/// <summary>
 /// 对象转字符
 /// </summary>
 /// <param name="value">对象实例</param>
 /// <returns></returns>
 private static string StringifyValue(object value)
 {
     if (value is string)
     {
         return(FormUrlEncodedContentEx.Encode((string)value));
     }
     else if (value is IEnumerable <string> )//集合对象类型。
     {
         StringBuilder sb           = new StringBuilder();
         bool          firstElement = true;
         sb.Append("[");
         foreach (string item in (IEnumerable <string>)value)
         {
             if (firstElement)
             {
                 firstElement = false;
             }
             else
             {
                 sb.Append(",");
             }
             sb.Append("\"");
             sb.Append(FormUrlEncodedContentEx.Encode(item));
             sb.Append("\"");
         }
         sb.Append("]");
         return(sb.ToString());
     }
     else
     {
         throw new InvalidOperationException("FormUrlEncodedContentEx cannot handle " + value.GetType().ToString() + " values");
     }
 }
        /// <summary>
        /// 转换key/value数组为byte数组。
        /// </summary>
        /// <param name="nameValueCollection">key/value数组</param>
        /// <returns></returns>
        private static byte[] GetContentByteArray(IEnumerable <KeyValuePair <string, object> > nameValueCollection)
        {
            if (nameValueCollection == null)
            {
                throw new ArgumentNullException("nameValueCollection");
            }
            StringBuilder stringBuilder = new StringBuilder();

            foreach (KeyValuePair <string, object> current in nameValueCollection)
            {
                if (stringBuilder.Length > 0)
                {
                    stringBuilder.Append('&');
                }
                stringBuilder.Append(FormUrlEncodedContentEx.Encode(current.Key));
                stringBuilder.Append('=');
                if (current.Value is string)
                {
                    stringBuilder.Append(StringifyValue(current.Value));
                }
                else
                {
                    stringBuilder.Append(CoreUtil.GetObjTranNull <string>(current.Value).ToLower());
                }
            }
            return(Encoding.UTF8.GetBytes(stringBuilder.ToString()));
        }