Edit

DataListItem.ItemIndex Property

  • Reference

Definition

Namespace:
System.Web.UI.WebControls
Assembly:
System.Web.dll

Gets the index of the DataListItem object from the Items collection of the control.

public:
 virtual property int ItemIndex { int get(); };
public virtual int ItemIndex { get; }
member this.ItemIndex : int
Public Overridable ReadOnly Property ItemIndex As Integer

Property Value

Int32

The index of the DataListItem object from the Items collection.

Examples

The following example demonstrates how to use the ItemIndex property to display the index number of the DataListItem object from the Items collection of the control.

Note

The following code sample uses the single-file code model and may not work correctly if copied directly into a code-behind file. This code sample must be copied into an empty text file that has an .aspx extension. For more information on the Web Forms code model, see ASP.NET Web Forms Page Code Model.

<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script language = "C#" runat="server">
 
      ICollection CreateDataSource() 
      {
         DataTable dt = new DataTable();
         DataRow dr;
 
         dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
  
         for (int i = 0; i < 10; i++) 
         {
            dr = dt.NewRow();
            dr[0] = "Item " + i.ToString();
            dt.Rows.Add(dr);
         }
 
         DataView dv = new DataView(dt);
         return dv;
      }
 
      void Page_Load(Object sender, EventArgs e) 
      {
         if (!IsPostBack) 
         {
            DataList1.DataSource = CreateDataSource();
            DataList1.DataBind();
         }
      }
 
      void Button_Click(Object sender, EventArgs e)
      {

         Label1.Text = "The ItemIndex of each item in the DataList are: <br />"; 
 
         foreach (DataListItem item in DataList1.Items)
         { 
            Label1.Text += "<br />" + item.ItemIndex.ToString() + " - " +
                           ((DataBoundLiteralControl)item.Controls[1]).Text;
         }

      }
  
 
   </script>
 
<head runat="server">
    <title>DataListItem ItemIndex Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataListItem ItemIndex Example</h3>
 
      <asp:DataList id="DataList1" runat="server"
           BorderColor="black"
           CellPadding="3"
           Font-Names="Verdana"
           Font-Size="8pt">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
               
         <ItemTemplate>

            <%# DataBinder.Eval(Container.DataItem, "StringValue") %>

         </ItemTemplate>
 
      </asp:DataList>

        <br /><br />

      <asp:Button id="Button1"
           Text="Display ItemIndex for Items in the DataList"
           OnClick="Button_Click"
           runat="server"/>
 
      <br /><br />

      <asp:Label id="Label1"
           runat="server"/>
 
   </form>
 
</body>
</html>

<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
   <script language = "VB" runat="server">
 
    Function CreateDataSource() As ICollection
        Dim dt As New DataTable()
        Dim dr As DataRow
        
        dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
        
        Dim i As Integer
        For i = 0 To 9
            dr = dt.NewRow()
            dr(0) = "Item " & i.ToString()
            dt.Rows.Add(dr)
        Next i
        
        Dim dv As New DataView(dt)
        Return dv
    End Function 'CreateDataSource


    Sub Page_Load(sender As Object, e As EventArgs)
        If Not IsPostBack Then
            DataList1.DataSource = CreateDataSource()
            DataList1.DataBind()
        End If
    End Sub 'Page_Load


    Sub Button_Click(sender As Object, e As EventArgs)
        
        Label1.Text = "The ItemIndex of each item in the DataList are: <br />"
        
        Dim item As DataListItem
        For Each item In  DataList1.Items
            Label1.Text &= "<br />" & item.ItemIndex.ToString() & " - " & CType(item.Controls(1), DataBoundLiteralControl).Text
        Next item
    End Sub 'Button_Click
  
   </script>
 
<head runat="server">
    <title>DataListItem ItemIndex Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataListItem ItemIndex Example</h3>
 
      <asp:DataList id="DataList1" runat="server"
           BorderColor="black"
           CellPadding="3"
           Font-Names="Verdana"
           Font-Size="8pt">

         <HeaderStyle BackColor="#aaaadd">
         </HeaderStyle>

         <AlternatingItemStyle BackColor="Gainsboro">
         </AlternatingItemStyle>

         <HeaderTemplate>

            Items

         </HeaderTemplate>
               
         <ItemTemplate>

            <%# DataBinder.Eval(Container.DataItem, "StringValue") %>

         </ItemTemplate>
 
      </asp:DataList>

        <br /><br />

      <asp:Button id="Button1"
           Text="Display ItemIndex for Items in the DataList"
           OnClick="Button_Click"
           runat="server"/>
 
      <br /><br />

      <asp:Label id="Label1"
           runat="server"/>
 
   </form>
 
</body>
</html>

Remarks

Use the ItemIndex property to determine the index number of the DataListItem object from the Items collection.

Note

This property only applies to data items in the DataList control. The ItemType property of the DataListItem object must be set to ListItemType.Item, ListItemType.AlternatingItem, ListItemType.SelectedItem, or ListItemType.EditItem.

Applies to

See also