小编典典

C＃如何正确发出http Web GET请求

我仍然对C＃还是陌生的，并且我正在尝试为此页面创建一个应用程序，当我收到通知（回答，评论等）时，它将告诉我。但是现在，我只是尝试对api进行简单的调用，以获取用户的数据。

我正在使用Visual Studio Express
2012构建C＃应用程序，现在（在此情况下）您输入用户ID，因此该应用程序将使用用户ID进行请求并显示此用户ID的统计信息。

这是我试图发出请求的代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
//Request library
using System.Net;
using System.IO;

namespace TestApplication
{
    class Connect
    {
        public string id;
        public string type;

        protected string api = "https://api.stackexchange.com/2.2/";
        protected string options = "?order=desc&sort=name&site=stackoverflow";

        public string request()
        {
            string totalUrl = this.join(id);

            return this.HttpGet(totalUrl);
        }

        protected string join(string s)
        {
            return api + type + "/" + s + options;
        }

        protected string get(string url)
        {
            try
            {
                string rt;

                WebRequest request = WebRequest.Create(url);

                WebResponse response = request.GetResponse();

                Stream dataStream = response.GetResponseStream();

                StreamReader reader = new StreamReader(dataStream);

                rt = reader.ReadToEnd();

                Console.WriteLine(rt);

                reader.Close();
                response.Close();

                return rt;
            }

            catch(Exception ex)
            {
                return "Error: " + ex.Message;
            }
        }
        public string HttpGet(string URI)
        {
            WebClient client = new WebClient();

            // Add a user agent header in case the 
            // requested URI contains a query.

            client.Headers.Add("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");

            Stream data = client.OpenRead(URI);
            StreamReader reader = new StreamReader(data);
            string s = reader.ReadToEnd();
            data.Close();
            reader.Close();

            return s;
        }
    }
}

该类是一个对象，只需解析用户ID并发出请求即可从表单中访问它。

我已经尝试了许多在google上查看过的示例，但不知道为什么我会一直使用此消息。

我是这种算法的新手，如果任何人都可以共享一本书或教程来展示如何做这种事情（解释每个步骤），我将不胜感激

阅读 2878

2020-05-19

共1个答案

小编典典

服务器有时会压缩其响应以节省带宽，当这种情况发生时，您需要在尝试读取响应之前对其进行解压缩。幸运的是，.NET框架可以自动执行此操作，但是，我们必须打开该设置。

这是如何实现此目的的示例。

string html = string.Empty;
string url = @"https://api.stackexchange.com/2.2/answers?order=desc&sort=activity&site=stackoverflow";

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
request.AutomaticDecompression = DecompressionMethods.GZip;

using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
using (Stream stream = response.GetResponseStream())
using (StreamReader reader = new StreamReader(stream))
{
    html = reader.ReadToEnd();
}

Console.WriteLine(html);

编辑 17/11/23

更新以抛出使用GET请求和POST异步的示例

得到

public string Get(string uri)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
    request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;

    using(HttpWebResponse response = (HttpWebResponse)request.GetResponse())
    using(Stream stream = response.GetResponseStream())
    using(StreamReader reader = new StreamReader(stream))
    {
        return reader.ReadToEnd();
    }
}

取得异步

public async Task<string> GetAsync(string uri)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
    request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;

    using(HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync())
    using(Stream stream = response.GetResponseStream())
    using(StreamReader reader = new StreamReader(stream))
    {
        return await reader.ReadToEndAsync();
    }
}

POST 在您希望使用其他HTTP方法（例如PUT，DELETE和ETC）时
包含参数method

public string Post(string uri, string data, string contentType, string method = "POST")
{
    byte[] dataBytes = Encoding.UTF8.GetBytes(data);

    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
    request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
    request.ContentLength = dataBytes.Length;
    request.ContentType = contentType;
    request.Method = method;

    using(Stream requestBody = request.GetRequestStream())
    {
        requestBody.Write(dataBytes, 0, dataBytes.Length);
    }

    using(HttpWebResponse response = (HttpWebResponse)request.GetResponse())
    using(Stream stream = response.GetResponseStream())
    using(StreamReader reader = new StreamReader(stream))
    {
        return reader.ReadToEnd();
    }
}

POST异步 在您希望使用其他HTTP方法（例如PUT，DELETE和ETC）时
包含参数method

public async Task<string> PostAsync(string uri, string data, string contentType, string method = "POST")
{
    byte[] dataBytes = Encoding.UTF8.GetBytes(data);

    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
    request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
    request.ContentLength = dataBytes.Length;
    request.ContentType = contentType;
    request.Method = method;

    using(Stream requestBody = request.GetRequestStream())
    {
        await requestBody.WriteAsync(dataBytes, 0, dataBytes.Length);
    }

    using(HttpWebResponse response = (HttpWebResponse)await request.GetResponseAsync())
    using(Stream stream = response.GetResponseStream())
    using(StreamReader reader = new StreamReader(stream))
    {
        return await reader.ReadToEndAsync();
    }
}

2020-05-19