C# 通过 HttpWebRequest发送数据以及服务器通过Request请求获取数据

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筋斗云
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C# 通过 HttpWebRequest发送数据以及服务器通过Request请求获取数据, 后台请求的三种类型"application/x-www-form-urlencoded"和"multipart/form-data"以及"application/json",对应的服务器端应该获取数据参数的方法

C#中HttpWebRequest的用法详解 可参考:

C#中HttpWebRequest的用法详解
C# HttpWebRequest详解
C# 服务器通过Request获取参数 可参考:
C# WebService 接口 通过Request请求获取json参数

一、客户端和服务器传输数据的类

1、后台程序发送HTTP请求的Class,服务器端也要添加该类

namespace WebApiInvoke {     /// <summary>     /// 后台程序发送HTTP请求数据的类     /// </summary>     class RequestDataModel     {         /// <summary>         /// 姓名         /// </summary>         public string DataName { get; set; }         /// <summary>         /// 性别         /// </summary>         public string DataSex { get; set; }         /// <summary>         /// 结果         /// </summary>         public string DataResult { get; set; }         /// <summary>         /// 年龄         /// </summary>         public int DataAge { get; set; }     } } 

2、服务端返回HTTP请求的数据class,客户端也要有

namespace ServiceTest {     /// <summary>     /// WebService 服务端返回的类     /// </summary>     public class WebServiceWriteBack     {         public bool Success { get; set; } = true;         public string Data { get; set; } = string.Empty;     } } 

二、“application/json”:

1、后台程序(客户端)发送HTTP请求(request.Method = “POST”、request.ContentType = “application/json”),

a.客户端代码:
namespace WebApiInvoke {     class HttpApiRequestHelper     {         /// <summary>         /// 使用HttpWebRequest发送一个POST请求          /// </summary>         /// <param name="url">请求的地址</param>         /// <param name="dto">发送的数据对象</param>         /// <returns></returns>         public static string HttpJsonPost(string url, object dto)         {             HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);              request.Method = "POST";             request.KeepAlive = false;             request.AllowAutoRedirect = true;             request.Accept = "application/json";             request.ContentType = "application/json";             string strContent = JsonConvert.SerializeObject(dto); //序列化为字符串,可以使用自己项目中封装的json方法             using (StreamWriter dataStream = new StreamWriter(request.GetRequestStream()))             {                 dataStream.Write(strContent);             }             //  获取服务器返回的响应体             HttpWebResponse response = (HttpWebResponse)request.GetResponse();             string encoding = response.ContentEncoding;             if (encoding == null || encoding.Length < 1)             {                 encoding = "UTF-8"; //默认编码               }             StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.GetEncoding(encoding));             string retString = reader.ReadToEnd();             return retString;         }    	} } 

服务器端通过Request.InputStream获取json数据,并做相应的处理;
需要NuGet程序包中安装Microsoft.AspNetCore.Mvc.WebApiCompatShim,并usingSystem.Web.Http;请添加图片描述

b.服务器端对应的代码
using Newtonsoft.Json; using System; using System.IO; using System.Web; using System.Web.Http;  namespace ServiceTest {     /// WebService 接口 通过Request请求获取json参数     class GetRequestDataHelper : ApiController     {         /// <summary>         /// 通过Request请求获取json参数         /// 对应request.ContentType = "application/json"         /// </summary>         /// <returns></returns>         public WebServiceWriteBack GetRequestJsonData()         {         	// 服务器端回写数据库的类             WebServiceWriteBack writeBack = new WebServiceWriteBack();             HttpContextBase context = Request.Properties["MS_HttpContext"] as HttpContextBase;             HttpRequestBase request = context.Request;              string data = string.Empty;             using (Stream stream = request.InputStream)// 读取Json数据             {                 stream.Position = 0;                 using (StreamReader streamReader = new StreamReader(stream))                 {                     data = streamReader.ReadToEnd();                 }             }             // 将Json数据转换为对象             RequestDataModel data1 = JsonConvert.DeserializeObject<RequestDataModel>(data);             #region 对传进来的 DataModel 进行处理 并对要回写的WebServiceWriteBack类进行赋值             if (string.IsNullOrEmpty(data1.DataSex))             {                 writeBack.Success = true;                 writeBack.Data = "成功了!";             }             #endregion              return writeBack;         }     } } 

