Try passing the value like this:
data: JSON.stringify(sortOrder.split(',')),
So that your request payload looks like a string array:
["foo", "bar"]
If you want to pass the value like that:
data: JSON.stringify({ "sortOrder": sortOrder.split(',') }),
then make sure that you have declared a view model:
public class MyViewModel
{
public string[] SortOrder { get; set; }
}
that your controller action will take as parameter:
[Route("updateimagesorder")]
public HttpResponseMessage PutImagesSortOrder(MyViewModel model)
{
// do stuff with parameters
}