ASP.NET MVC controller actions that return JSON or partial html

In your action method, return Json(object) to return JSON to your page.

public ActionResult SomeActionMethod() {  return Json(new {foo="bar", baz="Blech"});}

Then just call the action method using Ajax. You could use one of the helper methods from the ViewPage such as

<%= Ajax.ActionLink("SomeActionMethod", new AjaxOptions {OnSuccess="somemethod"}) %>

SomeMethod would be a javascript method that then evaluates the Json object returned.

If you want to return a plain string, you can just use the ContentResult:

public ActionResult SomeActionMethod() {    return Content("hello world!");}

ContentResult by default returns a text/plain as its contentType.
This is overloadable so you can also do:

return Content("<xml>This is poorly formatted xml.</xml>", "text/xml");

I think you should consider the AcceptTypes of the request. I am using it in my current project to return the correct content type as follows.

Your action on the controller can test it as on the request object

if (Request.AcceptTypes.Contains("text/html")) {   return View();}else if (Request.AcceptTypes.Contains("application/json")){   return Json( new { id=1, value="new" } );}else if (Request.AcceptTypes.Contains("application/xml") ||          Request.AcceptTypes.Contains("text/xml")){   //}

You can then implement the aspx of the view to cater for the partial xhtml response case.

Then in jQuery you can fetch it passing the type parameter as json:

$.get(url, null, function(data, textStatus) {        console.log('got %o with status %s', data, textStatus);        }, "json"); // or xml, html, script, json, jsonp or text

Hope this helpsJames

Another nice way to deal with JSON data is using the JQuery getJSON function. You can call the

public ActionResult SomeActionMethod(int id) {     return Json(new {foo="bar", baz="Blech"});}

Method from the jquery getJSON method by simply...

$.getJSON("../SomeActionMethod", { id: someId },    function(data) {        alert(data.foo);        alert(data.baz);    });