DataGridColumn.HeaderStyle Property

 

Gets the style properties for the header section of the column.

Namespace:   System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

<PersistenceModeAttribute(PersistenceMode.InnerProperty)>
Public Overridable ReadOnly Property HeaderStyle As TableItemStyle

Property Value

Type: System.Web.UI.WebControls.TableItemStyle

A TableItemStyle that contains the style properties for the header section of the column. The default value is an empty TableItemStyle.

Use this property to provide a custom style for the header section of the column. Common style attributes that can be adjusted include foreground color, background color, font, and content alignment within the cell. Providing a different style enhances the appearance of the column in the DataGrid control.

The following code example demonstrates how to use the HeaderStyle property to get the style properties for the header section of the column.


<%@ 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">

      Function CreateDataSource() As ICollection 

         ' Create sample data for the DataGrid control.
         Dim dt As DataTable = New DataTable()
         Dim dr As DataRow

         ' Define the columns of the table.
         dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
         dt.Columns.Add(New DataColumn("StringValue", GetType(string)))
         dt.Columns.Add(New DataColumn("CurrencyValue", GetType(double)))

         ' Populate the table with sample values.
         Dim i As Integer

         For i = 0 to 4 

            dr = dt.NewRow()

            dr(0) = i
            dr(1) = "Item " & i.ToString()
            dr(2) = 1.23 * (i + 1)

            dt.Rows.Add(dr)

         Next i

         Dim dv As DataView = New DataView(dt)
         Return dv

      End Function

      Sub Page_Load(sender As Object, e As EventArgs) 

         ' Load sample data only once, when the page is first loaded.
         If Not IsPostBack Then 

            ItemsGrid.DataSource = CreateDataSource()
            ItemsGrid.DataBind()

         End If

      End Sub

      Sub Button_Click(sender As Object, e As EventArgs) 

         ' Count the number of selected items in the DataGrid control.
         Dim count As Integer = 0

         ' Display the selected times.
         Message.Text = "You Selected: <br />"

         ' Iterate through each item (row) in the DataGrid control and
         ' determine whether it is selected.
         Dim item As DataGridItem

         For Each item In ItemsGrid.Items

            DetermineSelection(item, count)        

         Next

         ' If no items are selected, display the appropriate message.
         If count = 0 Then

            Message.Text = "No items selected"

         End If

      End Sub

      Sub DetermineSelection(item As DataGridItem, ByRef count As Integer)

         ' Retrieve the SelectCheckBox CheckBox control from the 
         ' specified item (row) in the DataGrid control.
         Dim selection As CheckBox = _
             CType(item.FindControl("SelectCheckBox"), CheckBox)

         ' If the item is selected, display the appropriate message and
         ' increment the count of selected items.
         If Not selection Is Nothing Then

           If selection.Checked Then

              Message.Text &= "- " & item.Cells(1).Text & "<br />"
              count = count + 1

           End If

         End If    

      End Sub

      Sub Selection_Change(sender As Object, e As EventArgs)

         ' Set the background color for the header and footer sections
         ' of the first column in the DataGrid control.
         ItemsGrid.Columns(0).HeaderStyle.BackColor = _
             System.Drawing.Color.FromName(List.SelectedItem.Value)
         ItemsGrid.Columns(0).FooterStyle.BackColor = _
             System.Drawing.Color.FromName(List.SelectedItem.Value)

      End Sub

   </script>

<head runat="server">
    <title>DataGridColumn HeaderStyle and FooterStyle Example</title>
</head>
<body>

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

      <h3>DataGridColumn HeaderStyle and FooterStyle Example</h3>

      Select a background color for the header and 
      footer sections of the first column.

      <br /><br />

      <b>Product List</b>

      <asp:DataGrid id="ItemsGrid"
           BorderColor="black"
           BorderWidth="1"
           CellPadding="3"
           ShowFooter="True"
           AutoGenerateColumns="False"
           runat="server">

         <HeaderStyle BackColor="#00aaaa">
         </HeaderStyle>

         <FooterStyle BackColor="#00aaaa">
         </FooterStyle>

         <Columns>

            <asp:BoundColumn DataField="IntegerValue" 
                 HeaderText="Item">

               <HeaderStyle BackColor="White">
               </HeaderStyle>

               <FooterStyle BackColor="White">
               </FooterStyle>

            </asp:BoundColumn>

            <asp:BoundColumn DataField="StringValue" 
                 HeaderText="Description"/>

            <asp:BoundColumn DataField="CurrencyValue" 
                 HeaderText="Price"
                 DataFormatString="{0:c}">

               <ItemStyle HorizontalAlign="Right">
               </ItemStyle>

            </asp:BoundColumn>

            <asp:TemplateColumn HeaderText="Select Item">

               <ItemTemplate>

                  <asp:CheckBox id="SelectCheckBox"
                       Text="Add to Cart"
                       Checked="False"
                       runat="server"/>

               </ItemTemplate>

            </asp:TemplateColumn>

         </Columns> 

      </asp:DataGrid>

      <br /><br />

      <asp:Button id="SubmitButton"
           Text="Submit"
           OnClick = "Button_Click"
           runat="server"/>

      <br /><br />

      <asp:Label id="Message"
           runat="server"/>

      <hr />

      Header and footer BackColor: <br /> 

      <asp:DropDownList id="List"
           AutoPostBack="True"
           OnSelectedIndexChanged="Selection_Change"
           runat="server">

         <asp:ListItem Selected="True" Value="White"> White </asp:ListItem>
         <asp:ListItem Value="Silver"> Silver </asp:ListItem>
         <asp:ListItem Value="DarkGray"> Dark Gray </asp:ListItem>
         <asp:ListItem Value="Khaki"> Khaki </asp:ListItem>
         <asp:ListItem Value="DarkKhaki"> Dark Khaki </asp:ListItem>

      </asp:DropDownList>

   </form>

</body>
</html>

.NET Framework
Available since 1.1
Return to top
Show: