C#网络编程之Http请求
本片篇分享简单介绍C#中的Http请求,前几天帮朋友的项目封装ApiHelper,我粗糙的结果就如下，想想我真的是差的太远了。还有一位架构师也在封装这个Helper , 所以最后的结果当然是使用大牛的封装，这篇分享后，准备学习下他的封装，配置，错误处理机制等思想。不过这次也使我对C#网络编程了解的更多，算是一次学习经历吧。真心喜欢和老司机合作，下一阶段将会持续跟这位朋友学习项目底层的封装，和他谦虚的态度，有这样的机会也是幸运的。
你可以将其封装成自己的HttpHelper，经朋友建议，统一Http请求的入参和出参。在HttpClient方面也参考了dudu的关于httpclient预热的文章。C#中HttpClient使用注意：预热与长连接。
为了做到统一入参和出参，定义了Req<T>泛型类和Resp<T>泛型类。你可以根据自己的需要进行拓展。
1 public class Req<T> 2 { 3 /// <summary> 4 /// 传入数据 5 /// </summary> 6 public T Input { get; set; } 7 /// <summary> 8 /// 请求地址 9 /// </summary> 10 public string Url { get; set; } 11 }
1 public class Resp<T> 2 { 3 /// <summary> 4 /// 错误消息 5 /// </summary> 6 public string ErrorMsg { get; set; } 7 /// <summary> 8 /// 状态码 9 /// </summary> 10 public int StatusCode { get; set; } 11 /// <summary> 12 /// 返回数据 13 /// </summary> 14 public T RespData { get; set; } 15 }
虽然保持了httpClient对象复用，但需要注意的是，在设置了httpClient，并且发生了一次请求之后，不能再对其属性进行重新设置。这也正是我又定义了一个fileClient的理由。
1 #region HttpClient版本 2 private static readonly string _baseAddress = ConfigurationManager.AppSettings["api-server"];//配置BaseUrl eg.http://localhost:1234 3 private static readonly HttpClient _httpClient; 4 private static readonly HttpClient _fileClient; 5 6 static ApiHelper() 7 { 8 #region 初始化和预热 httpClient 9 _httpClient = new HttpClient(); 10 _httpClient.BaseAddress = new Uri(_baseAddress); 11 _httpClient.Timeout = TimeSpan.FromMilliseconds(2000); 12 _httpClient.DefaultRequestHeaders.Add("Accept", "application/json");//application/xml 想Accept的数据格式 13 14 _httpClient.SendAsync(new HttpRequestMessage 15 { 16 Method = new HttpMethod("HEAD"), 17 RequestUri = new Uri(_baseAddress + "/api/test/HttpClientHot") 18 }) 19 .Result.EnsureSuccessStatusCode(); 20 #endregion 21 22 #region 初始化和预热 fileClient 23 24 _fileClient = new HttpClient(); 25 _fileClient.BaseAddress = new Uri(_baseAddress + "/api/test/HttpClientHot"); 26 _fileClient.MaxResponseContentBufferSize = 256000; 27 28 #endregion 29 } 30 31 /// <summary> 32 /// http Get请求 33 /// </summary> 34 /// <typeparam name="T">入参类型</typeparam> 35 /// <typeparam name="TResult">出参类型</typeparam> 36 /// <param name="req">入参对象</param> 37 /// <returns></returns> 38 public static async Task<Resp<TResult>> GetAsync<T, TResult>(Req<T> req) 39 { 40 try 41 { 42 var result =await _httpClient.GetAsync(req.Url).Result.Content.ReadAsStringAsync(); 47 return new Resp<TResult>() { Data = JsonHelper.JsonDeserialize<TResult>(result) }; 48 } 49 catch(Exception ex) 50 { 51 52 } 53 return new Resp<TResult>() { Data = JsonHelper.JsonDeserialize<TResult>("") }; 54 55 } 56 57 /// <summary> 58 /// http Post请求 59 /// </summary> 60 /// <typeparam name="T">入参类型</typeparam> 61 /// <typeparam name="TResult">出参类型</typeparam> 62 /// <param name="req">入参对象</param> 63 /// <returns></returns> 64 public static async Task<Resp<TResult>> PostAsJsonAsync<T, TResult>(Req<T> req) 65 { 66 var result = await _httpClient.PostAsJsonAsync(req.Url, req.Input).Result.Content.ReadAsStringAsync(); 67 return new Resp<TResult>() { Data = JsonHelper.JsonDeserialize<TResult>(result) }; 68 } 69 70 /// <summary> 71 /// 上传文件 72 /// </summary> 73 /// <typeparam name="T"></typeparam> 74 /// <typeparam name="TResult"></typeparam> 75 /// <param name="req"></param> 76 /// <param name="filePath"></param> 77 /// <returns></returns> 78 public static async