（十三）在ASP.NET CORE中使用Options

• 这一节介绍Options方法，继续在OptionsBindSample项目下。
• 在项目中添加一个Controllers文件夹，文件夹添加一个HomeController控制器
• HomeController.cs

•         private readonly Class _myClass;
  
          public HomeController(IOptions<Class> classAccesser)//IOptions的方法注入
          {
              this._myClass = classAccesser.Value;
          } 
  
          public IActionResult Index()
          {
              return View(_myClass);
          }

• 在项目中添加一个Views文件夹，文件夹中添加一个Home文件夹（这和ASP.NET MVC一样）,Home文件夹下添加一个Index.cshtml

• @model OptionsBindSample.Class
   3 @{
      ViewData["Title"] = "Index";
  }
  
  <h2>Index</h2>
  
  <div>
      @foreach(var stu in Model.Students)
      {
          <span>Name:@stu.Name</span>
          <span>Age:@stu.Age</span>
  
      }
  </div>

• 此时StartUp.cs应该改成这样

•         public IConfiguration Configuration { get; set; }
  
          public Startup(IConfiguration configuration)
          {
              this.Configuration = configuration;
          }
  
          // This method gets called by the runtime. Use this method to add services to the container.
          // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
          public void ConfigureServices(IServiceCollection services)
          {
              services.Configure<Class>(Configuration);
  
              services.AddMvc();
          }
  
          // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
          public void Configure(IApplicationBuilder app, IHostingEnvironment env)
          {
              if (env.IsDevelopment())
              {
                  app.UseDeveloperExceptionPage();
              }
  
              app.UseMvcWithDefaultRoute();
          }

也可以不用在Controller中依赖注入，而在视图中注入，改成如下：

HomeController.cs

        public IActionResult Index()
        {
3             return View();
        }

Index.cshtml:

@using Microsoft.Extensions.Options
@inject IOptions<OptionsBindSample.Class> ClassAccesser
@{
    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>