Here Mudassar Ahmed Khan has explained with an example, how to implement Cascading (Dependent) ComboBox in Windows Forms (WinForms) application using C# and VB.Net.

The three Cascading ComboBox i.e. for Country, State and City will be populated from SQL Server database in Windows Forms (WinForms) application using C# and VB.Net.

Here Mudassar Ahmed Khan has explained a simple tutorial with an example, how to implement ASP.Net AJAX ComboBox Extender control of the ASP.Net Ajax Control Toolkit Library using C# and VB.Net.

The ASP.Net AJAX ComboBox Extender control is used since it allows user to combine the features of DropDownList and AutoComplete TextBox in one control.