Send Post request through HttpClient in C#

HttpClient in C# performs various types of transmission

We can see that although PostAsync has four overloaded functions, all of them accept HttpContent, and looking at the source code, we can see that HttpContent is an abstract class

Then it is impossible for us to directly create an instance of HttpContent, but we need to find its implementation class. After some research, we found the following four:

MultipartFormDataContent、FormUrlEncodedContent、StringContent、StreamContent

A comparison with the above summary will reveal the clues:

MultipartFormDataContent=》multipart/form-data

FormUrlEncodedContent=》application/x-www-form-urlencoded

StringContent=》application/json等

StreamContent=》binary

And as summarized above, FormUrlEncodedContent is just a special StringContent, the only difference is that you manually perform URL encoding before mediaType (this is purely guesswork, logically there should be no problem).

c# uses HttpClient's post, get method to transfer json

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using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;
using System.Timers;
using Newtonsoft.Json;
using System.Net.Http;
using System.IO;
using System.Net;
public class user
        {
            public string password;//密码hash
            public string account;//账户
        }

        static async void TaskAsync()
        {

            
            using (var client = new HttpClient())
            {
                
                try
                {
                    //序列化
                    user user = new user();
                    user.account = "zanllp";
                    user.password = "zanllp_pw";
                    var str = JsonConvert.SerializeObject(user);

                    HttpContent content =new StringContent(str);
                    content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");
                    HttpResponseMessage response = await client.PostAsync("http://255.255.255.254:5000/api/auth", content);//改成自己的
                    response.EnsureSuccessStatusCode();//用来抛异常的
                    string responseBody = await response.Content.ReadAsStringAsync();
                    Console.WriteLine(responseBody);
                }
                catch (Exception e)
                {
                    Console.WriteLine("\nException Caught!");
                    Console.WriteLine("Message :{0} ", e.Message);
                }
            }

            using (HttpClient client = new HttpClient())
            {
                try
                {
                    HttpResponseMessage response = await client.GetAsync("http://255.255.255.254:5000/api/auth");
                    response.EnsureSuccessStatusCode();//用来抛异常的
                    string responseBody = await response.Content.ReadAsStringAsync();
                    Console.WriteLine(responseBody);
                }
                catch (HttpRequestException e)
                {
                    Console.WriteLine("\nException Caught!");
                    Console.WriteLine("Message :{0} ", e.Message);
                }
            }
        }
 static void Main(string[] args)
        {
            TaskAsync();
            
            Console.ReadKey();
        }
 

在阿里云上的.Net Core on Linux

自己封装的类，我几乎所有的个人项目都用这个
using ICSharpCode.SharpZipLib.GZip;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;

/// <summary>
/// 基于HttpClient封装的请求类
/// </summary>
public class HttpRequest
{
    /// <summary>
    /// 使用post方法异步请求
    /// </summary>
    /// <param name="url">目标链接</param>
    /// <param name="json">发送的参数字符串，只能用json</param>
    /// <returns>返回的字符串</returns>
    public static async Task<string> PostAsyncJson(string url, string json)
    {
        HttpClient client = new HttpClient();
        HttpContent content = new StringContent(json);
        content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");
        HttpResponseMessage response = await client.PostAsync(url, content);
        response.EnsureSuccessStatusCode();
        string responseBody = await response.Content.ReadAsStringAsync();
        return responseBody;
    }

    /// <summary>
    /// 使用post方法异步请求
    /// </summary>
    /// <param name="url">目标链接</param>
    /// <param name="data">发送的参数字符串</param>
    /// <returns>返回的字符串</returns>
    public static async Task<string> PostAsync(string url, string data, Dictionary<string, string> header = null, bool Gzip = false)
    {
        HttpClient client = new HttpClient(new HttpClientHandler() { UseCookies = false });
        HttpContent content = new StringContent(data);
        if (header != null)
        {
            client.DefaultRequestHeaders.Clear();
            foreach (var item in header)
            {
                client.DefaultRequestHeaders.Add(item.Key, item.Value);
            }
        }
        HttpResponseMessage response = await client.PostAsync(url, content);
        response.EnsureSuccessStatusCode();
        string responseBody = "";
        if (Gzip)
        {
            GZipInputStream inputStream = new GZipInputStream(await response.Content.ReadAsStreamAsync());
            responseBody = new StreamReader(inputStream).ReadToEnd();
        }
        else
        {
            responseBody = await response.Content.ReadAsStringAsync();

