DataGrid.OnItemDataBound(DataGridItemEventArgs) Metoda
Definice
Důležité
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ItemDataBound Vyvolá událost. To vám umožní zadat vlastní obslužnou rutinu události.
protected:
virtual void OnItemDataBound(System::Web::UI::WebControls::DataGridItemEventArgs ^ e);protected virtual void OnItemDataBound (System.Web.UI.WebControls.DataGridItemEventArgs e);abstract member OnItemDataBound : System.Web.UI.WebControls.DataGridItemEventArgs -> unit
override this.OnItemDataBound : System.Web.UI.WebControls.DataGridItemEventArgs -> unitProtected Overridable Sub OnItemDataBound (e As DataGridItemEventArgs)Parametry
A DataGridItemEventArgs , který obsahuje data událostí.
Příklady
Následující příklad kódu ukazuje, jak určit a kód obslužné rutiny pro ItemDataBound událost, aby se zobrazilo pořadí, ve kterém jsou položky v DataGrid ohraničené daty.
<%@ 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">
DataTable Cart;
DataView CartView;
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("CurrencyValue", typeof(double)));
for (int i = 0; i < 10; 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)
{
if (!IsPostBack)
{
// Need to load this data only once.
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
void Item_Bound(Object sender, DataGridItemEventArgs e)
{
Label1.Text = Label1.Text + " " + e.Item.ItemIndex;
}
</script>
<head runat="server">
<title>DataGrid ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid ItemDataBound Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="true"
OnItemDataBound="Item_Bound"
AutoGenerateColumns="true">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
</asp:DataGrid>
<br />
<asp:Label id="Label1"
Text="Order of items data bound: "
runat="server"/>
<br />
<asp:Label id="Label2"
Text="Note: The -1's refer to the header and footer."
runat="server"/>
</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">
Dim Cart As DataTable
Dim CartView As DataView
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("CurrencyValue", GetType(Double)))
Dim i As Integer
For i = 0 To 9
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 New DataView(dt)
Return dv
End Function 'CreateDataSource
Sub Page_Load(sender As Object, e As EventArgs)
If Not IsPostBack Then
' Need to load this data only once.
ItemsGrid.DataSource = CreateDataSource()
ItemsGrid.DataBind()
End If
End Sub 'Page_Load
Sub Item_Bound(sender As Object, e As DataGridItemEventArgs)
Label1.Text = Label1.Text & " " & e.Item.ItemIndex
End Sub 'Item_Bound
</script>
<head runat="server">
<title>DataGrid ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid ItemDataBound Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="true"
OnItemDataBound="Item_Bound"
AutoGenerateColumns="true">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
</asp:DataGrid>
<br />
<asp:Label id="Label1"
Text="Order of items data bound: "
runat="server"/>
<br />
<asp:Label id="Label2"
Text="Note: The -1's refer to the header and footer."
runat="server"/>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" Debug="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<=10; 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 Item_Bound(Object sender, DataGridItemEventArgs e)
{
// Use the ItemDataBound event to customize the DataGrid control.
// The ItemDataBound event allows you to access the data before
// the item is displayed in the control. In this example, the
// ItemDataBound event is used to format the items in the
// CurrencyColumn in currency format.
if((e.Item.ItemType == ListItemType.Item) ||
(e.Item.ItemType == ListItemType.AlternatingItem))
{
// Retrieve the text of the CurrencyColumn from the DataGridItem
// and convert the value to a Double.
Double Price = Convert.ToDouble(e.Item.Cells[2].Text);
// Format the value as currency and redisplay it in the DataGrid.
e.Item.Cells[2].Text = Price.ToString("c");
}
}
</script>
<head runat="server">
<title>DataGrid ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid ItemDataBound Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="true"
OnItemDataBound="Item_Bound">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
</asp:DataGrid>
</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 10
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 Item_Bound(sender As Object, e As DataGridItemEventArgs)
' Use the ItemDataBound event to customize the DataGrid control.
' The ItemDataBound event allows you to access the data before
' the item is displayed in the control. In this example, the
' ItemDataBound event is used to format the items in the
' CurrencyColumn in currency format.
If e.Item.ItemType = ListItemType.Item Or _
e.Item.ItemType = ListItemType.AlternatingItem Then
' Retrieve the text of the CurrencyColumn from the DataGridItem
' and convert the value to a Double.
