asp.net-core - 如何在 Asp.net 核心服务类中调用 View 组件？

Question

我需要在服务类(不是 Controller )中调用 View 组件。我的目标是将 View 组件呈现为字符串，然后处理 HtmlString .

我可以在 ActionContext 的 Controller 中找到渲染 View 组件的帮助。可用，但我无法从 Controller 调用我的服务。请问有什么帮助吗？我很高兴使用 Mock 和默认依赖注入(inject)。

目前，我正在使用 mvc 6 beta 2。这是我类(class)的代码

public class MyClass
{
    Microsoft.AspNet.Mvc.DefaultViewComponentHelper viewComponentHelper = null;
    Microsoft.AspNet.Mvc.Razor.RazorView razorView = null;

    public MyClass(IViewComponentSelector selector, IViewComponentInvokerFactory factory,
        IRazorPageFactory razorPageFactory, IRazorViewEngine razorViewEngine, IRazorPageActivator pageActivator,
        IViewStartProvider viewStartProvider)
    {
        viewComponentHelper = new DefaultViewComponentHelper(selector, factory);
        razorView = new RazorView(razorViewEngine, pageActivator, viewStartProvider, null, true);
    }

    public void MyAction
    {

        var view = new Mock<IView>().Object;    

        var actionContext = new ActionContext(new RouteContext(new DefaultHttpContext()), new ActionDescriptor());
        var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary());
        var viewContext = new ViewContext(actionContext, view, viewData, TextWriter.Null);

        viewComponentHelper.Contextualize(viewContext);
        var result = viewComponentHelper.Invoke("MyView").ToString();
    }
}

我收到以下异常

   at Microsoft.Framework.DependencyInjection.ServiceProviderExtensions.GetRequiredService(IServiceProvider provider, Type serviceType)
   at Microsoft.AspNet.Mvc.DefaultViewComponentActivator.<>c__DisplayClass6.<CreateActivateInfo>b__7(ViewContext viewContext)
   at Microsoft.AspNet.Mvc.PropertyActivator`1.Activate(Object view, TContext context)
   at Microsoft.AspNet.Mvc.DefaultViewComponentActivator.Activate(Object viewComponent, ViewContext context)
   at Microsoft.AspNet.Mvc.DefaultViewComponentInvoker.CreateComponent(ViewContext context)
   at Microsoft.AspNet.Mvc.DefaultViewComponentInvoker.InvokeSyncCore(MethodInfo method, ViewContext context)
   at Microsoft.AspNet.Mvc.DefaultViewComponentInvoker.Invoke(ViewComponentContext context)
   at Microsoft.AspNet.Mvc.DefaultViewComponentHelper.InvokeCore(TextWriter writer, Type componentType, Object[] arguments)
   at Microsoft.AspNet.Mvc.DefaultViewComponentHelper.Invoke(Type componentType, Object[] args)
   at Microsoft.AspNet.Mvc.DefaultViewComponentHelper.Invoke(String name, Object[] args)

Answer 1

在启动文件的 ConfigureServices 部分中，您需要注册您的服务，即:

   public void ConfigureServices(IServiceCollection services)
   {
                // Add MVC services to the services container.
                //services.AddMvc();

                services.AddTransient...
    }