三、表单:

1、传统的表单数据是"DataName=1&DataSex=dadada&DataResult=S201FR&DataAge=1"一个字符串中间用‘&’分割;

后台程序(客户端)发送HTTP请求(request.Method = “POST”、request.ContentType = “application/x-www-form-urlencoded”),

a.客户端代码:
        /// <summary>         /// HttpWebRequest Post请求         /// application/x-www-form-urlencoded         /// "DataName=1&DataSex=dadada&DataResult=S201FR&DataAge=1"         /// </summary>         /// <param name="postUrl">请求地址</param>         /// <param name="postData">请求参数(json格式请求数据时contentType必须指定为application/json)</param>         /// <param name="result">返回结果</param>         /// <param name="contentType">请求类型</param>         /// <returns>返回结果</returns>         public static bool WebHttpPost(string postUrl, string postData, out string result, string contentType = "application/x-www-form-urlencoded")         {             try             {                 Encoding encoding = Encoding.GetEncoding("gb2312");                 byte[] byteArray = encoding.GetBytes(postData);                  HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(postUrl);                 httpWebRequest.Method = "POST";                 httpWebRequest.ContentType = contentType;                 httpWebRequest.ContentLength = byteArray.Length;                 httpWebRequest.AllowAutoRedirect = true;                  using (Stream stream = httpWebRequest.GetRequestStream())                 {                     stream.Write(byteArray, 0, byteArray.Length); // 写入参数                                   } 				//  获取服务器返回的响应体                 HttpWebResponse httpWebResponse = httpWebRequest.GetResponse() as HttpWebResponse;                 using (Stream responseStream = httpWebResponse.GetResponseStream())                 {                     StreamReader streamReader = new StreamReader(responseStream, Encoding.GetEncoding("UTF-8"));                     result = streamReader.ReadToEnd(); // 请求返回的数据                     streamReader.Close();                 }                  return true;             }             catch (Exception ex)             {                 result = ex.Message;                 return false;             }         } 
b.服务器端通过Request.Form获取表单数据,并做相应的处理;
using Newtonsoft.Json; using System; using System.IO; using System.Web; using System.Web.Http;  namespace ServiceTest {         /// <summary>         /// 通过Request请求获取表单参数         /// 对应contentType = "application/x-www-form-urlencoded"和contentType =  "multipart/form-data"         /// </summary>         /// <returns></returns>          public WebServiceWriteBack GetRequestFromData()         {             // 服务器端回写数据库的类             WebServiceWriteBack writeBack = new WebServiceWriteBack();             HttpContextBase context = Request.Properties["MS_HttpContext"] as HttpContextBase;             HttpRequestBase request = context.Request;                          RequestDataModel data1 = new RequestDataModel()             {                 DataName = request.Form["DataName"]?.ToString(),                 DataSex = request.Form["DataSex"]?.ToString(),                 DataAge = Convert.ToInt32(request.Form["DataAge"]?.ToString()),                 DataResult = request.Form["DataResult"]?.ToString()             };             #region 对传进来的 DataModel 进行处理 并对要回写的WebServiceWriteBack类进行赋值             if (string.IsNullOrEmpty(data1.DataSex))             {                 writeBack.Success = true;                 writeBack.Data = "成功了!";             }             #endregion              return writeBack;         }     } }  

2、“multipart/form-data”

