CODEWITHSUNDEEP
c#asp.netteleriktelerik-mvc
Roman Kagan
Roman Kagan

Reputation: 10626

Why Telerik's DropDownList doesn't have any values when using ajax databinding?

I'm using Asp.Net with Razor syntax and latest Telerik components. Unfortunately when I click on dropdown box I see nothing in it but VS debugger shows me that I executed _AjaxLoaiding method. How can I solve this mystery (i.e. loading data into DropDownList)?

This is part of my Controller:

        public ActionResult _AjaxLoading(string text) {
        var product = new Dictionary<string, string>();
        product.Add("a","b");
        return new JsonResult { Data = new { Text = "Abc", Value = "123", Produtcs = new SelectList(product, "ProductID", "ProductName") } };
    }

This is part of my View:

@{Html.Telerik().DropDownList()
                                              .Name("documentType").Enable(false)
                                              .HtmlAttributes(new { style = "width:250px;" })
                                              .DataBinding(binding => binding.Ajax().Select("_AjaxLoading", "Applicants"))
                                              .Render();
                                        }

Upvotes: 4

Views: 1748

Answers (1)

Rapha&#235;l Althaus
Rapha&#235;l Althaus

Reputation: 60503

Hmm, your doing a strange thing : You pass a Dictionary<string, string> to your select list, and asserts that the valueField is "ProductId", and TextField is "ProductName".

Your dictionary has not such properties... Strongly typing is good.

So you would need a class Product (or whatever)

public class Product {

    public int ProductId {get;set;}
    public string ProductName {get;set;}

}

and use it, even for test purpose

public ActionResult _AjaxLoading(string text) {
        var products= new List<Product> {
        new Product{ProductId = 1, ProductName="b"}
        };
        return new JsonResult { Data = new { Text = "Abc", Value = "123", Products= new SelectList(products, "ProductID", "ProductName") } };
    }

EDIT :

By the way, if you want "Abc" and "123" in SelectList, this is not the right way to do, look at @Gaby's answer in your previous post https://stackoverflow.com/a/10500876/961526

EDIT 2 :

let's try again

so firt, some of my usual extension classes (I limited them, they used to be more generic, but... anyway)

public static class ComboExtensions
    {
        public static IEnumerable<SelectListItem> ToSelectListItem<T>(this IEnumerable<T> enumerable,
                                                                      Func<T, string> text,
                                                                      Func<T, int> value)
        {
            return enumerable.Select(item => new SelectListItem
                                                 {
                                                     Text = text(item).ToString(),
                                                     Value = value(item).ToString(),
                                                 }).AsEnumerable();
        }

        public static IEnumerable<SelectListItem> WithDefaultValue(this IEnumerable<SelectListItem> selectListItems, int defaultValue = 0, string chooseText = "choose")
        {
            IList<SelectListItem> items = selectListItems.ToList();
            items.Insert(0, new SelectListItem {Value = defaultValue.ToString(), Text = chooseText});

then

public ActionResult _AjaxLoading(string text) {
            var products = new List<Product>
                               {
                                   new Product {ProductId = 1, ProductName = "b"}
                               }.ToSelectListItem(m => m.ProductName, m => m.ProductId)
                               .WithDefaultValue(1, "abc");
            return new JsonResult { Data = products } };
}

Upvotes: 4

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