有的时候我们使用RC4来编码数据，但产生的字符串已经不是正常的字符串，在存储过程中会造成混乱，以致于无法用RC4来还原原来的数据。解决问题办法就是将这个不正常的字符串进行转换后存储，取出时再转换回来。
两个函数如下：
' 将一个字符数组转换成以逗号分隔的数字字符串 ' 作者：朱亦文 Function String2Num(ByVal s As String) As String If s = "" Then Exit Function Dim i As Integer, l As Integer Dim ByteGB() As Byte ByteGB = s l = UBound(ByteGB) For i = 0 To l String2Num = String2Num & "," & ByteGB(i) Next String2Num = Mid(String2Num, 2) End Function ' 将以逗号分隔的数字字符串还原成一个字符数组 ' 作者：朱亦文 Function Num2String(ByVal s As String) As String If s = "" Then Exit Function Dim aCh, i As Integer, l As Integer aCh = Split(s, ",") l = UBound(aCh) ReDim ByteGB(l) As Byte For i = 0 To l ByteGB(i) = CInt(aCh(i)) Next Num2String = ByteGB End Function
附: 刘小军先生的RC4函数
' conKey是加密时的密钥，可以自己更改
Private Const conKey = "zy123456789"
Public Function RC4(strInp As String) As String
' ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
' RC4加密函数
' ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
' 适用于使用UNICODE的双字节ACCESS，测试证明支持中英文混合的文本加密
' ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
' 参数：
' strInp 需要加密或解密的字符串
' ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
'
' 这是修改过的RC4加密方法，主要更改是把密钥固定在程序中了
' 使用方法：
' RC4("345G4")得到"345G4"加密之后的字符串
' RC4(RC4("345G4"))可以将加密后的字符串还原为"345G4"
'
Dim s(0 To 255) As Byte, K(0 To 255) As Byte, i As Long
Dim j As Long, Temp As Byte, Y As Byte, t As Long, x As Long
Dim Outp As String
For i = 0 To 255
s(i) = i
Next
j = 1
For i = 0 To 255
If j > Len(conKey) Then j = 1
K(i) = Asc(Mid(conKey, j, 1))
j = j + 1
Next i
j = 0
For i = 0 To 255
j = (j + s(i) + K(i)) Mod 256
Temp = s(i)
s(i) = s(j)
s(j) = Temp
Next i
i = 0
j = 0
For x = 1 To Len(strInp)
i = (i + 1) Mod 256
j = (j + s(i)) Mod 256
Temp = s(i)
s(i) = s(j)
s(j) = Temp
t = (s(i) + (s(j) Mod 256)) Mod 256
Y = s(t)
Outp = Outp & ChrW(AscW(Mid(strInp, x, 1)) Xor Y)
Next
RC4 = Outp
End Function