ASP.NET MVC Actions

ActionResult

The MVC framework supports several Result classes that can be returned from action methods. Various response types are represented by result classes, including HTML, files, strings, JSON, and javascript. ASP.NET MVC provides some result classes. 

The following table lists them all.

Action Result	Method
ViewResult	View()
EmptyResult	None
RedirectResult	Redirect()
JsonResult	Json()
JavaScriptResult	Javascript()
ContentResult	Content()
FileContentResult FilePathResult FileStreamResult	File()
PartialViewResult	PartialView()

All of the above result classes can be returned by a method that returns ActionResult since this class is the base class for all of them. The action method returns a specific result class, but you may also specify the appropriate result class.

Types of Action Methods

ViewResult 

It is a representation of HTML and markup. The index page will be returned in the following code.

public ViewResult Index() {   
    ViewList.List = "List of values in view";   
    return View();
}

 

EmptyResult 

An empty page with no result will be returned if this action method returns a null result.

public EmptyResult Index() {   
    ViewList.List = "List of values in view";   
    return new EmptyResult();
}             

 

RedirectResult 

Results can be redirected to a specific URL by using Redirect Results. RedirectResult Action Method is useful when redirecting to another action method. It will direct you to the Details Page.    

public RedirectResult Index() {   
    return Redirect("Home/Details");
}

 

JsonResult

A JSON Result file consists of key-value pairs and a simple text file format. In some circumstances, you may wish to return data in JSON format. In that manner, JSONResult is your best choice.     

public JsonResult Index() {
    Example ex = new Example() {
        Name = "Ninja1",
            Id = "00001"
    };
    return Json(ex, JsonRequestBehavior.AllowGet);
}
public class Example {
    public string Name {
        get;
        set;
    }
    public string Id {
        get;
        set;
    }
}

 

JavaScriptResult

This method returns a javascript that can be executed on the client browser. The browser receives javascript content in response. 

JavaScript can be executed on the client at run time using this block below.

 

Add this JavaScriptResult() method in home controller.

[HttpGet]
public JavaScriptResult WarningMessage() {
    var message = "alert('Click ok if you want to continue?');";
    return new JavaScriptResult() {
        Script = message
    };
}

 

In Index.cshtml add the following code.

@ {
    ViewList.Title = "Example";
}
<
script src = "~/Scripts/jquery-1.10.2.js"></script>
<
div class = "data">
    <
h2 style = "color:blue" > ASP.NET MVC Action Methods </h2>
<
/div>
<
script>
    $(document).ready(function () {
    $("button").click(function () {
    $.getScript("/Home/WarningMessage");
});
});
<
/script>
<button> Continue </button>

 

ContentResult

The user-defined content type is returned. A plain text message can be sent to the browser screen using this function below.

using System;
using System.Web.Mvc;
using System.Collections.Generic;

Namespace MvcProject {
    public class HomeController: Controller {
        [HttpGet]
        public ContentResult Index() {
            return Content("What's up developers", "text/plain", System.Text.Encoding.UTF8);
        }
    }
}

 

FileContentResult 

The downloadable file represents the binary content. 

Add the following code in HomeControllers.

[HttpGet]
public FileResult Download() {
    byte[] fileBytes = System.IO.File.ReadAllBytes(@ "C:\Users\filename.txt");
    string filename = "filename.txt";
    return File(fileBytes, System.Net.Mime.MediaTypeNames.Application.Octet, filename);
}

 

Add Action Link in Index.cshtml.

@Html.ActionLink("Download Text File","Download","Home")

This file contains the content of the file.

 

FilePathResult 

It contains a path to a downloadable file.

 

FileStreamResult 

It represents a downloadable file in the form of a file stream.

 

PartialViewResult

Returns HTML from Partial view.

In HomeController.cs add the following code.

[HttpGet]
public PartialViewResult messagepage() {
    return PartialView("message");
}

Now, in Index.cshtml add this code.

@{ 
    Html.RenderAction("messagepage", "Home");
}

FAQs

1. How do ActionResult and ViewResult differ?
   ViewResult is a subtype of ActionResult, which is its base type. You can use ActionResult as the return type for action and any subtypes within this type, e.g., JSON, PartialView, View, RedirectToAction. If you use subtypes, as in this case ViewResult, you are binding your action so it can only return subtypes as results, which is View.
    
2. When to Use ViewResult?
   The ViewResult property can be used if you know that your action method will return a page. Nevertheless, your action method may behave differently, such as rendering a view or performing a redirection. The return type of this method can be the more general ActionResult class.
    
3. Is it possible to have the same action name in MVC?
   It is possible to have two actions with the same name in ASP.NET MVC. You will not be able to use the same name and parameters in two methods on .NET. If you want ASP.NET MVC to know they are one action, you'll need to rename the methods using the ActionName attribute.
    
4. What is the child action method in MVC?
   An MVC Child Action is what it sounds like. Like ASP.NET web forms, ASP.NET MVC Child Actions are like User Controls. Controllers can execute for an area within the rendered area of a view, just like UserControls in Web Forms can perform for an area within the rendered area of a page.

Key Takeaways

This blog shows that responses are generated by ASP.NET MVC Action Methods, which execute requests. ActionResult is the default response type.

There are different types of action results that are returned by actions. They are all subclasses of the ActionResult class.

Apart from this, you can also expand your knowledge by referring to these articles on Features Of ASP Net and ASP Full Form.

Try the guided path from Coding Ninjas if you are a beginner who is interested in learning topics of Web Development and Data Structures and Algorithms.