DataGrid.HeaderStyle Eigenschap
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Hiermee haalt u de stijleigenschappen van de kopsectie in het DataGrid besturingselement op.
public:
virtual property System::Web::UI::WebControls::TableItemStyle ^ HeaderStyle { System::Web::UI::WebControls::TableItemStyle ^ get(); };[System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)]
public virtual System.Web.UI.WebControls.TableItemStyle HeaderStyle { get; }[<System.Web.UI.PersistenceMode(System.Web.UI.PersistenceMode.InnerProperty)>]
member this.HeaderStyle : System.Web.UI.WebControls.TableItemStylePublic Overridable ReadOnly Property HeaderStyle As TableItemStyleWaarde van eigenschap
Een TableItemStyle object met de stijleigenschappen van de kopsectie in het DataGrid besturingselement. De standaardwaarde is een leeg TableItemStyle object.
- Kenmerken
Voorbeelden
In het volgende codevoorbeeld ziet u hoe u de HeaderStyle eigenschap gebruikt om de achtergrondkleur van de kopsectie in te stellen.
<%@ 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>
<%@ 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 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>
<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>
<%@ 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>
<%@ 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 = "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>
<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>
Opmerkingen
Gebruik deze eigenschap om een aangepaste stijl op te geven voor de kopsectie van het DataGrid besturingselement. Algemene stijlkenmerken die kunnen worden aangepast, zijn onder andere voorkleur, backcolor, lettertype en inhoudsuitlijning in de cel. Het bieden van een andere stijl verbetert het uiterlijk van het DataGrid besturingselement.
De HeaderStyle eigenschap van het DataGrid besturingselement neemt de stijlinstellingen van de ControlStyle eigenschap over. Als u bijvoorbeeld een rood lettertype voor de ControlStyle eigenschap opgeeft, heeft de HeaderStyle eigenschap ook een rood lettertype. Hiermee kunt u een gemeenschappelijk uiterlijk voor het besturingselement bieden door één stijleigenschap in te stellen. U kunt de overgenomen stijlinstellingen overschrijven door de eigenschap in te HeaderStyle stellen. U kunt bijvoorbeeld een blauw lettertype voor de HeaderStyle eigenschap opgeven, waarbij het rode lettertype wordt overschreven dat is opgegeven in de ControlStyle eigenschap.
Als u een aangepaste stijl voor de kopsectie wilt opgeven, plaatst u de <HeaderStyle> tags tussen de openings- en eindtags van het DataGrid besturingselement. Vervolgens kunt u de stijlkenmerken in de openingstag <HeaderStyle> weergeven.
Note
De ShowHeader eigenschap moet zodanig worden ingesteld true dat deze eigenschap zichtbaar is.
