DataList.OnDeleteCommand-Methode
Löst das DeleteCommand-Ereignis aus. Dadurch können Sie einen benutzerdefinierten Handler für das Ereignis bereitstellen.
Namespace: System.Web.UI.WebControls
Assembly: System.Web (in system.web.dll)
Syntax
'Declaration
Protected Overridable Sub OnDeleteCommand ( _
e As DataListCommandEventArgs _
)
'Usage
Dim e As DataListCommandEventArgs
Me.OnDeleteCommand(e)
protected virtual void OnDeleteCommand (
DataListCommandEventArgs e
)
protected:
virtual void OnDeleteCommand (
DataListCommandEventArgs^ e
)
protected void OnDeleteCommand (
DataListCommandEventArgs e
)
protected function OnDeleteCommand (
e : DataListCommandEventArgs
)
Parameter
- e
Eine Instanz von DataListCommandEventArgs, die die Ereignisdaten enthält.
Hinweise
Mit der OnDeleteCommand-Methode können Sie für das DeleteCommand-Ereignis einen benutzerdefinierten Handler bereitstellen.
Das DeleteCommand-Ereignis wird ausgelöst, wenn für ein Element im DataList-Steuerelement auf die Schaltfläche Delete geklickt wird.
Ein typischer Handler für das DeleteCommand-Ereignis entfernt das ausgewählte Element aus der Datenquelle und bindet die Daten dann erneut an das DataList-Steuerelement.
Durch das Auslösen eines Ereignisses wird der Ereignishandler über einen Delegaten aufgerufen. Weitere Informationen finden Sie unter Gewusst wie: Verarbeiten von Ereignissen in einer Web Forms-Anwendung.
Die OnDeleteCommand-Methode ermöglicht es auch abgeleiteten Klassen, das Ereignis ohne Anfügen eines Delegaten zu behandeln. Dies ist das bevorzugte Verfahren für die Behandlung des Ereignisses in einer abgeleiteten Klasse.
Hinweise für Erben Wenn Sie OnDeleteCommand in einer abgeleiteten Klasse überschreiben, müssen Sie die OnDeleteCommand-Methode der Basisklasse aufrufen, sodass registrierte Delegaten das Ereignis empfangen.
Beispiel
Im folgenden Codebeispiel wird das Angeben und Codieren eines Handlers für das DeleteCommand-Ereignis veranschaulicht. Dieser löscht das im DataList-Steuerelement ausgewählte Element, wenn auf die Schaltfläche Delete geklickt wird.
Hinweis
Im folgenden Codebeispiel wird das Einzeldatei-Codemodell verwendet. Das Beispiel funktioniert möglicherweise nicht, wenn es direkt in eine CodeBehind-Datei kopiert wird. Dieses Codebeispiel muss in eine leere Textdatei mit einer ASPX-Erweiterung kopiert werden. Weitere Informationen zum Web Forms-Codemodell finden Sie unter Codemodell für ASP.NET-Webseiten.
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<head>
<script runat="server">
' The Cart and CartView objects temporarily store the data source
' for the DataList control while the page is being processed.
Dim Cart As DataTable = New DataTable()
Dim CartView As DataView
Sub Page_Load(sende As Object, e As EventArgs)
' With a database, use an select query to retrieve the data.
' Because the data source in this example is an in-memory
' DataTable, retrieve the data from session state if it exists;
' otherwise, create the data source.
GetSource()
' The DataGrid control maintains state between posts to the server;
' it only needs to be bound to a data source the first time the
' page is loaded or when the data source is updated.
If Not IsPostBack Then
BindList()
End If
End Sub
Sub BindList()
' Set the data source and bind to the DataList control.
ItemsList.DataSource = CartView
ItemsList.DataBind()
End Sub
Sub GetSource()
' For this example, the data source is a DataTable that
' is stored in session state. If the data source does not exist,
' create it; otherwise, load the data.
If Session("ShoppingCart") Is Nothing Then
' Create the sample data.
