DataGrid.HeaderStyle-Eigenschaft
Ruft die Stileigenschaften des Headerzeilenbereichs im DataGrid-Steuerelement ab.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)
Syntax
'Declaration
Public Overridable ReadOnly Property HeaderStyle As TableItemStyle
'Usage
Dim instance As DataGrid
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
Eigenschaftenwert
Ein TableItemStyle-Objekt, das die Stileigenschaften des Headerzeilenbereichs im DataGrid-Steuerelement enthält. Der Standardwert ist ein leeres TableItemStyle-Objekt.
Hinweise
Verwenden Sie diese Eigenschaft, um einen benutzerdefinierten Stil für den Headerzeilenbereich des DataGrid-Steuerelements bereitzustellen. Allgemeine Formatierungsattribute, die angepasst werden können, sind u. a. Vordergrund- und Hintergrundfarbe, Schriftart sowie die Ausrichtung in der Zelle. Die Angabe eines unterschiedlichen Stils führt zu einer verbesserten Darstellung des DataGrid-Steuerelements.
Die HeaderStyle-Eigenschaft des DataGrid-Steuerelements erbt die Stileinstellungen der ControlStyle-Eigenschaft. Wenn Sie z. B. eine rote Schriftart für die ControlStyle-Eigenschaft festlegen, ist für die HeaderStyle-Eigenschaft ebenfalls eine rote Schriftart festgelegt. Somit erreichen Sie ein einheitliche Darstellung des Steuerelements, indem Sie eine einzige Stileigenschaft festlegen. Sie können die geerbten Stileinstellungen überschreiben, indem Sie die HeaderStyle-Eigenschaft festlegen. Sie können z. B. eine blaue Schriftart für die HeaderStyle-Eigenschaft festlegen und damit die in der ControlStyle-Eigenschaft festgelegte rote Schriftart überschreiben.
Zum Angeben eines benutzerdefinierten Stils für den Headerzeilenbereich fügen Sie <HeaderStyle>-Tags zwischen dem öffnenden und dem schließenden Tag des DataGrid-Steuerelements ein. Anschließend können Sie die Stilattribute im öffnenden <HeaderStyle>-Tag auflisten.
Hinweis
Damit diese Eigenschaft angezeigt wird, muss die ShowHeader-Eigenschaft auf true festgelegt werden.
Beispiel
Das folgende Codebeispiel veranschaulicht, wie mit der HeaderStyle-Eigenschaft die Hintergrundfarbe des Headerzeilenbereichs festgelegt wird.
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<script language="VB" runat="server">
Function CreateDataSource() As ICollection
Dim dt As New DataTable()
Dim dr As DataRow
dt.Columns.Add(New DataColumn("IntegerValue", GetType(Int32)))
dt.Columns.Add(New DataColumn("StringValue", GetType(String)))
dt.Columns.Add(New DataColumn("DateTimeValue", GetType(String)))
dt.Columns.Add(New DataColumn("BoolValue", GetType(Boolean)))
Dim i As Integer
For i = 0 To 99
dr = dt.NewRow()
dr(0) = i
dr(1) = "Item " + i.ToString()
dr(2) = DateTime.Now.ToShortDateString()
If i Mod 2 <> 0 Then
dr(3) = True
Else
dr(3) = False
End If
dt.Rows.Add(dr)
Next i
Dim dv As New DataView(dt)
Return dv
End Function 'CreateDataSource
Sub Page_Load(sender As Object, e As EventArgs)
If chk1.Checked Then
MyDataGrid.PagerStyle.Mode = PagerMode.NumericPages
Else
MyDataGrid.PagerStyle.Mode = PagerMode.NextPrev
End If
BindGrid()
End Sub 'Page_Load
Sub MyDataGrid_Page(sender As Object, e As DataGridPageChangedEventArgs)
MyDataGrid.CurrentPageIndex = e.NewPageIndex
BindGrid()
End Sub 'MyDataGrid_Page
Sub BindGrid()
MyDataGrid.DataSource = CreateDataSource()
MyDataGrid.DataBind()
ShowStats()
End Sub 'BindGrid
Sub 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
End Sub 'ShowStats
</script>
<body>
<h3>DataGrid Example</h3>
<form 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-Name="Verdana"
Font-Size="8pt">
<PagerStyle Mode="NumericPages"
HorizontalAlign="Right">
