OOP Class12

Dymnically Adding Elements

Say we have an empty drop down list.

<asp:DropDownList id="ddlCheese" autopostback="True" runat="server"  />

Since we know that all Lists in the framework contain ListItems we can dymaically add a bunch of cheeses by using a for loop that creates and add ListItems.

ListItem has several constuctors

Visibility	Constructor	Parameters
public	ListItem	( )
public	ListItem	( String text )
public	ListItem	( String text , String value )
public	ListItem	( String text , String value , Boolean enabled )

<csharp>

       //an array of names of cheese
       string [] aryNames = new string[5];
         
       aryNames [0] = "Feta";
       aryNames [1] = "Colby";
       aryNames [2] = "Gruyere";
       aryNames [3] = "Edam";
       aryNames [4] = "Colby";

       foreach (string cheeseName in aryNames)
       {
           ListItem newItem = new ListItem(cheeseName, cheeseName);   //get a new list item 
                                                   //with i for string text and i for value
           ddlCheese.Items.Add(newItem);   
       }</csharp>

CheeseArray.aspx - source

CheeseObject.aspx - source