（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
    @{
       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>