Blogs

In this post, we will use in the data binding a custom JsonResult Class for ASP.Net MVC to avoid MaxJsonLength Exceeded Exception. The class is called LargeJsonResult. Here’s its implementation:

using System;
using System.Web.Script.Serialization;
namespace System.Web.Mvc
{
    public class LargeJsonResult : JsonResult
    {
        const string JsonRequest_GetNotAllowed = "This request has been blocked because sensitive information could be disclosed to third party web sites when this is used in a GET request. To allow GET requests, set JsonRequestBehavior to AllowGet.";
        public LargeJsonResult()
        {
            MaxJsonLength = 1024000;
            RecursionLimit = 100;
        }
        public int MaxJsonLength { get; set; }
        public int RecursionLimit { get; set; }
        public override void ExecuteResult( ControllerContext context )
        {
            if( context == null )
            {
                throw new ArgumentNullException( "context" );
            }
            if( JsonRequestBehavior == JsonRequestBehavior.DenyGet &&
                String.Equals( context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase ) )
            {
                throw new InvalidOperationException( JsonRequest_GetNotAllowed );
            }
            HttpResponseBase response = context.HttpContext.Response;
            if( !String.IsNullOrEmpty( ContentType ) )
            {
                response.ContentType = ContentType;
            }
            else
            {
                response.ContentType = "application/json";
            }
            if( ContentEncoding != null )
            {
                response.ContentEncoding = ContentEncoding;
            }
            if( Data != null )
            {
                JavaScriptSerializer serializer = new JavaScriptSerializer() { MaxJsonLength = MaxJsonLength, RecursionLimit = RecursionLimit };
                response.Write( serializer.Serialize( Data ) );
            }
        }
    }
}

In a Controller class called CustomersController, we will implement a method called GetCustomers which returns LargeJsonResult. If you are new to using the jqxGrid with ASP .NET MVC, you can take a look at this help topic: jquery-grid-to-sql-database.htm

public LargeJsonResult GetCustomers()
{
    var dbResult = db.Customers.ToList();
    var customers = from customer in dbResult
                    select new 
                    { 
                        customer.CompanyName, 
                        customer.ContactName, 
                        customer.ContactTitle, 
                        customer.Address, 
                        customer.City 
                    };
    return new LargeJsonResult { Data = customers, JsonRequestBehavior = System.Web.Mvc.JsonRequestBehavior.AllowGet };
} 

The last step is to create and populate the jqxGrid with data.

var source = {
    datatype: "json",
    datafields: [{ name: 'CompanyName' }, { name: 'ContactName' },
    { name: 'ContactTitle' }, { name: 'Address' }, { name: 'City'} ],
    url: 'Customers/GetCustomers'
};
var dataAdapter = new $.jqx.dataAdapter(source);
$("#jqxgrid").jqxGrid({
    source: dataAdapter,
    theme: 'classic',
    columns: [{ text: 'Company Name', datafield: 'CompanyName', width: 250 },
                { text: 'Contact Name', datafield: 'ContactName', width: 150 },
                { text: 'Contact Title', datafield: 'ContactTitle', width: 180 },
                { text: 'Address', datafield: 'Address', width: 200 },
                { text: 'City', datafield: 'City', width: 120}]
});