</PagerStyle>
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<FooterStyle BackColor="#aaaadd">
</FooterStyle>
<AlternatingItemStyle BackColor="#eeeeee">
</AlternatingItemStyle>
</asp:DataGrid>
<p>
<asp:Checkbox id="chk1" runat="server"
Text="Show numeric page navigation buttons"
Font-Name="Verdana"
Font-Size="8pt"
AutoPostBack="true"/>
<p>
<table bgcolor="#eeeeee" cellpadding="6">
<tr>
<td nowrap>
<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>
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<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>
<body>
<h3>DataGrid Example</h3>
<form 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-Name="Verdana"
Font-Size="8pt">
<PagerStyle Mode="NumericPages"
HorizontalAlign="Right">
</PagerStyle>
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<FooterStyle BackColor="#aaaadd">
</FooterStyle>
<AlternatingItemStyle BackColor="#eeeeee">
</AlternatingItemStyle>
</asp:DataGrid>
<p>
<asp:Checkbox id="chk1" runat="server"
Text="Show numeric page navigation buttons"
Font-Name="Verdana"
Font-Size="8pt"
AutoPostBack="true"/>
<p>
<table bgcolor="#eeeeee" cellpadding="6">
<tr>
<td nowrap>
<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>
<%@ Page Language="JScript" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<script language="JScript" runat="server">
function CreateDataSource() : ICollection
{
var dt : DataTable = new DataTable();
var dr : DataRow;
dt.Columns.Add(new DataColumn("IntegerValue", Int32));
dt.Columns.Add(new DataColumn("StringValue", System.String));
dt.Columns.Add(new DataColumn("DateTimeValue", System.String));
dt.Columns.Add(new DataColumn("BoolValue", boolean));
for (var i : int = 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);
}
var dv : DataView = new DataView(dt);
return dv;
}
function Page_Load(sender, e : EventArgs)
{
if (chk1.Checked)
MyDataGrid.PagerStyle.Mode = PagerMode.NumericPages;
else
MyDataGrid.PagerStyle.Mode = PagerMode.NextPrev;
BindGrid();
}
function MyDataGrid_Page(sender, e : DataGridPageChangedEventArgs)
{
MyDataGrid.CurrentPageIndex = e.NewPageIndex;
BindGrid();
}
function BindGrid()
{
MyDataGrid.DataSource = CreateDataSource();
MyDataGrid.DataBind();
ShowStats();
}
function 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>
<body>
<h3>DataGrid Example</h3>
<form 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-Name="Verdana"
Font-Size="8pt">
<PagerStyle Mode="NumericPages"
HorizontalAlign="Right">
</PagerStyle>
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<FooterStyle BackColor="#aaaadd">
</FooterStyle>
<AlternatingItemStyle BackColor="#eeeeee">
</AlternatingItemStyle>
</asp:DataGrid>
<p>
<asp:Checkbox id="chk1" runat="server"
Text="Show numeric page navigation buttons"
Font-Name="Verdana"
Font-Size="8pt"
AutoPostBack="true"/>
<p>
<table bgcolor="#eeeeee" cellpadding="6">
<tr>
<td nowrap>
<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>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<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 = "Not 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 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)
End Sub
</script>
<body>
<form 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>
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<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>
<body>
<form 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>
Plattformen
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
DataGrid-Klasse
DataGrid-Member
System.Web.UI.WebControls-Namespace
TableItemStyle
Style
ShowHeader