How to Create Child Action Method in ASP.Net MVC

1. A controller is a collection of action methods.
2. Action methods are just like methods and have a public access specifier.
3. Since they are public we can easily call them from a URL request directly from the browser.
4. In our projects, when we want an action method to not be called from a URL request we should make the method a child action method.
5. An action method can be a child or a normal action method, but child actions are action methods invoked from within a view, you cannot invoke a child action method via user request (URL).
6. We can annotate an action method with the [ChildActionOnly] attribute to create a child action. Normally we use child action methods with partial views.
7. Thus [ChildActionOnly] is an attribute when it is preceded over any controller action method. After this, the method could not make a request from the browser, it can only be called from a View.
8. We can call a child action method by using the following two HTML controls.

Now, accessing this Child action method from the browser request will throw the following error.

Now the question is, how and from where to call a child action method. We can call a child action method from the view.

So, we need to create a view for consuming this child action method as in the following:

When defining the @Html.Action() method the first parameter should be your child action name.

As in the preceding code, the child action method is “Display”.

Now for my second parameter, I will pass a name so that it will be consumed and displayed using the child action method.

Now I will explain another example, but now accessing using the @html.RenderAction().

Here is the sum child action method with the same controller.

And this is my view using @html.RenderAction().