TemplateColumn.HeaderTemplate Property
Gets or sets the template for displaying the heading section of the TemplateColumn.
[Visual Basic] Public Overridable Property HeaderTemplate As ITemplate [C#] public virtual ITemplate HeaderTemplate {get; set;} [C++] public: __property virtual ITemplate* get_HeaderTemplate(); public: __property virtual void set_HeaderTemplate(ITemplate*); [JScript] public function get HeaderTemplate() : ITemplate; public function set HeaderTemplate(ITemplate);
Property Value
A System.Web.UI.ITemplate implemented object that contains the template for displaying the heading section of the TemplateColumn. The default value is a null reference (Nothing in Visual Basic), which indicates that this property is not set.
Remarks
Use the HeaderTemplate property to control the appearance of the heading section in the TemplateColumn. 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 more complex by embedding other controls in the template.
Example
[Visual Basic, C#] The following example demonstrates how to use the HeaderTemplate property to control the appearance of the heading section in the TemplateColumn.
[Visual Basic] <%@ Page Language="VB" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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> <body> <form 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> [C#] <%@ Page Language="C#" AutoEventWireup="True" %> <%@ Import Namespace="System.Data" %> <html> <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> <body> <form 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>
[C++, JScript] No example is available for C++ or JScript. To view a Visual Basic or C# example, click the Language Filter button
in the upper-left corner of the page.
Requirements
Platforms: Windows 2000, Windows XP Professional, Windows Server 2003 family
See Also
TemplateColumn Class | TemplateColumn Members | System.Web.UI.WebControls Namespace | System.Web.UI.ITemplate | FooterTemplate | ItemTemplate | EditItemTemplate