Dim dr As DataRow
' Define the columns of the table.
Cart.Columns.Add(new DataColumn("Qty", GetType(Int32)))
Cart.Columns.Add(new DataColumn("Item", GetType(String)))
Cart.Columns.Add(new DataColumn("Price", GetType(Double)))
' Store the table in session state to persist its values
' between posts to the server.
Session("ShoppingCart") = Cart
' Populate the DataTable with sample data.
Dim i As Integer
For i = 1 To 9
dr = Cart.NewRow()
If (i Mod 2) <> 0 Then
dr(0) = 2
Else
dr(0) = 1
End If
dr(1) = "Item " & i.ToString()
dr(2) = (1.23 * (i + 1))
Cart.Rows.Add(dr)
Next i
Else
' Retrieve the sample data from session state.
Cart = CType(Session("ShoppingCart"), DataTable)
End If
' Create a DataView and specify the field to sort by.
CartView = New DataView(Cart)
CartView.Sort="Item"
Return
End Sub
Sub Edit_Command(sender As Object, e As DataListCommandEventArgs)
' Set the EditItemIndex property to the index of the item clicked
' in the DataList control to enable editing for that item. Be sure
' to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = e.Item.ItemIndex
BindList()
End Sub
Sub Cancel_Command(sender As Object, e As DataListCommandEventArgs)
' Set the EditItemIndex property to -1 to exit editing mode. Be sure
' to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1
BindList()
End Sub
Sub Delete_Command(sender As Object, e As DataListCommandEventArgs)
' Retrieve the name of the item to remove.
Dim item As String = (CType(e.Item.FindControl("ItemLabel"), Label)).Text
' Filter the CartView for the selected item and remove it from
' the data source.
CartView.RowFilter = "Item='" & item & "'"
If CartView.Count > 0 Then
CartView.Delete(0)
End If
CartView.RowFilter = ""
' Set the EditItemIndex property to -1 to exit editing mode. Be sure
' to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1
BindList()
End Sub
Sub Update_Command(sender As Object, e As DataListCommandEventArgs)
' Retrieve the updated values from the selected item.
Dim item As String = _
(CType(e.Item.FindControl("ItemLabel"), Label)).Text
Dim qty As String = _
(CType(e.Item.FindControl("QtyTextBox"), TextBox)).Text
Dim price As String = _
(CType(e.Item.FindControl("PriceTextBox"), TextBox)).Text
' With a database, use an update command to update the data.
' Because the data source in this example is an in-memory
' DataTable, delete the old row and replace it with a new one.
' Filter the CartView for the selected item and remove it from
' the data source.
CartView.RowFilter = "Item='" & item & "'"
If CartView.Count > 0 Then
CartView.Delete(0)
End If
CartView.RowFilter = ""
' ***************************************************************
' Insert data validation code here. Make sure to validate the
' values entered by the user before converting to the appropriate
' data types and updating the data source.
' ***************************************************************
' Add a new entry to replace the previous item.
Dim dr As DataRow = Cart.NewRow()
dr(0) = qty
dr(1) = item
' If necessary, remove the '$' character from the price before
' converting the price to a Double.
If price.Chars(0) = "$" Then
dr(2) = Convert.ToDouble(price.Substring(1))
Else
dr(2) = Convert.ToDouble(price)
End If
Cart.Rows.Add(dr)
' Set the EditItemIndex property to -1 to exit editing mode.
' Be sure to rebind the DataList to the data source to refresh
' the control.
ItemsList.EditItemIndex = -1
BindList()
End Sub
</script>
</head>
<body>
<form runat=server>
<h3>DataList Edit Example</h3>
Click <b>Edit</b> to edit the values of the item.
