71. Explain TempData in MVC?
TempData is again a key, value pair as ViewData. This is derived from “TempDataDictionary” class. TempData is used when the data is to be used in two consecutive requests, this could be between the actions or between the controllers. This requires typecasting in view.
72. What are HTML Helpers in MVC?
HTML Helpers are like controls in traditional web forms. But HTML helpers are more lightweight compared to web controls as it does not hold viewstate and events.
HTML Helpers returns the HTML string which can be directly rendered to HTML page. Custom HTML Helpers also can be created by overriding “HtmlHelper” class.
73. What are AJAX Helpers in MVC?
AJAX Helpers are used to create AJAX enabled elements like as Ajax enabled forms and links which performs the request asynchronously and these are extension methods of AJAXHelper class which exists in namespace – System.Web.Mvc.
74. What are the options can be configured in AJAX helpers?
Below are the options in AJAX helpers –
Url – This is the request URL.
Confirm – This is used to specify the message which is to be displayed in confirm box.
UpdateTargetId – Target element which is populated from the action returning HTML.
75. What is Layout in MVC?
Layout pages are similar to master pages in traditional web forms. This is used to set the common look across multiple pages. In each child page we can find – /p>
Layout = “~/Views/Shared/TestLayout1.cshtml”;
This indicates child page uses TestLayout page as it’s master page.
76. Explain Sections is MVC?
Section are the part of HTML which is to be rendered in layout page. In Layout page we will use the below syntax for rendering the HTML –
And in child pages we are defining these sections as shown below –
If any child page does not have this section defined then error will be thrown so to avoid that we can render the HTML like this –
@RenderSection(“TestSection”, required: false)
77. Can you explain RenderBody and RenderPage in MVC?
RenderBody is like ContentPlaceHolder in web forms. This will exist in layout page and it will render the child pages/views. Layout page will have only one RenderBody() method. RenderPage also exists in Layout page and multiple RenderPage() can be there in Layout page.
78. What is ViewStart Page in MVC?
This page is used to make sure common layout page will be used for multiple views. Code written in this file will be executed first when application is being loaded.
79. Explain the methods used to render the views in MVC?
Below are the methods used to render the views from action –
View() – To return the view from action.
PartialView() – To return the partial view from action.
RedirectToAction() – To Redirect to different action which can be in same controller or in different controller.
Redirect() – Similar to “Response.Redirect()” in webforms, used to redirect to specified URL.
RedirectToRoute() – Redirect to action from the specified URL but URL in the route table has been matched.
80. What are the sub types of ActionResult?
ActionResult is used to represent the action method result. Below are the subtypes of ActionResult –