public string funbase64string(string base64)
{
StringBuilder builder = new StringBuilder();
foreach (char c in base64)
{
if (System.Web.HttpUtility.UrlEncode(c.ToString()).Length > 1)
{
builder.Append(System.Web.HttpUtility.UrlEncode(c.ToString(), System.Text.UnicodeEncoding.GetEncoding("GBK")).ToUpper());
}
else
{
builder.Append(c);
}
}
return builder.ToString();
}