TemplateColumn.HeaderTemplate Property

Reference

Definition

Namespace:: System.Web.UI.WebControls

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Gets or sets the template for displaying the heading section of the TemplateColumn object.

public:
 virtual property System::Web::UI::ITemplate ^ HeaderTemplate { System::Web::UI::ITemplate ^ get(); void set(System::Web::UI::ITemplate ^ value); };

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

[<System.ComponentModel.Browsable(false)>]
[<System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)>]
[<System.Web.UI.TemplateContainer(typeof(System.Web.UI.WebControls.DataGridItem))>]
member this.HeaderTemplate : System.Web.UI.ITemplate with get, set

Public Overridable Property HeaderTemplate As ITemplate

Property Value

ITemplate

A ITemplate-implemented object that contains the template for displaying the heading section of the TemplateColumn. The default value is null, which indicates that this property is not set.

Attributes: BrowsableAttribute PersistenceModeAttribute TemplateContainerAttribute

Examples

The following code example demonstrates how to use the HeaderTemplate property to control the appearance of the heading section in the TemplateColumn object.


<%@ 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">

      DataTable Store = new DataTable();
      DataView StoreView;  

      void Page_Load(Object sender, EventArgs e) 
      {
         if(Session["StoreData"] == null)
         {
            DataRow dr;
 
            Store = new DataTable();      

            Store.Columns.Add(new DataColumn("Tax", typeof(String)));
            Store.Columns.Add(new DataColumn("Item", typeof(String)));
            Store.Columns.Add(new DataColumn("Price", typeof(String)));

            Session["StoreData"] = Store;
            
            // Create sample data.
            for (int i = 1; i <= 4; i++) 
            {
               dr = Store.NewRow();

               dr[0] = "0.0%";
               dr[1] = "Item " + i.ToString();
               dr[2] = (1.23 * (i + 1)).ToString();
 
               Store.Rows.Add(dr);
            }       

         }
         else
            Store = (DataTable)Session["StoreData"];

         StoreView = new DataView(Store);
         StoreView.Sort="Item";

         if(!IsPostBack)                    
            BindGrid();
                   
      }

      void MyDataGrid_Edit(Object sender, DataGridCommandEventArgs e) 
      {
         MyDataGrid.EditItemIndex = e.Item.ItemIndex;
         BindGrid();
      }

      void MyDataGrid_Cancel(Object sender, DataGridCommandEventArgs e) 
      {
         MyDataGrid.EditItemIndex = -1;
         BindGrid();
      }

      void MyDataGrid_Update(Object sender, DataGridCommandEventArgs e) 
      {
         // Get the text box that contains the price to edit. 
         // For bound columns the edited value is stored in a text box.
         // The text box is the first control in the Controls collection.
         TextBox priceText = (TextBox)e.Item.Cells[3].Controls[0];

         // Get the check box that indicates whether to include tax from the 
         // TemplateColumn. Notice that in this case, the check box control is
         // second control in the Controls collection.
         CheckBox taxCheck = (CheckBox)e.Item.Cells[2].Controls[1];

         String item = e.Item.Cells[1].Text;
         String price = priceText.Text;
       
         DataRow dr;

         // With a database, use an update command.  Since the data source is 
         // an in-memory DataTable, delete the old row and replace it with a new one.

         // Remove old entry.
         StoreView.RowFilter = "Item='" + item + "'";
         if (StoreView.Count > 0)
            StoreView.Delete(0);
         StoreView.RowFilter = "";
 
         // Add new entry.
         dr = Store.NewRow();

         if (taxCheck.Checked)
            dr[0] = "8.6%";
         else 
            dr[0] = "0.0%";
         dr[1] = item;
         dr[2] = price;
         Store.Rows.Add(dr);

         MyDataGrid.EditItemIndex = -1;
         BindGrid();
      }

      void BindGrid() 
      {
         MyDataGrid.DataSource = StoreView;
         MyDataGrid.DataBind();
      }

   </script>

<head runat="server">
    <title>TemplateColumn Example</title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>TemplateColumn Example</h3>

      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           CellPadding="2"        
           OnEditCommand="MyDataGrid_Edit"
           OnCancelCommand="MyDataGrid_Cancel"
           OnUpdateCommand="MyDataGrid_Update"
           ShowFooter="True"
           AutoGenerateColumns="false">

         <Columns>

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update"
                 ItemStyle-Wrap="false"
                 HeaderText="Edit Controls"/>

            <asp:BoundColumn HeaderText="Description" 
                 ReadOnly="true" 
                 DataField="Item"/>

            <asp:TemplateColumn>

               <HeaderTemplate>
                  <b> Tax </b>
               </HeaderTemplate>

               <ItemTemplate>
                  <asp:Label
                       Text='<%# DataBinder.Eval(Container.DataItem, "Tax") %>'
                       runat="server"/>
               </ItemTemplate>

               <EditItemTemplate>

                  <asp:CheckBox
                       Text="Taxable" 
                       runat="server"/>

               </EditItemTemplate>

               <FooterTemplate>
                  <asp:HyperLink id="HyperLink1"
                       Text="Microsoft"
                       NavigateUrl="http://www.microsoft.com"
                       runat="server"/>
               </FooterTemplate>

