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DataGrid.HeaderStyle Property

  • Reference

Definition

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

Gets the style properties of the heading section in the DataGrid control.

C# 
[System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)]
public virtual System.Web.UI.WebControls.TableItemStyle HeaderStyle { get; }

Property Value

TableItemStyle

A TableItemStyle object that contains the style properties of the heading section in the DataGrid control. The default value is an empty TableItemStyle object.

Attributes
PersistenceModeAttribute

Examples

The following code example demonstrates how to use the HeaderStyle property to set the background color of the heading section.

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 language="C#" runat="server">
 
    ICollection CreateDataSource() 
    {
       DataTable dt = new DataTable();
       DataRow dr;
 
       dt.Columns.Add(new DataColumn("IntegerValue", typeof(Int32)));
       dt.Columns.Add(new DataColumn("StringValue", typeof(string)));
       dt.Columns.Add(new DataColumn("DateTimeValue", typeof(string)));
       dt.Columns.Add(new DataColumn("BoolValue", typeof(bool)));
 
       for (int i = 0; i < 100; i++) {
          dr = dt.NewRow();
 
          dr[0] = i;
          dr[1] = "Item " + i.ToString();
          dr[2] = DateTime.Now.ToShortDateString();
          dr[3] = (i % 2 != 0) ? true : false;
 
          dt.Rows.Add(dr);
       }
 
       DataView dv = new DataView(dt);
       return dv;
    }
 
    void Page_Load(Object sender, EventArgs e) 
    {
       if (chk1.Checked)
          MyDataGrid.PagerStyle.Mode = PagerMode.NumericPages;
       else 
          MyDataGrid.PagerStyle.Mode = PagerMode.NextPrev;
 
       BindGrid();
    }
 
    void MyDataGrid_Page(Object sender, DataGridPageChangedEventArgs e)
   
    {
       MyDataGrid.CurrentPageIndex = e.NewPageIndex;
       BindGrid();
    }
 
    void BindGrid() 
    {
       MyDataGrid.DataSource = CreateDataSource();
       MyDataGrid.DataBind();
       ShowStats();
    }
 
    void ShowStats() 
    {
       lblEnabled.Text = "AllowPaging is " + MyDataGrid.AllowPaging;
       lblCurrentIndex.Text = "CurrentPageIndex is " + MyDataGrid.CurrentPageIndex;
       lblPageCount.Text = "PageCount is " + MyDataGrid.PageCount;
       lblPageSize.Text = "PageSize is " + MyDataGrid.PageSize;
    }
 
 
 </script>
 
 <head runat="server">
    <title>DataGrid Example</title>
</head>
<body>
 
    <h3>DataGrid Example</h3>
 
    <form id="form1" runat="server">
 
       <asp:DataGrid id="MyDataGrid" runat="server"
            AllowPaging="True"
            PageSize="10"            
            ShowFooter="true"
            OnPageIndexChanged="MyDataGrid_Page"
            BorderColor="black"
            BorderWidth="1"
            GridLines="Both"
            CellPadding="3"
            CellSpacing="0"
            Font-Names="Verdana"
            Font-Size="8pt">

          <PagerStyle Mode="NumericPages"
                      HorizontalAlign="Right">
          </PagerStyle>

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

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

          <AlternatingItemStyle BackColor="#eeeeee">
          </AlternatingItemStyle>

       </asp:DataGrid>
 
       <br />
 
       <asp:Checkbox id="chk1" runat="server"
            Text="Show numeric page navigation buttons"
            Font-Names="Verdana"
            Font-Size="8pt"
            AutoPostBack="true"/>
 
       <br />
 
       <table style="background-color:#eeeeee; padding:6">
          <tr>
             <td style="display:inline">
                
 
                   <asp:Label id="lblEnabled" 
                        runat="server"/><br />
                   <asp:Label id="lblCurrentIndex" 
                        runat="server"/><br />
                   <asp:Label id="lblPageCount" 
                        runat="server"/><br />
                   <asp:Label id="lblPageSize" 
                        runat="server"/><br />
 
                
             </td>
          </tr>
       </table>
 
    </form>
 
 </body>
 </html>
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 DataGrid 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)));
 
         // Populate the table with sample values.
         for (int i = 0; i < 5; i++) 
         {
            dr = dt.NewRow();
 
            dr[0] = i;
            dr[1] = "Item " + i.ToString();
            dr[2] = 1.23 * (i + 1);
 
            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) 
         {
            ItemsGrid.DataSource = CreateDataSource();
            ItemsGrid.DataBind();
         }

      }

      void Button_Click(Object sender, EventArgs e) 
      {

         // Count the number of selected items in the DataGrid control.
         int count = 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.
         foreach (DataGridItem item in ItemsGrid.Items)
         {

            DetermineSelection(item, ref count);        

         }

         // If no items are selected, display the appropriate message.
         if (count == 0)
         {

            Message.Text = "Not items selected";

         }

      }

      void DetermineSelection(DataGridItem item, ref int count)
      {

         // Retrieve the SelectCheckBox CheckBox control from the specified item (row) in the 
         // DataGrid control.
         CheckBox selection = (CheckBox)item.FindControl("SelectCheckBox");

         // If the item is selected, display the appropriate message and increment the count
         // of selected items.
         if (selection != null)
         {

           if (selection.Checked)
           {
              Message.Text += "- " + item.Cells[1].Text + "<br />";
              count++;
           }

         }    

      }

      void Selection_Change(Object sender, EventArgs e)
      {

         // Set the background color for the heading and footer sections of
         // the DataGrid control.
         ItemsGrid.HeaderStyle.BackColor = System.Drawing.Color.FromName(List.SelectedItem.Value);
         ItemsGrid.FooterStyle.BackColor = System.Drawing.Color.FromName(List.SelectedItem.Value);

      }

   </script>
 
<head runat="server">
    <title>DataGrid HeaderStyle and FooterStyle Example</title>
</head>
<body>
 
   <form id="form1" runat="server">
 
      <h3>DataGrid HeaderStyle and FooterStyle Example</h3>

      Select a backcolor for the header and footer sections.

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

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

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

         <Columns>

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

            <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>

Remarks

Use this property to provide a custom style for the heading section of the DataGrid control. Common style attributes that can be adjusted include forecolor, backcolor, font, and content alignment within the cell. Providing a different style enhances the appearance of the DataGrid control.

The HeaderStyle property of the DataGrid control inherits the style settings of the ControlStyle property. For example, if you specify a red font for the ControlStyle property, the HeaderStyle property will also have a red font. This allows you to provide a common appearance for the control by setting a single style property. You can override the inherited style settings by setting the HeaderStyle property. For example, you can specify a blue font for the HeaderStyle property, overriding the red font specified in the ControlStyle property.

To specify a custom style for the heading section, place the <HeaderStyle> tags between the opening and closing tags of the DataGrid control. You can then list the style attributes within the opening <HeaderStyle> tag.

Poznámka

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

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