View generation in ASP. NET MVC

In ASP. net mvc, we divide the front-end presentation into three independent parts for implementation. The Controller is used to control user operations, the View is used to control the presentation content, and the Model is used to represent the processed data. From the Controller to the view, in the Controller, we define multiple actions. The return type of each Action is generally ActionResult. At the end of the Action processing, we return a call to the view. Public ActionResult Index () {return this. view ();} by default, a View with the same name as the Action will be called. For example, a View named Index will be used in the preceding Action. If we pass a string parameter, the string will be considered as the view name. For example, if we want to use the view named IndexView for rendering, we can do the following. Public ActionResult Index () {return this. View ("IndexView");} Will the layout and View MVC go directly to our View? No! After the Action is returned, MVC first checks whether a special file named _ ViewStart. cshtml exists in the Views folder. If yes, It executes the file again. By default, the content of this file is as follows: @ {Layout = "~ /Views/Shared/_ Layout. cshtml ";} That is, it sets our default Layout to use that file. The layout is equivalent to the master page we use in WebForm. If this file is not available, no layout is used by default. What if we don't want to use this layout on the page with this file? It's easy to set Layout = null on the page to overwrite it. @ {Layout = null;} partitions in the Layout are displayed on the Layout page. By default, a special instruction @ RenderBody () exists, will be output here. This is why