Dim Price As Double = Convert.ToDouble(e.Item.Cells(2).Text)
' Format the value as currency and redisplay it in the DataGrid.
e.Item.Cells(2).Text = Price.ToString("c")
End If
End Sub
</script>
<head runat="server">
<title>DataGrid ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid ItemDataBound Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="true"
OnItemDataBound="Item_Bound">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
</asp:DataGrid>
</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<=10; 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)
{
// Manually register the event-handling method for the
// ItemDataBound event of the DataGrid control.
ItemsGrid.ItemDataBound +=
new DataGridItemEventHandler(this.Item_Bound);
// Load sample data only once, when the page is first loaded.
if (!IsPostBack)
{
ItemsGrid.DataSource = CreateDataSource();
ItemsGrid.DataBind();
}
}
void Item_Bound(Object sender, DataGridItemEventArgs e)
{
// Use the ItemDataBound event to customize the DataGrid control.
// The ItemDataBound event allows you to access the data before
// the item is displayed in the control. In this example, the
// ItemDataBound event is used to format the items in the
// CurrencyColumn in currency format.
if((e.Item.ItemType == ListItemType.Item) ||
(e.Item.ItemType == ListItemType.AlternatingItem))
{
// Retrieve the text of the CurrencyColumn from the DataGridItem
// and convert the value to a Double.
Double Price = Convert.ToDouble(e.Item.Cells[2].Text);
// Format the value as currency and redisplay it in the DataGrid.
e.Item.Cells[2].Text = Price.ToString("c");
}
}
</script>
<head runat="server">
<title>DataGrid ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid ItemDataBound Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="true">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
</asp:DataGrid>
</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 10
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)
' Manually register the event-handling method for the
' ItemDataBound event of the DataGrid control.
AddHandler ItemsGrid.ItemDataBound, AddressOf Item_Bound
' 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 Item_Bound(sender As Object, e As DataGridItemEventArgs)
' Use the ItemDataBound event to customize the DataGrid control.
' The ItemDataBound event allows you to access the data before
' the item is displayed in the control. In this example, the
' ItemDataBound event is used to format the items in the
' CurrencyColumn in currency format.
If e.Item.ItemType = ListItemType.Item Or _
e.Item.ItemType = ListItemType.AlternatingItem Then
' Retrieve the text of the CurrencyColumn from the DataGridItem
' and convert the value to a Double.
Dim Price As Double = Convert.ToDouble(e.Item.Cells(2).Text)
' Format the value as currency and redisplay it in the DataGrid.
e.Item.Cells(2).Text = Price.ToString("c")
End If
End Sub
</script>
<head runat="server">
<title>DataGrid ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataGrid ItemDataBound Example</h3>
<asp:DataGrid id="ItemsGrid" runat="server"
BorderColor="black"
BorderWidth="1"
CellPadding="3"
ShowFooter="true">
<HeaderStyle BackColor="#00aaaa">
</HeaderStyle>
<FooterStyle BackColor="#00aaaa">
</FooterStyle>
</asp:DataGrid>
</form>
</body>
</html>
Poznámky
OnItemDataBound Pomocí metody zadejte vlastní obslužnou rutinu ItemDataBound události.
Událost ItemDataBound je vyvolána poté, co je položka vázaná na DataGrid ovládací prvek. Tato událost poskytuje poslední příležitost pro přístup k datové položce předtím, než se zobrazí na klientovi. Po vyvolání této události se datová položka zruší a přestane být k dispozici.
Vyvolání události spustí obslužnou rutinu události prostřednictvím delegáta. Další informace najdete v tématu Zpracování a vyvolávání událostí.
Poznámky pro dědice
Při přepsání OnItemDataBound(DataGridItemEventArgs) v odvozené třídě nezapomeňte volat metodu základní třídy OnItemDataBound(DataGridItemEventArgs) .
Další informace o zpracování událostí najdete v tématu Zpracování a vyvolávání událostí.
Platí pro
Viz také
Spolupracujte s námi na GitHubu
Zdroj tohoto obsahu najdete na GitHubu, kde můžete také vytvářet a kontrolovat problémy a žádosti o přijetí změn. Další informace najdete v našem průvodci pro přispěvatele.
