Dropdown List is one of the standard controls which we are using in a wide range.

This control restricts the user to select only one item.


Sample Code to do Operations with DopDownList


<asp:DropDownList ID="DropDownList1" runat="server">



Code to Bind the Draopdown List with Data Source


DataSet ds = new DataSet();

ds = GetData();


//For binding data in Draopdown you need to specify which column is

//to displayed Draopdown and which column is the value filed.

//Otherwise Draopdown doesn't is in ambigious to show which column


DropDownList1.DataSource = ds;

DropDownList1.DataTextField = "ItemName";

DropDownList1.DataValueField = "ItemID";




//Code to Add Items into Draopdown List


//By default it adds all list iltems from bottom level


string[] Weeks = { "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };


for (int i = 0; i < Weeks.Length; i++)


    ListItem li = new ListItem(Weeks[i], (i + 1).ToString());





//Code to Insert Items into Draopdown List


//if you want to insert a list item into Draopdown

//you need specify the location



    new ListItem("--Select One--", "-1"));



//Code to access the Draopdown list values


foreach (ListItem li in DropDownList1.Items)


    if (Convert.ToInt32(li.Value) > 10)


        Label1.Text += li.Text + "<br/>";





//Code to clear the selection





//Code to remove all items from DropDownList





//Code to make selected perticular item


//DropDownList deosn't supports muliple selection at a time,

//so for better coding Clear the Selection of items.

//Before goint to make seletion an item check weather

//that item is exist ot not.


if (DropDownList1.Items.Contains(DropDownList1.Items.FindByValue("11")))



    DropDownList1.Items.FindByValue("11").Selected = true;