public class DataContext : DbContext
{
    //【注意】連接字符串一定要加 sslmode=none 
    string str = @"Data Source=;Database=;User ID=;Password=;pooling=true;CharSet=utf8;port=3306;sslmode=none";
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) =>
        optionsBuilder.UseMySQL(str);

    //下面就可以添加要加入數(shù)據(jù)庫的實體了
    //public DbSet<Message> Messages { get; set; }
}

{
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "ConnectionStrings": { "SqlServerConnection": "Data Source=;Database=;User ID=;Password=;pooling=true;CharSet=utf8;port=3306;sslmode=none" }
}

var connection = Configuration.GetConnectionString("SqlServerConnection");
services.AddDbContext<DataContext>(options => options.UseMySQL(connection));

var Socket = new WebSocket(url);//創(chuàng)建 WebSocket 對象

Socket.onopen = function(){  }

Socket.onmessage  //客戶端接收服務(wù)端數(shù)據(jù)時觸發(fā)
Socket.onerror    //通信發(fā)生錯誤時觸發(fā)
Socket.onclose    //連接關(guān)閉時觸發(fā)

Socket.send()   //使用連接發(fā)送數(shù)據(jù)
Socket.close()  //關(guān)閉連接

Socket.readyState
0 - 表示連接尚未建立。
1 - 表示連接已建立，可以進行通信。
2 - 表示連接正在進行關(guān)閉。
3 - 表示連接已經(jīng)關(guān)閉或者連接不能打開。

/// <summary>
/// 請求
/// </summary>
/// <param name="app"></param>
public static void Map(IApplicationBuilder app)
{
    app.UseWebSockets(); //【注意】需要 nuget   導(dǎo)入 Microsoft.AspNetCore.WebSockets.Server
    app.Use(Acceptor);
}

/// <summary>
/// 接收請求
/// </summary>
/// <param name="httpContext"></param>
/// <param name="n"></param>
/// <returns></returns>
static async Task Acceptor(HttpContext httpContext, Func<Task> n)
{

app.Map("/ws", SocketHandler.Map);   //傳入我們剛才新建的靜態(tài)方法Map

//建立連接
var socket = await httpContext.WebSockets.AcceptWebSocketAsync();
//等待接收數(shù)據(jù)
await socket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
//發(fā)送消息
await socket.SendAsync(arraySegment, WebSocketMessageType.Text, true, CancellationToken.None);

using (HttpClient http = new HttpClient())
{
    var htmlString = await http.GetStringAsync(url);
    HtmlParser htmlParser = new HtmlParser();
    var jobInfos = htmlParser.Parse(htmlString)
        .QuerySelectorAll(".newlist_list_content table")
        .Where(t => t.QuerySelectorAll(".zwmc a").FirstOrDefault() != null)
        .Select(t => new JobInfo()
        {
            PositionName = t.QuerySelectorAll(".zwmc a").FirstOrDefault().TextContent,
            CorporateName = t.QuerySelectorAll(".gsmc a").FirstOrDefault().TextContent,
            Salary = t.QuerySelectorAll(".zwyx").FirstOrDefault().TextContent,
            WorkingPlace = t.QuerySelectorAll(".gzdd").FirstOrDefault().TextContent,
        .ToList();
    return jobInfos;
}

server {
    listen 80;
    server_name www.haojima.net;           #對應(yīng)的域名
    root /home/projects/messagBoard;       #程序路徑
    location / {
        proxy_pass http://localhost:5000;  #內(nèi)網(wǎng)端口
        proxy_http_version 1.1; 
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection keep-alive;
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
        proxy_set_header X-real-ip $remote_addr;
        
        proxy_set_header Upgrade $http_upgrade;   
    }
}

[program:MessageBoard]
command=dotnet MessageBoard.dll        ; 運行程序的命令
directory= /home/projects/messagBoard/ ; 命令執(zhí)行的目錄
autorestart=true                    ; 程序意外退出是否自動重啟
stderr_logfile=/var/log/WebApplication1.err.log ; 錯誤日志文件
stdout_logfile=/var/log/WebApplication1.out.log ; 輸出日志文件
environment=ASPNETCORE_ENVIRONMENT=Production ; 進程環(huán)境變量
user=root ; 進程執(zhí)行的用戶身份
stopsignal=INT

server {
    listen 80;
    server_name www.haojima.net;
    root /home/projects/messagBoard;
    location / {
        proxy_pass http://localhost:5000;
        proxy_http_version 1.1; 
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection keep-alive;
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
        proxy_set_header X-real-ip $remote_addr;     # 新添加
    }
}

var ip = HttpContext.Request.Headers["X-real-ip"].FirstOrDefault();

server {
    listen 80;
    server_name job.haojima.net;
    root /home/projects/jobWanted;
    location / {
        proxy_pass http://localhost:5002;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection keep-alive;
        proxy_set_header Host $host;
        proxy_cache_bypass $http_upgrade;
        proxy_set_header X-real-ip $remote_addr;
        proxy_set_header Upgrade $http_upgrade;     # 新增
        #proxy_set_header Connection "upgrade";      # 新增 
        proxy_set_header Connection $http_connection;  #ws和post同時使用  https://github.com/aspnet/KestrelHttpServer/issues/1263
    }
}

Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);//注冊編碼提供程序

var htmlBytes = await http.GetByteArrayAsync(url);
var htmlString = Encoding.GetEncoding("GBK").GetString(htmlBytes);

{
  "server.urls": "http://*:5002"
}

public static void Main(string[] args)
{
    var config = new ConfigurationBuilder()
          .SetBasePath(Directory.GetCurrentDirectory())
          .AddJsonFile("hosting.json", optional: true)
          .Build();

    var host = new WebHostBuilder()
        .UseKestrel()
        .UseConfiguration(config)
        .UseContentRoot(Directory.GetCurrentDirectory())
        .UseIISIntegration()
        .UseStartup<Startup>()
        .UseApplicationInsights()
        .Build();

    host.Run();
}

using (HttpClient http = new HttpClient())
{
    var url = "https://www.lagou.com/zhaopin/Java/?labelWords=label";
    var htmlString = await http.GetStringAsync(url);
}

170819搞定

https://github.com/zhaopeiym/JobWanted/blob/master/JobWanted/Controllers/JobsController.cs#L211

//拉勾網(wǎng) 后臺檢測了user-agent、X-Requested-With、Referer還會檢測list_是否有參數(shù)
http.DefaultRequestHeaders.Add("Referer", "https://www.lagou.com/jobs/list_.net");
http.DefaultRequestHeaders.Add("user-agent", "Mozilla/5.0");
http.DefaultRequestHeaders.Add("X-Requested-With", "XMLHttpRequest");