List Controls-Basic Web Controls

        ASP.Net provides the controls: drop-down list, list box, radio button list, check box list and Bulleted list. These control let a user choose from one or more items from the list.

     List boxes and drop-down list contain one or more list items. These lists could be loaded either by code or by the List Item Collection Editor.

Basic syntax for list box control:

    <asp:Listbox Id="Listbox1"  runat="server"  autopostback="true"  OnSelectedIndexchanged="Listbox1_SelectedIndexChanged" </asp:listbox>

Basic syntax for a drop-down list control:

   <asp:DropDownList Id="Dropdownlist1: runat="server" autopostback="true" OnSelectedIndexchanged="Listbox1_SelectedIndexChanged" </asp:dropdownlsit>

Common Properties of List box and Drop-down Lists:

     Items: The Collection of List item objects that represents the items in the control.this property returns an object of type list item collection 

     Rows: Specifies the number of items items displayed in the box.if actual list contains more than displayed then a scroll bar is added

     Selected Index: The Index of the currently selected item.If more than one item is selected,then the index of the first selected item.if the no item is selected ,the value of this property is -1

      Selected Value: The value of the currently selected item. If more than one item is selected, then the values of the first selected item. if no item is selected, the value of this property is an empty string

      Selected Mode: Indicates whether a list box allows single selections or multiple selections.

Common Properties of each list item objects:

Property	Description
Text	The text displayed for the item
Selected	Indicates whether the item is selected.
Value	A string value associated with the item.

Note:

•        To work with the items in a drop-down list or list box, you use the Items property of the control. This property returns a ListItemCollection object which contains all the items of the list.
•        The SelectedIndexChanged event is raised when the user selects a different item from a drop-down list or list box.