DataGrid.ItemDataBound Evento
Definizione
Importante
Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.
Viene generato quando un elemento viene associato ai dati del controllo DataGrid.
public:
event System::Web::UI::WebControls::DataGridItemEventHandler ^ ItemDataBound;public event System.Web.UI.WebControls.DataGridItemEventHandler ItemDataBound;member this.ItemDataBound : System.Web.UI.WebControls.DataGridItemEventHandler Public Custom Event ItemDataBound As DataGridItemEventHandler Tipo evento
Esempio
Nell'esempio di codice seguente viene illustrato come specificare e codificare un gestore per l'evento ItemDataBound per visualizzare l'ordine di associazione dei dati degli elementi in DataGrid .
<%@ 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>
Commenti
L'evento ItemDataBound viene generato dopo che un elemento è associato a dati al DataGrid controllo . Questo evento offre l'ultima opportunità di accedere all'elemento di dati prima che venga visualizzato nel client. Dopo la generazione di questo evento, l'elemento di dati viene disattivato e non è più disponibile.
Per altre informazioni su come gestire gli eventi, vedere la gestione e generazione di eventi.
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