Cascading Dropdownlist in Asp.Net
There are various ways to get the cascading dropdown in the ASP.net. But the following is highly performance oriented approach. For fetching data the data is transferred from web server to client using web service. So the data transfer between server and client is very minimal. Thus you can experience the cascading very fast for a small to medium size of data.
This article needs Ajax Control kit. It needs to be downloaded separately.
Once downloaded, create a new website and select the Default.Aspx and then switch to design mode in the Web Form
Cascading DropDownlist In Web Form
While in design mode, open the tool box and right click and choose items. In the “Choose Toolbox Item” choose the downloaded AjaxControlToolKit.dll.
Now you will see a list Ajax controls in the tool Box.
Drag the Cascading Dropdown to the Web form.
Right click the website and add a web service named Northwind ...