Ajax Binding

In this article you will learn how to bind a DropDownList in ASP.NET Core from a database.

You can configure the Telerik UI DropDownList for Ajax binding to the Northwind Products table which uses Linq to SQL.

The ToDataSourceResult() extension method modifies the structure of the result and the widget is not able to bind to it. In this case, return a simple array of data as json.

1. Create an action method which renders the view.

   public ActionResult Index()
   {
       return View();
   }
   

2. Create a new action method and pass the Products table as JSON result.

   public JsonResult GetProducts()
   {
       NorthwindDataContext northwind = new NorthwindDataContext();
   
       return Json(northwind.Products, JsonRequestBehavior.AllowGet);
   }
   

3. Add an Ajax-bound DropDownList.

    @(Html.Kendo().DropDownList()
        .Name("productDropDownList") // The name of the DropDownList is mandatory. It specifies the "id" attribute of the widget.
        .DataTextField("ProductName") // Specify which property of the Product to be used by the DropDownList as a text.
        .DataValueField("ProductID") // Specify which property of the Product to be used by the DropDownList as a value.
        .DataSource(source =>
        {
                source.Read(read =>
                {
                    read.Action("GetProducts", "Home"); // Set the Action and Controller names.
                })
                .ServerFiltering(true); // If true, the DataSource will not filter the data on the client.
        })
        .SelectedIndex(0) // Select the first item.
     )

By following this example, you will be able to populate the ASP.NET Core DropDownList from a database, and the component will visualize the data.

See Also

• Server-Side API