Base64加密解密的方法

    Public Function Encode(ByVal str As String) As String

        Dim encbuff As Byte() = System.Text.Encoding.UTF8.GetBytes(str)

        Return Convert.ToBase64String(encbuff)

    End Function

    Public Function Decode(ByVal str As String) As String

        Dim decbuff As Byte() = Convert.FromBase64String(str)

        Return System.Text.Encoding.UTF8.GetString(decbuff)

    End Function

转自  http://www.cnblogs.com/modu-xl/articles/2169967.html