(十四)配置的热更新

Posted 2020-11-06 liu_xh

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

•  1 @using Microsoft.Extensions.Options
   2 @inject IOptionsSnapshot<OptionsBindSample.Class> ClassAccesser //原来的IOptions改成IOptionsSnapshot
   3 @{
   4     ViewData["Title"] = "Index";
   5 }
   6 
   7 <h2>Index</h2>
   8 
   9 <div>
  10     @foreach(var stu in ClassAccesser.Value.Students)
  11     {
  12         <span>Name:@stu.Name</span>
  13         <span>Age:@stu.Age</span>
  14 
  15     }
  16 </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

•  1         public static void Main(string[] args)
   2         {
   3             BuildWebHost(args).Run();
   4         }
   5 
   6         /// <summary>
   7         /// 启动的时候默认会读取appsettings.json文件
   8         /// </summary>
   9         /// <param name="args"></param>
  10         /// <returns></returns>
  11         public static IWebHost BuildWebHost(string[] args) =>
  12             WebHost.CreateDefaultBuilder(args)//只要配置文件名称是appsettings.json。CreateDefaultBuilder会读取appsettings.json
  13             .ConfigureAppConfiguration((config)=> {
  14                 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
  15             })
  16             .UseStartup<Startup>()
  17             .Build();