MVC视图中的@Html.xxx(...)ASP.NETMVC视图中的@Html.xxx(...)

public abstract class BuildManagerCompiledView : IView
{
    public void Render(ViewContext viewContext, TextWriter writer)
    {
        if (viewCOntext== null)
        {
            throw new ArgumentNullException("viewContext");
        }
 
        object instance = null;
        //获取被编译的视图页(cshtml文件)的类型                                                                 
        Type type = BuildManager.GetCompiledType(ViewPath);
        if (type != null)
        {
            //通过SingleServiceResolver利用反射和缓存的原理创建视图页的实例，过程类似SingleServiceResolver类对Controller的激活。
            instance = ViewPageActivator.Create(_controllerContext, type);
        }
 
        if (instance == null)
        {
            throw new InvalidOperationException(
                String.Format(
                    CultureInfo.CurrentCulture,
                    MvcResources.CshtmlView_ViewCouldNotBeCreated,
                    ViewPath));
        }
        //执行RenderView方法
        RenderView(viewContext, writer, instance);
    }
}
public class RazorView : BuildManagerCompiledView
{
    protected override void RenderView(ViewContext viewContext, TextWriter writer, object instance)
    {
        if (writer == null)
        {
            throw new ArgumentNullException("writer");
        }
        //将视图页实例转换为WebViewPage对象。
        WebViewPage webViewPage = instance as WebViewPage;
        if (webViewPage == null)
        {
            throw new InvalidOperationException(
                String.Format(
                    CultureInfo.CurrentCulture,
                    MvcResources.CshtmlView_WrongViewBase,
                    ViewPath));
        }
        webViewPage.OverridenLayoutPath = LayoutPath;//母板路径（在第二步中，创建RazorView对象时，由构造函数导入）
        webViewPage.VirtualPath = ViewPath;          //该视图路径
        webViewPage.ViewCOntext= viewContext;       //视图上下文，其中有TempData、controllerContext、ViewData等
        webViewPage.ViewData = viewContext.ViewData;
        
        //WebViewPage对象初始化，执行创建3个xxHelper对象AjaxHelper、HtmlHelper、UrlHelper。
        webViewPage.InitHelpers();
 
        if (VirtualPathFactory != null)
        {
            webViewPage.VirtualPathFactory = VirtualPathFactory;
        }
        if (DisplayModeProvider != null)
        {
            webViewPage.DisplayModeProvider = DisplayModeProvider;
        }
 
        WebPageRenderingBase startPage = null;
        if (RunViewStartPages)
        {
            startPage = StartPageLookup(webViewPage, RazorViewEngine.ViewStartFileName, ViewStartFileExtensions);
        }
        //按层次结构处理视图页的内容。
        webViewPage.ExecutePageHierarchy(new WebPageContext(context: viewContext.HttpContext, page: null, model: null), writer, startPage);
    }
}

public abstract class WebViewPage : WebPageBase, IViewDataContainer, IViewStartPageChild
{
    //省略其他代码...
    public AjaxHelper<object> Ajax
    {
        get;
        set;
    }
    
    public HtmlHelper<object> Html
    {
        get;
        set;
    }
    
    public UrlHelper Url
    {
        get;
        set;
    }
    
    public ViewContext ViewContext
    {
        get;
        set;
    }
    
    public virtual void InitHelpers()
    {
        this.Ajax = new AjaxHelper<object>(this.ViewContext, this);
        this.Html = new HtmlHelper<object>(this.ViewContext, this);
        this.Url = new UrlHelper(this.ViewContext.RequestContext);
    }
}