/// <summary>
/// 多部分表单数据(multi-part form-data)的分界(boundary)标识
/// </summary>
/// <returns>分界(boundary)标识字符串</returns>
public static string CreateFormDataBoundary()
{
string now = DateTime.UtcNow.Ticks.ToString();
return(string.Format("-------{0}Boundary{1}", "ALIAS", HashUtil.CalcMD5X(now)));
}