asp.net core 依赖注入问题

最近.net core可以跨平台了，这是一个伟大的事情，为了可以赶上两年以后的跨平台部署大潮，我也加入到了学习之列。今天研究的是依赖注入，但是我发现一个问题，困扰我很久，现在我贴出来，希望可以有人帮忙解决或回复一下。

背景：我测试.net自带的依赖注入生命周期，一共三个：Transient、Scope、Single三种，通过一个GUID在界面展示，但是我发现scope和single的每次都是相同的，并且single实例的guid值每次都会改变。

通过截图可以看到scope和Single每次浏览器刷新都会改变，scope改变可以理解，就是每次请求都会改变。但是single 每次都改变就不对了。应该保持一个唯一值才对。

Program.cs代码：启动代码

 namespace CoreStudy
 {
     public class Program
     {
         public static void Main(string[] args)
         {
             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
             var host = new WebHostBuilder()
                 .UseKestrel()//使用服务器serve
                 .UseContentRoot(Directory.GetCurrentDirectory())
                 .UseIISIntegration()//使用IIS
                 .UseStartup<Startup>()//使用起始页
                 .Build();//IWebHost

             host.Run();//构建用于宿主应用程序的IWebHost
             //然后启动它来监听传入的HTTP请求
         }
     }
 }

Startup.cs 文件代码

 namespace CoreStudy
 {
     public class Startup
     {
         public Startup(IHostingEnvironment env, ILoggerFactory logger)
         {
             var builder = new ConfigurationBuilder()
                 .SetBasePath(env.ContentRootPath)
                 .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                 .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                 .AddEnvironmentVariables();
             builder.AddInMemoryCollection();

         }
         // 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 http://go.microsoft.com/fwlink/?LinkID=398940
         public void ConfigureServices(IServiceCollection services)
         {//定义服务
             services.AddMvc();
             services.AddLogging();
             services.AddTransient<IPersonRepository, PersonRepository>();
             services.AddTransient<IGuidTransientAppService, TransientAppService>();

             services.AddScoped<IGuidScopeAppService, ScopeAppService>();

             services.AddSingleton<IGuidSingleAppService, SingleAppService>();
         }

         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
         public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory, IApplicationLifetime appLifetime)
         {//定义中间件

             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
                 app.UseBrowserLink();
                 app.UseDatabaseErrorPage();

             }
             else
             {
                 app.UseExceptionHandler("/Home/Error");
             }
             app.UseStaticFiles();
             //app.UseStaticFiles(new StaticFileOptions() {
             //      FileProvider=new PhysicalFileProvider(Path.Combine(Directory.GetCurrentDirectory(),@"staticFiles")),
             //       RequestPath="/staticfiles"
             // });
             //默认路由设置
             app.UseMvc(routes =>
             {
                 routes.MapRoute(name: "default", template: "{controller=Person}/{action=Index}/{id?}");
             });

         }
     }
 }

请注意22-26行，注册了三种不同生命周期的实例，transientService、scopeService以及singleService。

对应的接口定义：

 namespace CoreStudy
 {
     public interface IGuideAppService
     {
         Guid GuidItem();
     }
     public interface IGuidTransientAppService:IGuideAppService
     { }
     public interface IGuidScopeAppService:IGuideAppService
     { }
     public interface IGuidSingleAppService:IGuideAppService
     { }

 }

 namespace CoreStudy
 {
     public class GuidAppService : IGuideAppService
     {
         private readonly Guid item;
         public GuidAppService()
         {
             item = Guid.NewGuid();
         }
         public Guid GuidItem()
         {
             return item;
         }

     }
     public class TransientAppService:GuidAppService,IGuidTransientAppService
     {

     }

     public class ScopeAppService:GuidAppService,IGuidScopeAppService
     { }
     public class SingleAppService:GuidAppService,IGuidSingleAppService
     { }
 }

代码很简单，只是定义了三种不同实现类。

控制器中 通过构造函数注入方式注入：

 namespace CoreStudy.Controllers
 {
     /// <summary>
     /// 控制器方法
     /// </summary>
     public class PersonController : Controller
     {
         private readonly IGuidTransientAppService transientService;
         private readonly IGuidScopeAppService scopedService;
         private readonly IGuidSingleAppService singleService;

         private IPersonRepository personRepository = null;
         /// <summary>
         /// 构造函数
         /// </summary>
         /// <param name="repository"></param>
         public PersonController(IGuidTransientAppService trsn, IGuidScopeAppService scope, IGuidSingleAppService single)
         {
             this.transientService = trsn;
             this.scopedService = scope;
             this.singleService = single;
         }

         /// <summary>
         /// 主页方法
         /// </summary>
         /// <returns></returns>
         public IActionResult Index()
         {
             ViewBag.TransientService = this.transientService.GuidItem();

             ViewBag.scopeService = this.scopedService.GuidItem();

             ViewBag.singleservice = this.scopedService.GuidItem();

             return View();
         }

     }
 }

控制器对应的视图文件Index.cshtm

 @{
     ViewData["Title"] = "Person Index";
     Layout = null;
 }

 <form asp-controller="person"  method="post" class="form-horizontal" role="form">
      <h4>创建账户</h4>
     <hr />
    <div class="row">
        <div class="col-md-4">
            <span>TransientService:</span>
            @ViewBag.TransientService
        </div>
    </div>
     <div class="row">
         <span>Scope</span>
         @ViewBag.ScopeService
     </div>
     <div class="row">
         <span>Single</span>
         @ViewBag.SingleService
     </div>
     <div class="col-md-4">
         @await Component.InvokeAsync("Greeting");
     </div>
 </form>

其他无关代码就不粘贴了，希望各位能给个解释，我再看一下代码，是否哪里需要特殊设置。

答案在PersonController 类的 35行，此问题主要是为了能够更好的理解依赖注入

.Net Core来了，我们又可以通过学习来涨工资了。