webapi下的web请求

先看webapi提供的服务：

        [HttpPost]
         public ResultBaseModel SiteList(SiteModel param)
         {
             ResultBaseModel resultModel = new ResultBaseModel();

             var sites = new List<Site>();

             sites.Add(new Site { SiteId = , Title = "百度", Uri = "www.baidu.com" });
             sites.Add(new Site { SiteId = , Title = "博客园首页", Uri = "www.cnblogs.com" });
             sites.Add(new Site { SiteId = , Title = "博问", Uri = "q.cnblogs.com" });
             sites.Add(new Site { SiteId = , Title = "新闻", Uri = "news.cnblogs.com" });
             sites.Add(new Site { SiteId = , Title = "招聘", Uri = "job.cnblogs.com" });

             try
             {

                 var result = (from Site site in sites
                               where site.SiteId > param.StartId
                               select site)
                                 .Take(param.ItemCount)
                                 .ToList();
                 resultModel.IsSuccess = true;
                 resultModel.Data = sites;

             }
             catch (Exception ex)
             {
                 resultModel.IsSuccess = false;
                 resultModel.Message = ex.Message;
             }

             return resultModel;
         }

客户端调用：

    var requestJson = JsonConvert.SerializeObject(new { StartId = , ItemCount =  });

             var url = "http://localhost:8084/api/CenterShedule/SiteList";
             var responseJson = GetResponseWithNoContentPress(requestJson, url);
             Console.WriteLine(responseJson);

通用的post方法：

         public static string GetResponseWithNoContentPress(string objStr, string url)
         {
             string result = "";
             StreamReader reader = null;
             System.IO.Stream stream = null;
             WebResponse response = null;
             HttpWebRequest request = null;

             try
             {
                 byte[] byteArray = Encoding.UTF8.GetBytes(objStr);
                 request = (HttpWebRequest)WebRequest.Create(url);
                 request.ContentType = "application/json; charset=urf-8";
                 request.Accept = "application/json";
                 request.ContentLength = byteArray.Length;
                 request.KeepAlive = false;
                 request.Method = "POST";
                 request.Timeout = ;
                 System.IO.Stream dataStream = request.GetRequestStream();
                 dataStream.Write(byteArray, , byteArray.Length);
                 dataStream.Close();
                 response = request.GetResponse();
                 stream = response.GetResponseStream();
                 reader = new System.IO.StreamReader(stream, Encoding.UTF8);

                 result = reader.ReadToEnd();
             }
             catch (Exception ex)
             {
                 Console.WriteLine(ex.Message);
             }
             finally
             {
                 if (reader != null)
                 {
                     reader.Close();
                 }
                 if (stream != null)
                 {
                     stream.Close();
                 }
                 if (response != null)
                 {
                     response.Close();
                 }
                 if (request != null)
                 {
                     request.Abort();
                     request = null;
                 }
             }
             return result;
         }

request.Accept = "application/json"; 这一句可以不用指定返回的类型，webapi自动返回json数据，可是我要返回xml数据怎么办？直接改：request.Accept = "application/xml";这时候请求会报错，报出服务器500错误。于是我改接口：

        [HttpPost]
         public string SiteList(SiteModel param)
         {
             return "hello world";
         }

此时返回来的结果如下：

此时，我就想为什么之前的接口，返回不了数据呢？想了下应该是返回的model无法序列化成xml格式，如何让系统帮助生成xml，使用了各种办法，还是返回服务器500错误，最后决定还是自己写个序列化的方法。在此先不提。

post请求还有一种简洁的写法：

           var requestJson = JsonConvert.SerializeObject(new { StartId = , ItemCount =  });

             HttpContent httpContent = new StringContent(requestJson);
             httpContent.Headers.ContentType = new MediaTypeHeaderValue("application/json");

             var httpClient = new HttpClient();

             var responseJson = httpClient.PostAsync("http://localhost:8084/api/CenterShedule/SiteList", httpContent)
                 .Result.Content.ReadAsStringAsync().Result;

顺便把get请求的总结下：

  /// <summary>
         /// get请求，可以对请求头进行多项设置
         /// </summary>
         /// <param name="paramArray"></param>
         /// <param name="url"></param>
         /// <returns></returns>
         public static string GetResponseByGetFull(Dictionary<string, string> paramArray, string url)
         {
             string responseJson = "";

             var httpclient = HTTPHelper.HttpClient;

             url += BuildParam(paramArray);
             var response = httpclient.GetAsync(url).Result;
             if (response.IsSuccessStatusCode)
             {
                 Stream myResponseStream = response.Content.ReadAsStreamAsync().Result;
                 StreamReader myStreamReader = new StreamReader(myResponseStream, Encoding.GetEncoding("utf-8"));
                 responseJson = myStreamReader.ReadToEnd();
                 myStreamReader.Close();
                 myResponseStream.Close();
             }

             return responseJson;
         }

HttpClient：

    public class HTTPHelper
     {
         private static readonly HttpClient HttpClient;
         static HTTPHelper()
         {
             var handler = new HttpClientHandler() { AutomaticDecompression = DecompressionMethods.None };
             HttpClient = new HttpClient(handler);

             HttpClient.DefaultRequestHeaders.Accept.Clear();
             HttpClient.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
         }

BuildParam：

        private static string BuildParam(Dictionary<string, string> paramArray)
         {
             string url = "";
             if (paramArray != null && paramArray.Count > )
             {
                 var parms = "";
                 foreach (var item in paramArray)
                 {
                     parms += string.Format("{0}={1}&", item.Key, item.Value);
                 }
                 if (parms != "")
                 {
                     parms = "?" + parms.TrimEnd('&');
                 }
                 url += parms;

             }
             return url;
         }