(十四)配置的热更新

这一节演示下配置的热更新，即不用重启网站，更改配置文件的信息，网站也能同步更改。还是继续沿用OptionsBindSample

• 实现也比较简单，改下Index.cshtml

• @using Microsoft.Extensions.Options
  @inject IOptionsSnapshot<OptionsBindSample.Class> ClassAccesser //原来的IOptions改成IOptionsSnapshot
  @{
      ViewData["Title"] = "Index";
  }
  
  <h2>Index</h2>
  
  <div>
      @foreach(var stu in ClassAccesser.Value.Students)
      {
          <span>Name:@stu.Name</span>
          <span>Age:@stu.Age</span>
  
      }
  </div>

  实现原理看https://github.com/aspnet/MetaPackages/blob/dev/src/Microsoft.AspNetCore/WebHost.cs，162行

• 如果要禁用配置热更新
• Program.cs

•         public static void Main(string[] args)
          {
              BuildWebHost(args).Run();
          }
  
          /// <summary>
          /// 启动的时候默认会读取appsettings.json文件
          /// </summary>
          /// <param name="args"></param>
          /// <returns></returns>
          public static IWebHost BuildWebHost(string[] args) =>
              WebHost.CreateDefaultBuilder(args)//只要配置文件名称是appsettings.json。CreateDefaultBuilder会读取appsettings.json
              .ConfigureAppConfiguration((config)=> {
                  config.AddJsonFile("appsettings.json",false,true);//这里第三个参数reloadOnChange为false就是禁止热更新,否则就是允许热更新
              })
              .UseStartup<Startup>()
              .Build();