DataGridColumn.HeaderStyle プロパティ

[アーティクル]
06/26/2007

列のヘッダーセクションのスタイルプロパティを取得します。

名前空間: System.Web.UI.WebControls
アセンブリ: System.Web (system.web.dll 内)

構文

'宣言
Public Overridable ReadOnly Property HeaderStyle As TableItemStyle
'使用
Dim instance As DataGridColumn
Dim value As TableItemStyle

value = instance.HeaderStyle

public virtual TableItemStyle HeaderStyle { get; }

public:
virtual property TableItemStyle^ HeaderStyle {
    TableItemStyle^ get ();
}

/** @property */
public TableItemStyle get_HeaderStyle ()

public function get HeaderStyle () : TableItemStyle

適用できません。

プロパティ値

列のヘッダーセクションのスタイルプロパティを格納している TableItemStyle。既定値は空の TableItemStyle です。

解説

このプロパティを使用して、列のヘッダーセクションのカスタムスタイルを指定します。調整できる共通スタイル属性には、前景色、背景色、フォント、セル内の内容の配置などがあります。異なるスタイルを指定すると、DataGrid コントロール内の列の外観がより優れたものになります。

使用例

HeaderStyle プロパティを使用して、列のヘッダーセクションのスタイルプロパティを取得する方法を次のコード例に示します。

<%@ 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>

<%@ 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 = "No 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 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);

      }

   </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>

プラットフォーム

Windows 98,Windows Server 2000 SP4,Windows CE,Windows Millennium Edition,Windows Mobile for Pocket PC,Windows Mobile for Smartphone,Windows Server 2003,Windows XP Media Center Edition,Windows XP Professional x64 Edition,Windows XP SP2,Windows XP Starter Edition

Microsoft .NET Framework 3.0 は Windows Vista,Microsoft Windows XP SP2,および Windows Server 2003 SP1 でサポートされています。

バージョン情報

.NET Framework

サポート対象 : 3.0,2.0,1.1,1.0

次の方法で共有

DataGridColumn.HeaderStyle プロパティ

構文

プロパティ値

解説

使用例

プラットフォーム

バージョン情報

.NET Framework

参照

関連項目

その他のリソース