ASP.NET MVC ViewResult与PartialViewResult

Question

What is the difference between the controller result named ViewResult and PartialViewResult ? More importantly, when is the PartialViewResult used?

Answer 1

PartialViewResult is used to render a partialview (fx. just a user control). This is pretty nifty for AJAX stuff, ie

<script type="text/javascript">
    $.get(
        "/MyController/MyAction",
        null,
        function (data) { $("#target").html(data) }
     );
</script>

and action

public ActionResult MyAction() 
{
    return PartialView("SomeView");
}

where SomeView is a MVC User Control, eg:

<div>
   <%= DateTime.Now.ToString() %>
</div>

Answer 2

http://msmvps.com/blogs/luisabreu/archive/2008/09/16/the-mvc-platform-action-result-views.aspx

In practice, you'll use the PartialViewResult for outputing a small part of a view. That's why you don't have the master page options when dealing with them. On the other hand, you'll use the ViewResult for getting a “complete” view. As you might expect, the Controller class exposes several methods that will let you reduce the ammount of typing needed for instanting these types of action results.

Generally speaking, ViewResult is for rendering a page with optional master, and PartialViewResult is used for user controls (likely responding to an AJAX request).

Answer 3

none of the existing answers actually answer the question "What is the difference".

The differences are as follows:

1) the locations where the view engine will attempt to find the view:

• for ViewResult, it's in ViewLocationFormats and MasterLocationFormats
• for PartialViewResult, it's in PartialViewLocationFormats

2) ViewResult has the additional property MasterName

that is all.

Answer 4

There are several cases where you would want to break down your view into several small components. One use case that I am working with right now, is I have a multi-lingual site that I would like to reload content using AJAX principles.

Normally what I would do in the case of a non-multi lingual site is to create another ActionResult to return the ViewModel that is changing with the new parameters. I like to use a custom ActionResult that I have called JsonpResult. The problem resides in the fact that I have labels not in my database but in Resource files. So what I would need to do is to somehow hydrate my Resource file data into the ViewModel.

Once the data comes down the pipe, my AJAX callback handles the wiring up of the ViewModel response back to the HTML page using Javascript (I use jQuery).

This definitely works, however it becomes a question of maintainability. I now need to not only maintain my original ASP.NET view, but I also need to maintain a set of scripts that handle AJAXian behavior. If you need to have your site SEO, then you really need to make sure that both the Server Side and Client Side behavior are both working the same.

This is where Partial Views come into play for me. What I do is "pull out" the logical data sections where the bulk of the reload occurs. The nice thing about PartialView is that you can pass your ViewData and Model along to the PartialView. If your PartialView is strongly typed against your ViewModel you can get Intellisense to help with the wiring of the PartialView.

Now all I need to do with my AJAX call is to write the response back to a single DIV rather than handling data points individually. What it does mean is that there would be more content coming down the pipe. However, the trade off is easier to read and maintain code.

Answer 5

The one of the main differences is PartialViewResult doesn't use _ViewStart.cshtml. The code from _ViewStart.cshtml file executes at the start of rendering before any code in the view.