.net MVC下跨域Ajax请求(JSONP)

<script type="text/javascript">
    function TestJsonp() {
        $.ajax({
            type: "GET",url: "http://localhost/MVC/Books/JsonpTest",dataType: "JSONP",jsonpCallback: "ExecJsonpCallback"
        })
    }

    function ExecJsonpCallback(obj) {
        alert(obj.Name);
    }
</script>

    public class JsonpResult : JsonResult
    {
        public JsonpResult()
        {
            JsonRequestBehavior = JsonRequestBehavior.AllowGet;
        }
        public override void ExecuteResult(ControllerContext context)
        {
            var httpContext = context.HttpContext;
            string callback = context.HttpContext.Request["callback"];
            httpContext.Response.Write(callback + "(");
            base.ExecuteResult(context);
            httpContext.Response.Write(");");
        }
    }
    public class BooksController : Controller
    {
        public ActionResult JsonpTest()
        {
            return new JsonpResult { Data = new { Name = "JSONP" } };
        }
    }