If users need to deal with large data sets on a certain web page, you need to use a dropdown list virtual scrolling tool that can be used load and display any wanted contents and data sets. Here, we recommend our well developed KT.UI for ASP.NET PerDropDownList Virtual Scrolling functionality.

This manual page talks about how to set DropDownList virtual scrolling feature from following two aspects:

• One is the interpretations of PerDropDownList virtual scrolling developing concept
• The other part is the overall sample ASP.NET codes for setting and defining DropDownList virtual scrolling feature

Kettic UI for ASP.NET AJAX web page DropDownList virtual scrolling functionality enables users to load and display any data set with high speed and great accuracy. Users can set non-limiting data sets within the virtual scrolling application. There are ten data sets displayed in the drop down list by default, and the rest of data sets won’t be load within PerDropDownList virtual scrolling project but have stored running position. Users just need to scroll to find any data set that can be loaded and displayed promptly. What's more, our DropDownList virtual scrolling functionality enables access to items in a non-sequential manner, which means that, if you want to scroll to the bottom of the DropDownList, you don't need to load all the items in between.

In order to enable PerDropDownList Virtual scrolling for browsing large record sets, users need to be sure that the PerDropDownHeight property must be set to utilize the virtual scrolling and also set the EnableVirtualScrolling property to True.

If you have been familiar with above DropDownList virtual scrolling function, you are able to create a particular DropDownList virtual scrolling control. We offer following comprehensive ASP.NET demo codes to help users create and set up your own specified DropDownList virtual scrolling component by using KT.UI for ASP.NET AJAX.

<kettic:PerDropDownList runat="server" ID="PerDropDownList1" DataSourceID="SqlDataSource1" Width="300px" DefaultMessage="Select..."
                DropDownWidth="300px" DropDownHeight="200px" EnableVirtualScrolling="true" DataValueField="CustomerID" DataTextField="ContactName">
</kettic:PerDropDownList>
<asp:SqlDataSource runat="server" ID="SqlDataSource1" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
        ProviderName="System.Data.SqlClient" SelectCommand="SELECT [CustomerID], [ContactName] FROM [Customers] ORDER By ContactName">
</asp:SqlDataSource>