包含异步请求方法HttpPostAsync和HttpPostFromData方法

a.客户端代码,两个方法
using Newtonsoft.Json; using Newtonsoft.Json.Linq; using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Net; using System.Text;  namespace WebApiInvoke {     class HttpApiRequestHelper     {         /// <summary>         /// Async异步请求 POST         /// </summary>         /// <param name="urlStr">请求的地址</param>         /// <param name="jsonStr">Json字符串</param>         /// <returns></returns>         public static string HttpPostAsync(string urlStr, string jsonStr)         {             string content = "";             try             {                 Dictionary<string, string> map = JsonStringToKeyValuePairs(jsonStr);                  var mfdc = new System.Net.Http.MultipartFormDataContent();                 mfdc.Headers.Add("ContentType", "multipart/form-data");//声明头部                 foreach (string key in map.Keys)                 {                     mfdc.Add(new System.Net.Http.StringContent(map[key]), key);//参数, 内容在前,参数名称在后                 }                 var clientTask = new System.Net.Http.HttpClient().PostAsync(urlStr, mfdc);//发起异步请求                 clientTask.Wait();//等待请求结果                 if (clientTask.Result.IsSuccessStatusCode)                 {                     //请求正常                     var resultTask = clientTask.Result.Content.ReadAsStringAsync();//异步读取返回内容                     resultTask.Wait();//等读取返回内容                     content = resultTask.Result;//返回内容字符串                 }                 else                 {                     //请求异常                     content = "失败";                 }             }             catch (Exception ex)             {                 content = ex.Message;             }             return content;         }          /// <summary>         /// multipart/form-data POST请求         /// </summary>         /// <param name="url">请求的地址</param>         /// <param name="jsonStr">Json字符串</param>         /// <returns></returns>         public static string HttpPostFromData(string url, string jsonStr)         {             string content = "";             try             {                 string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x");                 byte[] boundarybytes = Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n");                 byte[] endbytes = Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n");                  HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);                 request.ContentType = "multipart/form-data; boundary=" + boundary;                 request.Method = WebRequestMethods.Http.Post;                 request.KeepAlive = true;                 request.Timeout = -1;                  CredentialCache credentialCache = new CredentialCache();                 credentialCache.Add(new Uri(url), "Basic", new NetworkCredential("user", "user"));                 request.Credentials = credentialCache;                  request.ServicePoint.Expect100Continue = false;                 Dictionary<string, string> map = JsonStringToKeyValuePairs(jsonStr);                 using (Stream stream = request.GetRequestStream())                 {                     //1.1 key/value                     string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}";                     if (map != null)                     {                         foreach (string key in map.Keys)                         {                             stream.Write(boundarybytes, 0, boundarybytes.Length);                             string formitem = string.Format(formdataTemplate, key, map[key]);                             byte[] formitembytes = Encoding.GetEncoding("UTF-8").GetBytes(formitem);                             stream.Write(formitembytes, 0, formitembytes.Length);                         }                     }                     stream.Write(endbytes, 0, endbytes.Length);                 }                 //2.WebResponse                 HttpWebResponse response = request.GetResponse() as HttpWebResponse;                 using (Stream responsestream = response.GetResponseStream())                 {                     using (StreamReader sr = new StreamReader(responsestream))                     {                         content = sr.ReadToEnd();                     }                 }             }             catch (Exception ex)             {                 content = ex.Message;             }             return content;         }          /// <summary>         /// JSON格式转Dictionary         /// </summary>         /// <param name="jsonStr"></param>         /// <returns></returns>         public static Dictionary<string, string> JsonStringToKeyValuePairs(string jsonStr)         {             char jsonBeginToken = '{';             char jsonEndToken = '}';              if (string.IsNullOrEmpty(jsonStr))             {                 return null;             }             //验证json字符串格式             if (jsonStr[0] != jsonBeginToken || jsonStr[jsonStr.Length - 1] != jsonEndToken)             {                 throw new ArgumentException("非法的Json字符串!");             }              var resultDic = new Dictionary<string, string>();             var jobj = JObject.Parse(jsonStr);             JsonOn(jobj, resultDic);             return resultDic;         }          private static Dictionary<string, string> JsonOn(JToken jobT, Dictionary<string, string> Dic)         {              //找出包含嵌套的字段列             if (jobT is JObject jobj && jobj.Properties().Count() > 0)             {                 foreach (var item in jobj.Properties())                 {                     JsonProperties(item, Dic);                 }             }             else             {                 Dic.Add(jobT.Path, jobT.ToString());                  return Dic;             }             return Dic;         }          private static Dictionary<string, string> JsonProperties(JProperty jobj, Dictionary<string, string> Dic)         {             return JsonOn(jobj.Value, Dic);         }      } } 
b. 服务器方法同1.b 这里不再赘述

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