CHILD Action Methods in ASP.Net MVC 4

Sachin Kalia
Aug 07, 2014
108.8k
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4
Article

Introduction

In this article we will explore Child Action methods accessible at the View level. In general each public method in a controller class is an action method.

There could be multiple scenarios when we want to display some dynamic information (data) on pages. A Child action is helpful in those scenarios.

A ChildAction method is an action method thought its accessible from the View only, if you invoked this action via an URL then it prompts you an error that we will look down the level in this article.

Child Action Method in ASP.NET MVC4

I have a HomeController in the MVC application that contains code as given below:

public class HomeController : Controller
{
public ActionResult Index()
{
ViewBag.TempValue = "Index Action called at HomeController";
return View();
}
[ChildActionOnly]
public ActionResult ChildAction(string param)
{
ViewBag.Message = "Child Action called. " + param;
return View();
}
}

To behave an action as child action it requires decorating with [ChildActionOnly] as shown in the image below:

Child Action Attribute

Initially it is invoking an Index action that in turn returns to Index views and at the View level it calls the ChildAction named “ChildAction”.

This is the code of index.cshtml:

@{
ViewBag.Title = "Index";
}
<h2>
Index
</h2>
<!DOCTYPE html>
<html>
<head>
<title>Error</title>
</head>
<body>
<ul>
<li>
@ViewBag.TempValue
</li>
<li>@ViewBag.OnExceptionError</li>
@*<li>@{Html.RenderAction("ChildAction", new { param = "first" });}</li>@**@
@Html.Action("ChildAction", "Home", new { param = "first" })
</ul>
</body>
</html>

And this is how we declare an action in a view as depicted in the image below:

Declaring Action in View

Now I run the application and it will call an action method via the Index.cshtml page. And the result is as below:

Calling View in Browser

Note: if you try to access the ChildAction method directly than it prompts you with an error as per the image below.

Copy this URL and paste it into a browser: http://localhost:50255/Home/ChildAction/Second

It prompts you with the error:

Accessing ChildAction View in Browser

It may help you sometime in the future.

Thanks

To understand more about MVC please go through the following link:

MVC Articles

Enjoy coding and reading.