Byte Dim I As Long,J As Long arrB = StrConv(strEncoded,vbFromUnicode) J = InStr(strEncoded & "=","=") - 2 ReDim bRet(J - J / 4 - 1) For I = 0 To J Step 4 Erase bTmp bTmp(0) = (InStr(cstBase64,Chr(arrB(I))) - 1) And 63 bTmp(1) = (InStr(cstBase64,Chr(arrB(I + 1))) - 1) And 63 bTmp(2) = (InStr(cstBase64,Chr(arrB(I + 2))) - 1) And 63 bTmp(3) = (InStr(cstBase64,Chr(arrB(I + 3))) - 1) And 63 bT = bTmp(0) * 2 ^ 18 + bTmp(1) * 2 ^ 12 + bTmp(2) * 2 ^ 6 + bTmp(3) bRet((I / 4) * 3) = bT / 65536 bRet((I / 4) * 3 + 1) = (bT And 65280) / 256 bRet((I / 4) * 3 + 2) = bT And 255 Next Base64Decode = StrConv(bRet,vbUnicode) End Function Private Sub Command1_Click() Msg<a href="https://www.jb51.cc/tag/Box/" target="_blank" class="keywords">Box</a> Base64Encode("这是<a href="https://www.jb51.cc/tag/zhongwen/" target="_blank" class="keywords">中文</a>") Msg<a href="https://www.jb51.cc/tag/Box/" target="_blank" class="keywords">Box</a> Base64Decode("1eLKx9bQzsQ=") 'Msg<a href="https://www.jb51.cc/tag/Box/" target="_blank" class="keywords">Box</a> Base64Decode("asdfasdfasdfasd") '没有容错处理。。 End Sub