Task<Resp<TResult>> SendFile<T, TResult>(Req<T> req, string filePath)//D:\\white.jpg 79 { 80 //_fileClient.DefaultRequestHeaders.Add("user-agent", "User-Agent Mozilla/5.0 (Windows NT 10.0; WOW64; Trident/7.0; Touch; MALNJS; rv:11.0) like Gecko");//设置请求头 81 // 读文件流 82 FileStream fs = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.Read); 83 HttpContent fileContent = new StreamContent(fs);//为文件流提供的HTTP容器 84 fileContent.Headers.ContentType = MediaTypeHeaderValue.Parse("multipart/form-data");//设置媒体类型 85 MultipartFormDataContent mulContent = new MultipartFormDataContent("----");//创建用于可传递文件的容器 86 string fileName = filePath.Substring(filePath.LastIndexOf("/") + 1); 87 mulContent.Add(fileContent, "form", fileName);//第二个参数是表单名，第三个是文件名。 88 HttpResponseMessage response = await _fileClient.PostAsync(req.Url, mulContent); 89 response.EnsureSuccessStatusCode(); 90 string result = await response.Content.ReadAsStringAsync(); 91 return new Resp<TResult>() { Data = JsonHelper.JsonDeserialize<TResult>(result) }; 92 } 93 94 /// <summary> 95 /// 下载 96 /// </summary> 97 /// <param name="url"></param> 98 /// <returns></returns> 99 public static async Task<Resp<byte[]>> HttpDownloadData<T>(Req<T> req) 100 { 101 var byteres = await _fileClient.GetByteArrayAsync(req.Url); 102 return new Resp<byte[]>() { Data = byteres }; 103 } 104 105 #endregion 106 }
另外分享下HttpWebRequest来实现的请求。HttpWebRequest需要你自行设置很多内容，当然这也证明其内容丰富。下面代码包含了post,get，以及上传。
/// <summary> /// Post Http请求 /// </summary> /// <param name="url">请求地址</param> /// <param name="postData">传输数据</param> /// <param name="timeout">超时时间</param> /// <param name="contentType">媒体格式</param> /// <param name="encode">编码</param> /// <returns>泛型集合</returns> public static List<T> PostAndRespList<T>(string url, string postData, int timeout = 5000, string contentType = "application/json;", string encode = "UTF-8") { if (!string.IsNullOrEmpty(url) && !string.IsNullOrEmpty(encode) && !string.IsNullOrEmpty(contentType) && postData != null) { // webRequest.Headers.Add("Authorization", "Bearer " + "SportApiAuthData"); HttpWebResponse webResponse = null; Stream responseStream = null; Stream requestStream = null; StreamReader streamReader = null; try { string respstr = GetStreamReader(url, responseStream, requestStream, streamReader, webResponse, timeout, encode, postData, contentType); return JsonHelper.JsonDeserialize<List<T>>(respstr); } catch (Exception ex) { } finally { if (responseStream != null) responseStream.Dispose(); if (webResponse != null) webResponse.Dispose(); if (requestStream != null) requestStream.Dispose(); if (streamReader != null) streamReader.Dispose(); } } return null; } /// <summary> /// Post Http请求 /// </summary> /// <param name="url">请求地址</param> /// <param name="postData">传输数据</param> /// <param name="timeout">超时时间</param> /// <param name="contentType">媒体格式</param> /// <param name="encode">编码</param> /// <returns>泛型集合</returns> public static T PostAndRespSignle<T>(string url, int timeout = 5000, string postData = "", string contentType = "application/json;", string encode = "UTF-8") { if (!string.IsNullOrEmpty(url) && !string.IsNullOrEmpty(encode) && !string.IsNullOrEmpty(contentType) && postData != null) { // webRequest.Headers.Add("Authorization", "Bearer " + "SportApiAuthData"); HttpWebResponse webResponse = null; Stream responseStream = null; Stream