            </asp:TemplateColumn>

            <asp:BoundColumn HeaderText="Price" 
                 DataField="Price"/>

         </Columns>

      </asp:DataGrid>

   </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 runat="server">

      Private Store As DataTable = New DataTable()
      Private StoreView As DataView  

      Sub Page_Load(sender As Object, e As EventArgs) 
     
         If IsNothing(Session("StoreData")) Then 
         
            Dim dr As DataRow
            Dim i As Integer
 
            Store = New DataTable()      

            Store.Columns.Add(New DataColumn("Tax", GetType(String)))
            Store.Columns.Add(New DataColumn("Item", GetType(String)))
            Store.Columns.Add(New DataColumn("Price", GetType(String)))

            Session("StoreData") = Store
            
            ' Create sample data.
            For i = 1 to 4 
    
               dr = Store.NewRow()

               dr(0) = "0.0%"
               dr(1) = "Item " & i.ToString()
               dr(2) = (1.23 * (i + 1)).ToString()
 
               Store.Rows.Add(dr)

            Next i       

         Else
            Store = Session("StoreData")

         End If

         StoreView = New DataView(Store)
         StoreView.Sort="Item"

         If Not IsPostBack Then                    
            BindGrid()
         End If
                   
      End Sub

      Sub MyDataGrid_Edit(sender As Object, e As DataGridCommandEventArgs) 
      
         MyDataGrid.EditItemIndex = e.Item.ItemIndex
         BindGrid()

      End Sub

      Sub MyDataGrid_Cancel(sender As Object, e As DataGridCommandEventArgs) 
      
         MyDataGrid.EditItemIndex = -1
         BindGrid()

      End Sub

      Sub MyDataGrid_Update(sender As Object, e As DataGridCommandEventArgs) 
      
         ' Get the text box that contains the price to edit. 
         ' For bound columns the edited value is stored in a text box.
         ' The text box is the first control in the Controls collection.
         Dim priceText As TextBox = e.Item.Cells(3).Controls(0)

         ' Get the check box that indicates whether to include tax from the 
         ' TemplateColumn. Notice that in this case, the check box control is
         ' second control in the Controls collection.
         Dim taxCheck As CheckBox = e.Item.Cells(2).Controls(1)

         Dim item As String = e.Item.Cells(1).Text
         Dim price As String = priceText.Text
       
         Dim dr As DataRow

         ' With a database, use an update command.  Since the data source is 
         ' an in-memory DataTable, delete the old row and replace it with a new one.

         ' Remove old entry.
         StoreView.RowFilter = "Item='" & item & "'"
         If StoreView.Count > 0 Then
            StoreView.Delete(0)
         End If
         StoreView.RowFilter = ""
 
         ' Add new entry.
         dr = Store.NewRow()

         If taxCheck.Checked Then
            dr(0) = "8.6%"
         Else 
            dr(0) = "0.0%"
         End If
         dr(1) = item
         dr(2) = price
         Store.Rows.Add(dr)

         MyDataGrid.EditItemIndex = -1
         BindGrid()

      End Sub

      Sub BindGrid() 
      
         MyDataGrid.DataSource = StoreView
         MyDataGrid.DataBind()
      
      End Sub

   </script>

<head runat="server">
    <title>TemplateColumn Example</title>
</head>
<body>

   <form id="form1" runat="server">

      <h3>TemplateColumn Example</h3>

      <asp:DataGrid id="MyDataGrid" runat="server"
           BorderColor="black"
           CellPadding="2"        
           OnEditCommand="MyDataGrid_Edit"
           OnCancelCommand="MyDataGrid_Cancel"
           OnUpdateCommand="MyDataGrid_Update"
           ShowFooter="True"
           AutoGenerateColumns="false">

         <Columns>

            <asp:EditCommandColumn
                 EditText="Edit"
                 CancelText="Cancel"
                 UpdateText="Update"
                 ItemStyle-Wrap="false"
                 HeaderText="Edit Controls"/>

            <asp:BoundColumn HeaderText="Description" 
                 ReadOnly="true" 
                 DataField="Item"/>

            <asp:TemplateColumn>

               <HeaderTemplate>
                  <b> Tax </b>
               </HeaderTemplate>

               <ItemTemplate>
                  <asp:Label
                       Text='<%# DataBinder.Eval(Container.DataItem, "Tax") %>'
                       runat="server"/>
               </ItemTemplate>

               <EditItemTemplate>

                  <asp:CheckBox
                       Text="Taxable" 
                       runat="server"/>

               </EditItemTemplate>

               <FooterTemplate>
                  <asp:HyperLink id="HyperLink1"
                       Text="Microsoft"
                       NavigateUrl="http://www.microsoft.com"
                       runat="server"/>
               </FooterTemplate>

            </asp:TemplateColumn>

            <asp:BoundColumn HeaderText="Price" 
                 DataField="Price"/>

         </Columns>

      </asp:DataGrid>

   </form>

</body>
</html>

Remarks

Use the HeaderTemplate property to control the appearance of the heading section in the TemplateColumn object. The appearance is specified by creating a template that defines how the item is rendered in the column. To specify a template for the item selected for editing, first place opening and closing <HeaderTemplate> tags between the opening and closing tags of the <TemplateColumn> element. You can then list the content that controls the appearance of the item between the opening and closing <HeaderTemplate> tags. The content can be as simple as plain text, or can be made more complex by embedding other controls in the template.

Applies to

Jaa