DataListItemEventHandler Temsilci
Tanım
Önemli
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Denetimin ve ItemDataBound olaylarını ItemCreatedDataList işleyecek yöntemi temsil eder.
public delegate void DataListItemEventHandler(System::Object ^ sender, DataListItemEventArgs ^ e);public delegate void DataListItemEventHandler(object sender, DataListItemEventArgs e);type DataListItemEventHandler = delegate of obj * DataListItemEventArgs -> unitPublic Delegate Sub DataListItemEventHandler(sender As Object, e As DataListItemEventArgs)Parametreler
- sender
- Object
Olayın kaynağı.
DataListItemEventArgs Olay verilerini içeren bir.
Örnekler
Aşağıdaki örnekte, bir denetimdeki ItemDataBound öğelerin DataList fiyatını hesaplamak için olay için bir işleyicinin nasıl tanımlanacağı gösterilmektedir. Bu örnek, denetimdeki özniteliği DataList için olay işleyicisini ayarlayarak olay işleyicisini OnItemDataBound bildirim temelli olarak belirtir.
<%@ 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 DataList 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 < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Description for 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)
{
ItemsList.DataSource = CreateDataSource();
ItemsList.DataBind();
}
}
void Item_Bound(Object sender, DataListItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
// Retrieve the Label control in the current DataListItem.
Label PriceLabel = (Label)e.Item.FindControl("PriceLabel");
// Retrieve the text of the CurrencyColumn from the DataListItem
// and convert the value to a Double.
Double Price = Convert.ToDouble(
((DataRowView)e.Item.DataItem).Row.ItemArray[2].ToString());
// Format the value as currency and redisplay it in the DataList.
PriceLabel.Text = Price.ToString("c");
}
}
</script>
<head runat="server">
<title>DataList ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList ItemDataBound Example</h3>
<asp:DataList id="ItemsList"
BorderColor="black"
CellPadding="5"
CellSpacing="5"
RepeatDirection="Vertical"
RepeatLayout="Table"
RepeatColumns="3"
OnItemDataBound="Item_Bound"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<HeaderTemplate>
List of items
</HeaderTemplate>
<ItemTemplate>
Description: <br />
<%# DataBinder.Eval(Container.DataItem, "StringValue") %>
<br />
Price:
<asp:Label id="PriceLabel"
runat="server"/>
</ItemTemplate>
</asp:DataList>
</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 DataList 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 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Description for 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
ItemsList.DataSource = CreateDataSource()
ItemsList.DataBind()
End If
End Sub
Sub Item_Bound(sender As Object, e As DataListItemEventArgs)
If e.Item.ItemType = ListItemType.Item Or _
e.Item.ItemType = ListItemType.AlternatingItem Then
' Retrieve the Label control in the current DataListItem.
Dim PriceLabel As Label = _
CType(e.Item.FindControl("PriceLabel"), Label)
' Retrieve the text of the CurrencyColumn from the DataListItem
' and convert the value to a Double.
Dim Price As Double = Convert.ToDouble( _
(CType(e.Item.DataItem, DataRowView)).Row.ItemArray(2).ToString())
' Format the value as currency and redisplay it in the DataList.
PriceLabel.Text = Price.ToString("c")
End If
End Sub
</script>
<head runat="server">
<title>DataList ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList ItemDataBound Example</h3>
<asp:DataList id="ItemsList"
BorderColor="black"
CellPadding="5"
CellSpacing="5"
RepeatDirection="Vertical"
RepeatLayout="Table"
RepeatColumns="3"
OnItemDataBound="Item_Bound"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<HeaderTemplate>
List of items
</HeaderTemplate>
<ItemTemplate>
Description: <br />
<%# DataBinder.Eval(Container.DataItem, "StringValue") %>
<br />
Price:
<asp:Label id="PriceLabel"
runat="server"/>
</ItemTemplate>
</asp:DataList>
</form>
</body>
</html>
Aşağıdaki kod örneği, olay işleyicisinin nasıl belirtileceğini ve yöntemindeki Page_Load olaya program aracılığıyla nasıl ekleneceğini ItemDataBound gösterir.
<%@ 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 DataList 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 < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = "Description for 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
// ItemCommand event.
