DataList.HeaderTemplate Property

Definition

Gets or sets the template for the heading section of the DataList control.

C#
[System.ComponentModel.Browsable(false)]
[System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)]
[System.Web.UI.TemplateContainer(typeof(System.Web.UI.WebControls.DataListItem))]
public virtual System.Web.UI.ITemplate HeaderTemplate { get; set; }

Property Value

A ITemplate that contains the template for the heading section of the DataList control. The default value is null.

Attributes

Examples

The following code example demonstrates how to use the HeaderTemplate property to control the contents of the heading section of the DataList control.

Poznámka

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.

ASP.NET (C#)

<%@ 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 runat="server">
 
      ICollection CreateDataSource() 
      {
      
         // Create sample data for the DataList control.
         DataTable dt = new DataTable();
         DataRow dr;
 
         // Define the columns of the table.
         dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
         dt.Columns.Add(new DataColumn("StringValue", typeof(String)));
         dt.Columns.Add(new DataColumn("CurrencyValue", typeof(double)));
         dt.Columns.Add(new DataColumn("ImageValue", typeof(String)));
 
         // Populate the table with sample values.
         for (int i = 0; i < 9; i++) 
         {
            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = "Description for item " + i.ToString();
            dr[2] = 1.23 * (i + 1);
            dr[3] = "Image" + i.ToString() + ".jpg";
 
            dt.Rows.Add(dr);
         }
 
         DataView dv = new DataView(dt);
         return dv;
      }
 
 
      void Page_Load(Object sender, EventArgs e) 
      {

         // Load sample data only once, when the page is first loaded.
         if (!IsPostBack) 
         {
            ItemsList.DataSource = CreateDataSource();
            ItemsList.DataBind();
         }

      }
 
      void Button_Click(Object sender, EventArgs e) 
      {
 
         // Set the repeat direction based on the selected value of the
         // DirectionList DropDownList control.
         ItemsList.RepeatDirection = 
             (RepeatDirection)DirectionList.SelectedIndex;

         // Set the repeat layout based on the selected value of the
         // LayoutList DropDownList control.
         ItemsList.RepeatLayout = (RepeatLayout)LayoutList.SelectedIndex;

         // Set the number of columns to display based on the selected
         // value of the ColumnsList DropDownList control.
         ItemsList.RepeatColumns = ColumnsList.SelectedIndex;

         // Show or hide the gridlines based on the value of the
         // ShowBorderCheckBox property. Note that gridlines are displayed
         // only if the RepeatLayout property is set to Table.
         if ((ShowBorderCheckBox.Checked) 
             && (ItemsList.RepeatLayout == RepeatLayout.Table)) 
         {
            ItemsList.BorderWidth = Unit.Pixel(1);
            ItemsList.GridLines = GridLines.Both;
         }    
         else  
         {
            ItemsList.BorderWidth = Unit.Pixel(0);
            ItemsList.GridLines = GridLines.None;
         }
    
      }    
 
   </script>
 
<head runat="server">
    <title>DataList Example</title>
</head>
<body>
 
   <form id="form1" runat="server">

      <h3>DataList Example</h3>
 
      <asp:DataList id="ItemsList"
           BorderColor="black"
           CellPadding="5"
           CellSpacing="5"
           RepeatDirection="Vertical"
           RepeatLayout="Table"
           RepeatColumns="0"
           BorderWidth="0"
           runat="server">

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

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

         <HeaderTemplate>

            List of items

         </HeaderTemplate>
               
         <ItemTemplate>

            Description: <br />
            <%# DataBinder.Eval(Container.DataItem, "StringValue") %>

            <br />

            Price: <%# DataBinder.Eval(Container.DataItem, "CurrencyValue", "{0:c}") %>

            <br />

            <asp:Image id="ProductImage"
                 AlternatingText='<%# DataBinder.Eval(Container.DataItem, "StringValue") %>'
                 ImageUrl='<%# DataBinder.Eval(Container.DataItem, "ImageValue") %>'
                 runat="server"/>

         </ItemTemplate>
 
      </asp:DataList>
 
      <hr />

      <table cellpadding="5">

         <tr>

            <th>

               Repeat direction:

            </th>

            <th>

               Repeat layout:

            </th>

            <th>

               Repeat columns:

            </th>

            <th>

               <asp:CheckBox id="ShowBorderCheckBox"
                    Text="Show border"
                    Checked="False" 
                    runat="server" />

            </th>

         </tr>

         <tr>

            <td>

               <asp:DropDownList id="DirectionList" 
                    runat="server">

                  <asp:ListItem>Horizontal</asp:ListItem>
                  <asp:ListItem Selected="True">Vertical</asp:ListItem>

               </asp:DropDownList>

            </td>

            <td>

               <asp:DropDownList id="LayoutList" 
                    runat="server">

                  <asp:ListItem Selected="True">Table</asp:ListItem>
                  <asp:ListItem>Flow</asp:ListItem>

               </asp:DropDownList>

            </td>

            <td>

               <asp:DropDownList id="ColumnsList" 
                    runat="server">

                  <asp:ListItem Selected="True">0</asp:ListItem>
                  <asp:ListItem>1</asp:ListItem>
                  <asp:ListItem>2</asp:ListItem>
                  <asp:ListItem>3</asp:ListItem>
                  <asp:ListItem>4</asp:ListItem>
                  <asp:ListItem>5</asp:ListItem>

               </asp:DropDownList>

            </td>

            <td>

                

            </td>


         </tr>

      </table>     
         
      <asp:LinkButton id="RefreshButton" 
           Text="Refresh DataList" 
           OnClick="Button_Click" 
           runat="server"/>
 
   </form>
 
</body>
</html>

Remarks

Use the HeaderTemplate property to control the contents of the heading section. The appearance of the header section is controlled by the HeaderStyle property.

Poznámka

The ShowHeader property must be set to true for this property to be visible.

To specify a template for the heading section, place the <HeaderTemplate> tags between the opening and closing tags of the DataList control. You can then list the contents of the template between the opening and closing <HeaderTemplate> tags.

Výstraha

This control can be used to display user input, which might include malicious client script. Check any information that is sent from a client for executable script, SQL statements, or other code before displaying it in your application. You can use validation controls to verify user input before displaying the input text in a control. ASP.NET provides an input request validation feature to block script and HTML in user input. For more information, see Securing Standard Controls, How to: Protect Against Script Exploits in a Web Application by Applying HTML Encoding to Strings, and Validating User Input in ASP.NET Web Pages.

Applies to

Produkt Verzie
.NET Framework 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

See also