requestStream = null; StreamReader streamReader = null; try { string respstr = GetStreamReader(url, responseStream, requestStream, streamReader, webResponse, timeout, encode, postData, contentType); return JsonHelper.JsonDeserialize<T>(respstr); } catch (Exception ex) { } finally { if (responseStream != null) responseStream.Dispose(); if (webResponse != null) webResponse.Dispose(); if (requestStream != null) requestStream.Dispose(); if (streamReader != null) streamReader.Dispose(); } } return default(T); } /// <summary> /// Post Http请求 /// </summary> /// <param name="url"></param> /// <param name="postData"></param> /// <param name="timeout"></param> /// <param name="contentType"></param> /// <param name="encode"></param> /// <returns>响应流字符串</returns> public static string PostAndRespStr(string url, int timeout = 5000, string postData = "", string contentType = "application/json;", string encode = "UTF-8") { if (!string.IsNullOrEmpty(url) && !string.IsNullOrEmpty(encode) && !string.IsNullOrEmpty(contentType) && postData != null) { HttpWebResponse webResponse = null; Stream responseStream = null; Stream requestStream = null; StreamReader streamReader = null; try { return GetStreamReader(url, responseStream, requestStream, streamReader, webResponse, timeout, encode, postData, contentType); } catch (Exception ex) { } finally { if (responseStream != null) responseStream.Dispose(); if (webResponse != null) webResponse.Dispose(); if (requestStream != null) requestStream.Dispose(); if (streamReader != null) streamReader.Dispose(); } } return null; } private static string GetStreamReader(string url, Stream responseStream, Stream requestStream, StreamReader streamReader, WebResponse webResponse, int timeout, string encode, string postData, string contentType) { byte[] data = Encoding.GetEncoding(encode).GetBytes(postData); HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url); SetAuth(webRequest); webRequest.Method = "POST"; webRequest.ContentType = contentType + ";" + encode; webRequest.ContentLength = data.Length; webRequest.Timeout = timeout; requestStream = webRequest.GetRequestStream(); requestStream.Write(data, 0, data.Length); webResponse = (HttpWebResponse)webRequest.GetResponse(); responseStream = webResponse.GetResponseStream(); if (responseStream == null) { return ""; } streamReader = new StreamReader(responseStream, Encoding.GetEncoding(encode)); return streamReader.ReadToEnd(); } /// <summary> /// Post文件流给指定Url /// </summary> /// <param name="url">url</param> /// <param name="filePath">文件路径</param> /// <returns>响应流字符串</returns> public static string PostFile(string url, string filePath, string contentType = "application/octet-stream", string encode = "UTF-8") { if (!string.IsNullOrEmpty(url) && !string.IsNullOrEmpty(encode) && !string.IsNullOrEmpty(contentType) && !string.IsNullOrEmpty(filePath)) { Stream requestStream = null; Stream responseStream = null; StreamReader streamReader = null; FileStream fileStream = null; try { // 设置参数 HttpWebRequest webRequest = WebRequest.Create(url) as HttpWebRequest; SetAuth(webRequest); webRequest.AllowAutoRedirect = true; webRequest.Method = "POST"; string boundary = DateTime.Now.Ticks.ToString("X"); // 随机分隔线 webRequest.ContentType = "multipart/form-data;charset=" + encode + ";boundary=" + boundary; byte[] itemBoundaryBytes = Encoding.UTF8.GetBytes("\r\n--" + boundary + "\r\n");//消息开始 byte[] endBoundaryBytes = Encoding.UTF8.GetBytes("\r\n--" + boundary + "--\r\n");//消息结尾 var fileName = filePath.Substring(filePath.LastIndexOf("/") + 1); //请求头部信息 string postHeader = string.Format("Content-Disposition:form-data;name=\"media\";filename=\"{0}\"\r\nContent-Type:{1}\r\n\r\n", fileName, contentType); byte[] postHeaderBytes = Encoding.UTF8.GetBytes(postHeader); fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read); byte[] fileByteArr = new byte[fileStream.Length]; fileStream.Read(fileByteArr, 0, fileByteArr.Length); fileStream.Close(); requestStream = webRequest.GetRequestStream(); requestStream.Write(itemBoundaryBytes, 0, itemBoundaryBytes.Length); requestStream.Write(postHeaderBytes, 0, postHeaderBytes.Length); requestStream.Write(fileByteArr, 0, fileByteArr.Length); requestStream.Write(endBoundaryBytes, 0, endBoundaryBytes.Length); requestStream.Close(); responseStream = webRequest.GetResponse().GetResponseStream();//发送请求，得到响应流 if (responseStream == null) return string.Empty; streamReader = new StreamReader(responseStream, Encoding.UTF8); return streamReader.ReadToEnd(); } catch (Exception ex) { } finally { } } return null; } /// <summary> /// Get http请求 /// </summary> /// <param name="url">请求地址</param> /// <param name="timeout">超时时间</param> /// <param name="encode">编码</param> /// <returns>返回单个实体</returns> public static T GetSingle<T>(string url, int timeout = 5000, string encode = "UTF-8") { //HttpWebRequest对象 //HttpClient->dudu 调用预热处理 //Stream—>Model if (!string.IsNullOrEmpty(url) && !string.IsNullOrEmpty(encode)) { Stream responseStream = null; StreamReader streamReader = null; WebResponse webResponse = null; try { string respStr = GetRespStr(url, responseStream, streamReader, webResponse, timeout, encode); return JsonHelper.JsonDeserialize<T>(respStr); } catch (Exception ex) { } finally { if (responseStream != null) responseStream.Dispose(); if (streamReader != null) streamReader.Dispose(); if (webResponse != null) webResponse.Dispose(); } } return default(T); } /// <summary> /// Get http请求 /// </summary> /// <param name="url"></param> /// <param name="timeout"></param> /// <param name="encode"></param> /// <returns>响应流字符串</returns> public static string GetResponseString(string url, int timeout = 5000, string encode = "UTF-8") { if (!string.IsNullOrEmpty(url) && !string.IsNullOrEmpty(encode)) { Stream responseStream = null; StreamReader streamReader = null; WebResponse webResponse = null; try { return GetRespStr(url, responseStream, streamReader, webResponse, timeout, encode); } catch (Exception ex) { } finally { if (responseStream != null) responseStream.Dispose(); if (streamReader != null) streamReader.Dispose(); if (webResponse != null) webResponse.Dispose(); } } return null; } private static string GetRespStr(string url, Stream responseStream, StreamReader streamReader, WebResponse webResponse, int timeout, string encode) { HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(url); webRequest.Method = "GET"; webRequest.Timeout = timeout; webResponse = webRequest.GetResponse(); responseStream = webResponse.GetResponseStream(); if (responseStream == null) { return ""; } streamReader = new StreamReader(responseStream, Encoding.GetEncoding(encode)); return streamReader.ReadToEnd(); }
