在C#中使用HttpWebRequest类是用于发送HTTP请求的类，它属于System.Net命名空间。通过HttpWebRequest，你可以使用不同的请求方法（例如GET、POST、PUT、DELETE等）来与Web服务器进行交互。1. GET请求
GET请求通常用于请求服务器上的数据，不修改服务器上的资源。
引用
using System.IO;using System.Net;using System.Threading.Tasks;
//直接返回字符串public static string HttpGet(string url){ Encoding encoding = Encoding.UTF8; HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.Method = "GET"; request.Accept = "text/html, application/xhtml+xml, */*"; request.ContentType = "application/json"; HttpWebResponse response = (HttpWebResponse)request.GetResponse(); using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8)) { return reader.ReadToEnd(); }}
// 直接读取文件流public static string HttpGet(string url){ HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url); req.Method = "Get"; try { using (WebResponse wr = req.GetResponse()) { HttpWebResponse response = wr as HttpWebResponse; Stream stream = response.GetResponseStream(); //读取到内存 MemoryStream ms = new MemoryStream(); byte[] buffer = new byte[1024]; while (true) { int sz = stream.Read(buffer, 0, 1024); if (sz == 0) break; ms.Write(buffer, 0, sz); } string content = Convert.ToBase64String(ms.ToArray()); return content; } } catch (Exception ex) { return null; }}
2. POST请求
POST请求通常用于向服务器提交数据，如表单数据或JSON数据。
application/json
//Postpublic static string HttpPost(string url, string body){ Encoding encoding = Encoding.UTF8; HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.Method = "POST"; request.Accept = "text/html, application/xhtml+xml, */*"; request.ContentType = "application/json"; byte[] buffer = encoding.GetBytes(body); request.ContentLength = buffer.Length; request.GetRequestStream().Write(buffer, 0, buffer.Length); HttpWebResponse response = (HttpWebResponse)request.GetResponse(); using (StreamReader reader = new StreamReader(response.GetResponseStream(), Encoding.UTF8)) { return reader.ReadToEnd(); }}
application/x-www-form-urlencoded
public static string PostUrlFormUrlencoded(string url, string postData){ string result = ""; try { HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
req.Method = "POST";
req.ContentType = "application/x-www-form-urlencoded";
byte[] data = Encoding.UTF8.GetBytes(postData);
req.ContentLength = data.Length;
using (Stream reqStream = req.GetRequestStream()) { reqStream.Write(data, 0, data.Length);
reqStream.Close(); }
HttpWebResponse resp = (HttpWebResponse)req.GetResponse();
Stream stream = resp.GetResponseStream();
//获取响应内容 using (StreamReader reader = new StreamReader(stream, Encoding.UTF8)) { result = reader.ReadToEnd(); } } catch (Exception e) { Console.WriteLine("发送请求出错：" + e.Message); }
return result;}
multipart/form-data
public static string HttpPost(string url, NameValueCollection kVDatas = null, JObject headers = null, string method = WebRequestMethods.Http.Post, int timeOut = -1){ 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)WebRequest.Create(url); request.ContentType = "multipart/form-data; boundary=" + boundary; request.Method = "POST"; request.KeepAlive = true; request.Timeout = timeOut; if (headers != null) { IEnumerable<JProperty> properties = headers.Properties(); foreach (JProperty item in properties) { request.Headers.Add(item.Name, item.Value.ToString()); } }
CredentialCache credentialCache = new CredentialCache { { new Uri(url), "Basic", new NetworkCredential("member", "secret") } }; request.Credentials = credentialCache;
request.ServicePoint.Expect100Continue = false; using (Stream stream = request.GetRequestStream()) { string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}"; if (kVDatas != null) { foreach (string key in kVDatas.Keys) { stream.Write(boundarybytes, 0, boundarybytes.Length); string formitem = string.Format(formdataTemplate, key, kVDatas[key]); byte[] formitembytes = Encoding.GetEncoding("UTF-8").GetBytes(formitem); stream.Write(formitembytes, 0, formitembytes.Length); } } stream.Write(endbytes, 0, endbytes.Length); } HttpWebResponse response = (HttpWebResponse)request.GetResponse(); using (StreamReader stream = new StreamReader(response.GetResponseStream())) { return stream.ReadToEnd(); }
} catch (Exception e) {
Console.WriteLine(e.Message); return e.Message; }}
上传文件
public static string HttpUploadFile(string url, string filePath, string fileName, string paramName, string contentType, NameValueCollection nameValueCollection){ string boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x"); byte[] boundarybytes = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "\r\n"); HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url); request.ContentType = "multipart/form-data; boundary=" + boundary; request.Method = "POST"; request.KeepAlive = true; request.Credentials = CredentialCache.DefaultCredentials; Stream requestStream = request.GetRequestStream(); string formdataTemplate = "Content-Disposition: form-data; name=\"{0}\"\r\n\r\n{1}"; foreach (string key in nameValueCollection.Keys) { requestStream.Write(boundarybytes, 0, boundarybytes.Length); string formitem = string.Format(formdataTemplate, key, nameValueCollection[key]); byte[] formitembytes = System.Text.Encoding.UTF8.GetBytes(formitem); requestStream.Write(formitembytes, 0, formitembytes.Length); } requestStream.Write(boundarybytes, 0, boundarybytes.Length); string header = string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: {2}\r\n\r\n", paramName, fileName, contentType); byte[] headerbytes = Encoding.UTF8.GetBytes(header); requestStream.Write(headerbytes, 0, headerbytes.Length); FileStream fileStream = new FileStream(filePath, FileMode.Open, FileAccess.Read); byte[] buffer = new byte[4096]; int bytesRead = 0; while ((bytesRead = fileStream.Read(buffer, 0, buffer.Length)) != 0) { requestStream.Write(buffer, 0, bytesRead); } fileStream.Close(); byte[] trailer = System.Text.Encoding.ASCII.GetBytes("\r\n--" + boundary + "--\r\n"); requestStream.Write(trailer, 0, trailer.Length); requestStream.Close(); WebResponse webResponse = null; try { webResponse = request.GetResponse(); Stream responseStream = webResponse.GetResponseStream(); StreamReader streamReader = new StreamReader(responseStream); string result = streamReader.ReadToEnd(); return result; } catch (Exception ex) { if (webResponse != null) { webResponse.Close(); webResponse = null; } return null; } finally { request = null; }}
3. PUT请求
PUT请求用于上传文件或修改服务器上的资源。
public static void HttpPUT(){ HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://example.com/api/data"); request.Method = "PUT"; request.ContentType = "application/json"; // 或者其他适当的MIME类型，如 "text/xml" 或 "image/jpeg" 等
using (var postData = new StreamWriter(request.GetRequestStream())) { postData.Write(JsonConvert.SerializeObject(new { key1 = "value1", key2 = "value2" })); // 发送JSON数据示例 }
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse()) { using (Stream responseStream = response.GetResponseStream()) { using (StreamReader reader = new StreamReader(responseStream)) { string responseText = reader.ReadToEnd(); Console.WriteLine(responseText); } } }}
4. DELETE请求
DELETE请求用于请求删除指定的资源。
public static void HttpDELETE(){ HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://example.com/api/data/123"); request.Method = "DELETE"; using (HttpWebResponse response = (HttpWebResponse)request.GetResponse()) { Console.WriteLine("Resource deleted with status: " + response.StatusCode); }}
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该文章在 2025/2/17 13:06:35 编辑过
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