Question

I thought MVC3 can bind JSON data to model by default.

but this code

server:

[HttpPost]
public ActionResult Save(IList<int> IDs)
{
    return null;
}

client:

$.post('@Url.Action("Save", "Users")', {'IDs' : [1, 2, 3]}, function() {});

don’t work. Why ??

Answer 1

Your code sends IDs[]=1&IDs[]=2&IDs[]=3.

You need send IDs=1&IDs=2&IDs=3.

Set traditional:true parameter to use the traditional style of param serialization.

$.ajax({
    url: '@Url.Action("Save", "Users")',
    type: 'post',
    data: {'IDs' : [1, 2, 3]},
    traditional:true,
    success: function() {
        // ...
    }
})