C# WebRequest GET/POST request

1：使用WebRequest向服务器发送GET请求，获取服务器的响应

1. 创建请求对象

2. 获取web响应

3. 获取web响应流

4.读取Web 流数据

完整代码如下：

    var url ="http://webcode.me";//"http://www.baidu.com";var request = WebRequest.Create(url);request.Method = "GET";using (var webResponse = request.GetResponse()){using (var webStream = webResponse.GetResponseStream()){using (var reader = new StreamReader(webStream)){var data = reader.ReadToEnd();Console.WriteLine(data);}}}

输出：

<meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>My html page</title>

<p>Today is a beautiful day. We go swimming and fishing.</p><p>Hello there. How are you?</p>

2：使用WebRequest向服务器发送POST请求，获取服务器的响应

1. 创建Web请求对象

2. 指定POST方法

创建POST数据对象
将数据对象序列化为JSON字符串

5. 再将Json字符串转换为字节数组

6. 指定请求ContentType类型

7. 获取请求流对象

8. 将转换后的字节数组写入到请求流中

9. 获取请求的响应

读取响应流中的数据

完整代码如下：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using Newtonsoft.Json;

using System.Net;

using System.Net.Http;

using System.IO;

namespace _02_HTTP_POST

{

//HTTP POST//The HTTP POST method sends data to the server.//It is often used when uploading a file or when submitting a completed web form.class Program{//C# POST request with WebRequest//creates a POST request with WebRequest.static void Main(string\[\] args){var url = "https://httpbin.org/post"; //发POST请求的服务器地址var request = WebRequest.Create(url);request.Method = "POST";var user = new User("John Doe", "gardener");var json = JsonConvert.SerializeObject(user);byte\[\] byteArray = Encoding.UTF8.GetBytes(json);//序列化user对象为Json字符串，再将Json字符串转为字节数组request.ContentType = "application/json";//request.ContentType = "application/x-www-form-urlencoded";//默认地，表单数据会编码为 "application/x-www-form-urlencoded"。//就是说，在发送到服务器之前，所有字符都会进行编码（空格转换为 "+" 加号，特殊符号转换为 ASCII HEX 值）。request.ContentLength = byteArray.Length;using (var reqStream = request.GetRequestStream())//获取请求流对象{reqStream.Write(byteArray, 0, byteArray.Length);//将POST的内容传入到请求流using (var response = request.GetResponse())// 获取响应的对象{Console.WriteLine(((HttpWebResponse)response).StatusDescription);// 响应状态using (var respStream = response.GetResponseStream())// 从响应流中读取数据{using (var reader = new StreamReader(respStream)){string data = reader.ReadToEnd();Console.WriteLine(data);}}}}}}class User{public string Name { get; set; }public string Occupation { get; set; }public User(string name, string occupation){Name = name;Occupation = occupation;}public override string ToString(){return $"{Name}: {Occupation}";}}

}

输出：

{

“args”: {},

“data”: “{\“Name\”:\“John Doe\”,\“Occupation\”:\“gardener\”}”,

“files”: {},

“form”: {},

“headers”: {

"Content-Length": "43","Content-Type": "application/json","Host": "httpbin.org","X-Amzn-Trace-Id": "Root=1-61aea836-517d25d562b9453c66922bab"

“json”: {

"Name": "John Doe","Occupation": "gardener"

“origin”: “180.161.88.74”,

“url”: “https://httpbin.org/post”

}

改变request.ContentType = “application/x-www-form-urlencoded”;

输出：

{

“args”: {},

“data”: “”,

“files”: {},

“form”: {

"{\\"Name\\":\\"John Doe\\",\\"Occupation\\":\\"gardener\\"}": ""

“headers”: {

"Content-Length": "43","Content-Type": "application/x-www-form-urlencoded","Host": "httpbin.org","X-Amzn-Trace-Id": "Root=1-61aea885-2ec9f6f639d59dba53b244ad"

“json”: null,

“origin”: “180.161.88.74”,

“url”: “https://httpbin.org/post”

}

差异：