jQuery to Dynamically Change or Set Placeholder Text in Asp.Net TextBox on DropDownlist Selected Item Change http://www.webcodeexpert.com/2016/01/jquery-to-dynamically-change-or-set.html In this article I have explained How to dynamically change or set placeholder text in Asp.Net TextBox or Multiline Textbox using jQuery on DropDownList selected item change.
Create XML file and Bind XML data to DropDownList using DataSet in asp.net http://www.webcodeexpert.com/2013/05/create-xml-file-and-bind-xml-data-to.html
Fill CheckBoxList based on DropDownList selection in asp.net(C#, VB) http://www.webcodeexpert.com/2013/04/fill-checkboxlist-based-on-dropdownlist.html
ENTITY FRAMEWORK 6 USING MVC 5: How To Create a Dynamic DropdownList in ASP.NET MV...
jQuery to Enable,Disable,Show and Hide Asp.net DropDownList,TextBox and Button controls based on DropDownList selected value http://www.webcodeexpert.com/2014/08/jquery-to-enabledisableshow-and-hide.html
jQuery to Show/Hide the controls placed inside Div based on Asp.net DropDownList selected value http://www.webcodeexpert.com/2014/07/jquery-to-showhide-div-content-based-on.html
jQuery to clear Asp.Net textbox based on dropdownlist selected item change http://www.webcodeexpert.com/2015/07/jquery-to-clear-aspnet-textbox-based-on.html
Net : Fill dropdownlist or combobox manually C# Examples and VB.Net Examples There is a need in website that you want to add items manually in dropdownlist or combobox. You can achieve this using "Items.Add" methods of dropdownlist.