DataList.ItemCommand Událost
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Nastane při kliknutí na libovolné tlačítko v ovládacím DataList prvku.
public:
event System::Web::UI::WebControls::DataListCommandEventHandler ^ ItemCommand;
public event System.Web.UI.WebControls.DataListCommandEventHandler ItemCommand;
member this.ItemCommand : System.Web.UI.WebControls.DataListCommandEventHandler
Public Custom Event ItemCommand As DataListCommandEventHandler
Event Type
Příklady
Následující příklad kódu ukazuje, jak určit a kód obslužné rutiny ItemCommand pro událost vybrat položku z DataList ovládacího prvku.
Poznámka
Následující ukázka kódu používá model kódu s jedním souborem a nemusí správně fungovat, pokud je zkopírován přímo do souboru kódu na pozadí. Tento vzorový kód musí být zkopírován do prázdného textového souboru s příponou .aspx. Další informace o modelu kódu webových formulářů najdete v tématu ASP.NET model kódu stránky webových formulářů.
<%@ 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" >
<head>
<title>DataList Select Example</title>
<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("Item", typeof(Int32)));
dt.Columns.Add(new DataColumn("Qty", typeof(Int32)));
dt.Columns.Add(new DataColumn("Price", typeof(double)));
// Populate the table with sample values.
for (int i = 0; i < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = i * 2;
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_Command(Object sender, DataListCommandEventArgs e)
{
// Set the SelectedIndex property to select an item in the DataList.
ItemsList.SelectedIndex = e.Item.ItemIndex;
// Rebind the data source to the DataList to refresh the control.
ItemsList.DataSource = CreateDataSource();
ItemsList.DataBind();
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList Select Example</h3>
Click <b>Select</b> to select an item.
<br /><br />
<asp:DataList id="ItemsList"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
OnItemCommand="Item_Command"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<SelectedItemStyle BackColor="Yellow">
</SelectedItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
<asp:LinkButton id="SelectButton"
Text="Select"
CommandName="Select"
runat="server"/>
Item <%# DataBinder.Eval(Container.DataItem, "Item") %>
</ItemTemplate>
<SelectedItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br />
Quantity:
<asp:Label id="QtyLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br />
Price:
<asp:Label id="PriceLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
</SelectedItemTemplate>
</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" >
<head>
<title>DataList Select Example</title>
<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("Item", GetType(Int32)))
dt.Columns.Add(New DataColumn("Qty", GetType(Int32)))
dt.Columns.Add(New DataColumn("Price", 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) = i * 2
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_Command(sender As Object, e As DataListCommandEventArgs)
' Set the SelectedIndex property to select an item in the DataList.
ItemsList.SelectedIndex = e.Item.ItemIndex
' Rebind the data source to the DataList to refresh the control.
ItemsList.DataSource = CreateDataSource()
ItemsList.DataBind()
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList Select Example</h3>
Click <b>Select</b> to select an item.
<br /><br />
<asp:DataList id="ItemsList"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
OnItemCommand="Item_Command"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<SelectedItemStyle BackColor="Yellow">
</SelectedItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
<asp:LinkButton id="SelectButton"
Text="Select"
CommandName="Select"
runat="server"/>
Item <%# DataBinder.Eval(Container.DataItem, "Item") %>
</ItemTemplate>
<SelectedItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br />
Quantity:
<asp:Label id="QtyLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br />
Price:
<asp:Label id="PriceLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
</SelectedItemTemplate>
</asp:DataList>
</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" >
<head>
<title>DataList Select Example</title>
<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("Item", typeof(Int32)));
dt.Columns.Add(new DataColumn("Qty", typeof(Int32)));
dt.Columns.Add(new DataColumn("Price", typeof(double)));
// Populate the table with sample values.
for (int i = 0; i < 9; i++)
{
dr = dt.NewRow();
dr[0] = i;
dr[1] = i * 2;
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();
}
// Manually register the event-handling method for the
// ItemCommand event.
ItemsList.ItemCommand +=
new DataListCommandEventHandler(this.Item_Command);
}
void Item_Command(Object sender, DataListCommandEventArgs e)
{
// Set the SelectedIndex property to select an item in the DataList.
ItemsList.SelectedIndex = e.Item.ItemIndex;
// Rebind the data source to the DataList to refresh the control.
ItemsList.DataSource = CreateDataSource();
ItemsList.DataBind();
}
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList Select Example</h3>
Click <b>Select</b> to select an item.
<br /><br />
<asp:DataList id="ItemsList"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<SelectedItemStyle BackColor="Yellow">
</SelectedItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
<asp:LinkButton id="SelectButton"
Text="Select"
CommandName="Select"
runat="server"/>
Item <%# DataBinder.Eval(Container.DataItem, "Item") %>
</ItemTemplate>
<SelectedItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br />
Quantity:
<asp:Label id="QtyLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br />
Price:
<asp:Label id="PriceLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
</SelectedItemTemplate>
</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" >
<head>
<title>DataList Select Example</title>
<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("Item", GetType(Int32)))
dt.Columns.Add(New DataColumn("Qty", GetType(Int32)))
dt.Columns.Add(New DataColumn("Price", 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) = i * 2
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
' Manually register the event-handling method for the
' ItemCommand event.
AddHandler ItemsList.ItemCommand, AddressOf Item_Command
End Sub
Sub Item_Command(sender As Object, e As DataListCommandEventArgs)
' Set the SelectedIndex property to select an item in the DataList.
ItemsList.SelectedIndex = e.Item.ItemIndex
' Rebind the data source to the DataList to refresh the control.
ItemsList.DataSource = CreateDataSource()
ItemsList.DataBind()
End Sub
</script>
</head>
<body>
<form id="form1" runat="server">
<h3>DataList Select Example</h3>
Click <b>Select</b> to select an item.
<br /><br />
<asp:DataList id="ItemsList"
GridLines="Both"
CellPadding="3"
CellSpacing="0"
OnItemCommand="Item_Command"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<SelectedItemStyle BackColor="Yellow">
</SelectedItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
<asp:LinkButton id="SelectButton"
Text="Select"
CommandName="Select"
runat="server"/>
Item <%# DataBinder.Eval(Container.DataItem, "Item") %>
</ItemTemplate>
<SelectedItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br />
Quantity:
<asp:Label id="QtyLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br />
Price:
<asp:Label id="PriceLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
</SelectedItemTemplate>
</asp:DataList>
</form>
</body>
</html>
Poznámky
Událost ItemCommand se vyvolá při kliknutí na libovolné tlačítko v ovládacím DataList prvku a běžně se používá, když máte ovládací prvek tlačítko s vlastní CommandName
hodnotou.
Další informace o zpracování událostí najdete v tématu Postupy: Využití událostí v aplikaci webových formulářů.