asp.net with C# to display a Country,State,City

Accepted answer

I made some change in code , please go through the attachment doc , you dropdown list auto post back is false making it true, it working fine

Follow below links that may help you:

http://www.aspsnippets.com/Articles/Creating-Cascading-DropDownLists-in-ASP.Net.aspx

https://www.codeproject.com/Questions/433022/Cascading-Country-City-drop-down-list-in-asp-net

https://aspdotnetcodehelp.wordpress.com/2015/04/15/how-to-create-cascading-dropdown-list-in-asp-net/

Make sure You set the AutoPostBack="True" For every control