        }
        return responseBody;
    }

    /// <summary>
    /// 使用get方法异步请求
    /// </summary>
    /// <param name="url">目标链接</param>
    /// <returns>返回的字符串</returns>
    public static async Task<string> GetAsync(string url, Dictionary<string, string> header = null, bool Gzip = false)
    {

        HttpClient client = new HttpClient(new HttpClientHandler() { UseCookies = false });
        if (header != null)
        {
            client.DefaultRequestHeaders.Clear();
            foreach (var item in header)
            {
                client.DefaultRequestHeaders.Add(item.Key, item.Value);
            }
        }
        HttpResponseMessage response = await client.GetAsync(url);
        response.EnsureSuccessStatusCode();//用来抛异常的
        string responseBody = "";
        if (Gzip)
        {
            GZipInputStream inputStream = new GZipInputStream(await response.Content.ReadAsStreamAsync());
            responseBody = new StreamReader(inputStream).ReadToEnd();
        }
        else
        {
            responseBody = await response.Content.ReadAsStringAsync();

        }
        return responseBody;
    }

    /// <summary>
    /// 使用post返回异步请求直接返回对象
    /// </summary>
    /// <typeparam name="T">返回对象类型</typeparam>
    /// <typeparam name="T2">请求对象类型</typeparam>
    /// <param name="url">请求链接</param>
    /// <param name="obj">请求对象数据</param>
    /// <returns>请求返回的目标对象</returns>
    public static async Task<T> PostObjectAsync<T, T2>(string url, T2 obj)
    {
        String json = JsonConvert.SerializeObject(obj);
        string responseBody = await PostAsyncJson(url, json); //请求当前账户的信息
        return JsonConvert.DeserializeObject<T>(responseBody);//把收到的字符串序列化
    }

    /// <summary>
    /// 使用Get返回异步请求直接返回对象
    /// </summary>
    /// <typeparam name="T">请求对象类型</typeparam>
    /// <param name="url">请求链接</param>
    /// <returns>返回请求的对象</returns>
    public static async Task<T> GetObjectAsync<T>(string url)
    {
        string responseBody = await GetAsync(url); //请求当前账户的信息
        return JsonConvert.DeserializeObject<T>(responseBody);//把收到的字符串序列化
    }
}
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版权声明：本文为CSDN博主「luckyone906」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/u011555996/article/details/116721769

C# uses HttpClient to make http GET/POST requests

using System;
using System.Collections.Generic;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;
namespace HTTPRequest
{
    class Program
    {
        static void Main(string[] args)
        {
           
            HttpClient httpClient = new HttpClient();
            Task<byte[]> task0= httpClient.GetByteArrayAsync("http://127.0.0.1");
            task0.Wait();
           // while (!task0.IsCompletedSuccessfully) { };
            byte[] bresult=task0.Result;
            string sresult = System.Text.Encoding.Default.GetString(bresult);
            Console.WriteLine(sresult);
          //  Console.ReadLine();
            -------
            HttpClient httpClient0 = new HttpClient();
            List<KeyValuePair<string, string>> param = new List<KeyValuePair<string, string>>();
            param.Add(new KeyValuePair<string, string>("xx", "xx"));
           Task<HttpResponseMessage> responseMessage  =httpClient0.PostAsync("http://localhost:1083/Home/Test", new FormUrlEncodedContent(param));
            responseMessage.Wait();
           Task<string> reString= responseMessage.Result.Content.ReadAsStringAsync();
            reString.Wait();
            Console.WriteLine(reString.Result);
            Console.ReadLine();
 
        }
    }
}
————————————————
版权声明：本文为CSDN博主「luckyone906」的原创文章，遵循CC 4.0 BY-SA版权协议，转载请附上原文出处链接及本声明。
原文链接：https://blog.csdn.net/u011555996/article/details/116721769