ItemsList.ItemDataBound +=
new DataListItemEventHandler(this.Item_Bound);
// Load sample data only once, when the page is first loaded.
if (!IsPostBack)
{
ItemsList.DataSource = CreateDataSource();
ItemsList.DataBind();
}
}
void Item_Bound(Object sender, DataListItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item ||
e.Item.ItemType == ListItemType.AlternatingItem)
{
// Retrieve the Label control in the current DataListItem.
Label PriceLabel = (Label)e.Item.FindControl("PriceLabel");
// Retrieve the text of the CurrencyColumn from the DataListItem
// and convert the value to a Double.
Double Price = Convert.ToDouble(
((DataRowView)e.Item.DataItem).Row.ItemArray[2].ToString());
// Format the value as currency and redisplay it in the DataList.
PriceLabel.Text = Price.ToString("c");
}
}
</script>
<head runat="server">
<title>DataList ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList ItemDataBound Example</h3>
<asp:DataList id="ItemsList"
BorderColor="black"
CellPadding="5"
CellSpacing="5"
RepeatDirection="Vertical"
RepeatLayout="Table"
RepeatColumns="3"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<HeaderTemplate>
List of items
</HeaderTemplate>
<ItemTemplate>
Description: <br />
<%# DataBinder.Eval(Container.DataItem, "StringValue") %>
<br />
Price:
<asp:Label id="PriceLabel"
runat="server"/>
</ItemTemplate>
</asp:DataList>
</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 DataList 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 8
dr = dt.NewRow()
dr(0) = i
dr(1) = "Description for 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
' ItemCommand event.
AddHandler ItemsList.ItemDataBound, AddressOf Item_Bound
' Load sample data only once, when the page is first loaded.
If Not IsPostBack Then
ItemsList.DataSource = CreateDataSource()
ItemsList.DataBind()
End If
End Sub
Sub Item_Bound(sender As Object, e As DataListItemEventArgs)
If e.Item.ItemType = ListItemType.Item Or _
e.Item.ItemType = ListItemType.AlternatingItem Then
' Retrieve the Label control in the current DataListItem.
Dim PriceLabel As Label = _
CType(e.Item.FindControl("PriceLabel"), Label)
' Retrieve the text of the CurrencyColumn from the DataListItem
' and convert the value to a Double.
Dim Price As Double = Convert.ToDouble( _
(CType(e.Item.DataItem, DataRowView)).Row.ItemArray(2).ToString())
' Format the value as currency and redisplay it in the DataList.
PriceLabel.Text = Price.ToString("c")
End If
End Sub
</script>
<head runat="server">
<title>DataList ItemDataBound Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList ItemDataBound Example</h3>
<asp:DataList id="ItemsList"
BorderColor="black"
CellPadding="5"
CellSpacing="5"
RepeatDirection="Vertical"
RepeatLayout="Table"
RepeatColumns="3"
OnItemDataBound="Item_Bound"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<HeaderTemplate>
List of items
</HeaderTemplate>
<ItemTemplate>
Description: <br />
<%# DataBinder.Eval(Container.DataItem, "StringValue") %>
<br />
Price:
<asp:Label id="PriceLabel"
runat="server"/>
</ItemTemplate>
</asp:DataList>
</form>
</body>
</html>
Açıklamalar
Denetimdeki ItemCreatedDataList bir öğe oluşturulduğunda olay oluşturulur.
Denetimdeki ItemDataBoundDataList bir öğe bir kaynağa bağlı veri olduğunda olay tetikler.
Bir DataListItemEventHandler temsilci oluşturduğunuzda, olayı işleyecek yöntemi tanımlarsınız. Olayı olay işleyicinizle ilişkilendirmek için olaya temsilcinin bir örneğini ekleyin. Olay her gerçekleştiğinde, olay işleyici (siz temsilciyi kaldırmadığınız sürece) çağrılır. Olay işleyici temsilcileri hakkında daha fazla bilgi için bkz. Olayları İşleme ve Oluşturma.
Uzantı Metotları
| GetMethodInfo(Delegate) |
Belirtilen temsilci tarafından temsil edilen yöntemi temsil eden bir nesnesi alır. |
Şunlara uygulanır
Ayrıca bkz.
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