• 繼續上一節的，接下來用Options或者Bind把json文件裏的配置轉成C#的實體，相互之間映射起來。首先新建一個asp.net core mvc項目OptionsBindSample
• Startup.cs，這裏用依賴註入把Configuration加進來

• 1         public IConfiguration Configuration { get; set; }
  2 
  3         public Startup(IConfiguration configuration)
  4         {
  5             this.Configuration = configuration;
   
  6         }

• 再建立一個Class.cs

•  1 public class Class
   2         {
   3             public int ClassNo { get; set; }
   4             public string ClassDesc { get; set; }
   5             public List<Student> Students { get; set; }
   6         }
   7 
   8         public class Student
   9         {
  10             public
   
   string Name { get; set; }
  11             public string Age { get; set; }
  12         }

• 再建一個appsettings.json(名稱一定要叫這個，因為在Program.cs中WebHost.CreateDefaultBuilder(args)會默認讀取appsettings.json文件)

•  1 {
   2   "ClassNo": "1",
   3   "ClassDesc": "ASP.NET Core 101",
   4   "Students": [
   5     {
   6       "name
   
  ": "liuxh",
   7       "age": "31"
   8     },
   9     {
  10       "name": "linhj",
  11       "age": "31"
  12     },
  13     {
  14       "name": "liuxy",
  15       "age": "7"
  16 
  17 
  18 
  19     },
  20     {
  21       "name": "liuss",
  22       "age": "1"
  23     }
  24   ]
  25 
  26 }

• 最後Starup.cs代碼是這樣的

•         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)
          {
              
          }
  
          // 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.Run(async (context) =>
              {
                  var myClass = new Class();
                  Configuration.Bind(myClass);//把配置文件的信息和對象映射起來
  
                  await context.Response.WriteAsync($"ClassNo:{myClass.ClassNo}");
                  await context.Response.WriteAsync($"ClassDesc:{myClass.ClassDesc}");
                  await context.Response.WriteAsync($"{myClass.Students.Count} Students");
  
              }); 
          }

• 最後啟動網站

（十二）Bind讀取配置到C#實例