Asp.Net MVC 3 JSON Model Binding not working
You need to set the content type of the request to application/json:
$.ajax({ url: '/image/tag', type: 'POST', contentType: 'application/json; charset=utf-8', data: $.toJSON(tag), success: function (r) { if (r.success == 1) { window.location.href = r.redirect; } }});Ah, and you don't need to have your Tag model properties start with a lowercase letter:
public class Tag{ public int TagId { get; set; } public string TagName { get; set; }}Remark 1: The JavaScriptSerializer class that ASP.NET MVC 3 uses behind the scenes is capable of properly handling this.
Remark 2: In your Tag action you seem to be returning the following JSON: {"success":0} whereas in your success AJAX callback you seem to be using some r.redirect property which doesn't exist.
Remark 3: Avoid naming your controller actions the same way as your view models. Normally action names should represent verbs (like List, Save, Delete, ...) whereas view models represent resources (TagModel, ...).