MVC Developer

ASP.NET Scaffolding is a code generation framework for ASP.NET Web applications. Visual Studio 2013 includes pre-installed code generators for MVC and Web API projects. You add scaffolding to your project when you want to quickly add code that interacts with data models. Using scaffolding can reduce the amount of time to develop standard data operations in your project.

Scaffolding consists of page templates, entity page templates, field page templates, and filter templates. These templates are called Scaffold templates and allow you to quickly build a functional data-driven Website.

Scaffolding Templates:

☛ Create: It creates a View that helps in creating a new record for the Model. It automatically generates a label and input field for each property in the Model.

☛ Delete: It creates a list of records from the model collection along with the delete link with delete record.

☛ Details: It generates a view that displays the label and an input field of the each property of the Model in the MVC framework.

☛ Edit: It creates a View with a form that helps in editing the current Model. It also generates a form with label and field for each property of the model.

☛ List: It generally creates a View with the help of a HTML table that lists the Models from the Model Collection. It also generates a HTML table column for each property of the Model.

RenderSection() is a method of the WebPageBase class. Scott wrote at one point, The first parameter to the "RenderSection()" helper method specifies the name of the section we want to render at that location in the layout template. The second parameter is optional, and allows us to define whether the section we are rendering is required or not. If a section is "required", then Razor will throw an error at runtime if that section is not implemented within a view template that is based on the layout file (that can make it easier to track down content errors). It returns the HTML content to render.

<div id="body">

@RenderSection("featured", required: false)

<section class="content-wrapper main-content clear-fix">

@RenderBody()

</section>

</div>

In the controller you can override the “OnException” event and set the “Result” to the view name which you want to invoke when error occurs. In the below code you can see we have set the “Result” to a view named as “Error”.

We have also set the exception so that it can be displayed inside the view.

public class HomeController : Controller

{

protected override void OnException(ExceptionContext filterContext)

{

Exception ex = filterContext.Exception;

filterContext.ExceptionHandled = true;

var model = new HandleErrorInfo(filterContext.Exception, "Controller","Action");

filterContext.Result = new ViewResult()

{

ViewName = "Error",

ViewData = new ViewDataDictionary(model)

};

}

}

To display the above error in view we can use the below code

@Model.Exception;

ActionResult is an abstract class while ViewResult derives from the ActionResult class.

ActionResult has several derived classes like ViewResult, JsonResult, FileStreamResult, and so on.

ActionResult can be used to exploit polymorphism and dynamism. So if you are returning different types of views dynamically, ActionResult is the best thing. For example in the below code snippet, you can see we have a simple action called DynamicView. Depending on the flag (IsHtmlView) it will either return a ViewResult or JsonResult.

☰ public ActionResult DynamicView()

☰ {

☰ if (IsHtmlView)

☰ return View(); // returns simple ViewResult

☰ else

☰ return Json(); // returns JsonResult view

☰ }

There are total nine return types we can use to return results from controller to view.

☛ ViewResult (View): This return type is used to return a webpage from an action method.

☛ PartialviewResult (Partialview): This return type is used to send a part of a view which will be rendered in another view.

☛ RedirectResult (Redirect): This return type is used to redirect to any other controller and action method depending on the URL.

☛ RedirectToRouteResult (RedirectToAction, RedirectToRoute): This return type is used when we want to redirect to any other action method.

☛ ContentResult (Content): This return type is used to return HTTP content type like text/plain as the result of the action.

☛ jsonResult (json): This return type is used when we want to return a JSON message.

☛ javascriptResult (javascript): This return type is used to return JavaScript code that will run in browser.

☛ FileResult (File): This return type is used to send binary output in response.

☛ EmptyResult: This return type is used to return nothing (void) in the result.

The main purpose of using Output Caching is to dramatically improve the performance of an ASP.NET MVC Application. It enables us to cache the content returned by any controller method so that the same content does not need to be generated each time the same controller method is invoked. Output Caching has huge advantages, such as it reduces server round trips, reduces database server round trips, reduces network traffic etc.

OutputCache label has a "Location" attribute and it is fully controllable. Its default value is "Any", however there are the following locations available; as of now, we can use any one.

☛ Any

☛ Client

☛ Downstream

☛ Server

☛ None

☛ ServerAndClient