解决httplistener querystring 中文乱码方案：

在请求到达时候，获取Request.Url,返回get请求参数 键值对

    public class RequestHelper
    {
        public static Dictionary<string, string> EncodeQueryString(Uri uri)
        {
            var ret = new Dictionary<string, string>();
            var q = uri.Query;
            if (q.Length > 0)
            {
                foreach (var p in q.Substring(1).Split(‘&‘))
                {
                    var s = p.Split(new char[] { ‘=‘ }, 2);
                    ret.Add(HttpUtility.UrlDecode(s[0]), HttpUtility.UrlDecode(s[1]));
                }
            }
            return ret;
        }
    }

解决返回json中文格式乱码：

对中午json字符串进行编码 HttpUtility.UrlDecode(“中文”);

  public class ResponseHelper
    {
        public static void Respose(HttpListenerResponse response, string jsonStr = "")
        {
            byte[] buffer = Encoding.UTF8.GetBytes(jsonStr);
            response.ContentLength64 = buffer.Length;
            response.ContentType = "application/json";
            response.ContentEncoding = Encoding.UTF8;
            response.StatusCode = 200;
            Stream output = response.OutputStream;
            output.Write(buffer, 0, buffer.Length);
            //关闭输出流，释放相应资源
            output.Close();
            response.Close();
        }
    }

转载于：链接

C# 解决httplistener querystring 中文乱码、返回json中文格式乱码