public static string UrlEncode(string str)
{
StringBuilder sb = new StringBuilder();
byte[] byStr = System.Text.Encoding.UTF8.GetBytes(str); //默认是System.Text.Encoding.Default.GetBytes(str)
for (int i = 0; i < byStr.Length; i++)
{
sb.Append(@"%" + Convert.ToString(byStr[i], 16));
}
return (sb.ToString());
}