<br><br>
<asp:DataList id="ItemsList"
GridLines="Both"
RepeatColumns="3"
RepeatDirection="Horizontal"
CellPadding="3"
CellSpacing="0"
OnEditCommand="Edit_Command"
OnUpdateCommand="Update_Command"
OnDeleteCommand="Delete_Command"
OnCancelCommand="Cancel_Command"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<EditItemStyle BackColor="yellow">
</EditItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
Item:
<%# DataBinder.Eval(Container.DataItem, "Item") %>
<br>
Quantity:
<%# DataBinder.Eval(Container.DataItem, "Qty") %>
<br>
Price:
<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>
<br>
<asp:LinkButton id="EditButton"
Text="Edit"
CommandName="Edit"
runat="server"/>
</ItemTemplate>
<EditItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br>
Quantity:
<asp:TextBox id="QtyTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br>
Price:
<asp:TextBox id="PriceTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
<br>
<asp:LinkButton id="UpdateButton"
Text="Update"
CommandName="Update"
runat="server"/>
<asp:LinkButton id="DeleteButton"
Text="Delete"
CommandName="Delete"
runat="server"/>
<asp:LinkButton id="CancelButton"
Text="Cancel"
CommandName="Cancel"
runat="server"/>
</EditItemTemplate>
</asp:DataList>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<head>
<script runat="server">
// The Cart and CartView objects temporarily store the data source
// for the DataList control while the page is being processed.
DataTable Cart = new DataTable();
DataView CartView;
void Page_Load(Object sender, EventArgs e)
{
// With a database, use an select query to retrieve the data.
// Because the data source in this example is an in-memory
// DataTable, retrieve the data from session state if it exists;
// otherwise, create the data source.
GetSource();
// The DataList control maintains state between posts to the server;
// it only needs to be bound to a data source the first time the
// page is loaded or when the data source is updated.
if (!IsPostBack)
{
BindList();
}
}
void BindList()
{
// Set the data source and bind to the DataList control.
ItemsList.DataSource = CartView;
ItemsList.DataBind();
}
void GetSource()
{
// For this example, the data source is a DataTable that
// is stored in session state. If the data source does not exist,
// create it; otherwise, load the data.
if (Session["ShoppingCart"] == null)
{
// Create the sample data.
DataRow dr;
// Define the columns of the table.
Cart.Columns.Add(new DataColumn("Qty", typeof(Int32)));
Cart.Columns.Add(new DataColumn("Item", typeof(String)));
Cart.Columns.Add(new DataColumn("Price", typeof(Double)));
// Store the table in session state to persist its values
// between posts to the server.
Session["ShoppingCart"] = Cart;
// Populate the DataTable with sample data.
for (int i = 1; i <= 9; i++)
{
dr = Cart.NewRow();
if (i % 2 != 0)
{
dr[0] = 2;
}
else
{
dr[0] = 1;
}
dr[1] = "Item " + i.ToString();
dr[2] = (1.23 * (i + 1));
Cart.Rows.Add(dr);
}
}
else
{
// Retrieve the sample data from session state.
Cart = (DataTable)Session["ShoppingCart"];
}
// Create a DataView and specify the field to sort by.
CartView = new DataView(Cart);
CartView.Sort="Item";
return;
}
void Edit_Command(Object sender, DataListCommandEventArgs e)
{
// Set the EditItemIndex property to the index of the item clicked
// in the DataList control to enable editing for that item. Be sure
// to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = e.Item.ItemIndex;
BindList();
}
void Cancel_Command(Object sender, DataListCommandEventArgs e)
{
// Set the EditItemIndex property to -1 to exit editing mode. Be sure
// to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1;
BindList();
}
void Delete_Command(Object sender, DataListCommandEventArgs e)
{
// Retrieve the name of the item to remove.
String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
// Filter the CartView for the selected item and remove it from
// the data source.
CartView.RowFilter = "Item='" + item + "'";
if (CartView.Count > 0)
{
CartView.Delete(0);
}
CartView.RowFilter = "";
// Set the EditItemIndex property to -1 to exit editing mode. Be sure
// to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1;
BindList();
}
void Update_Command(Object sender, DataListCommandEventArgs e)
{
// Retrieve the updated values from the selected item.
String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
String qty = ((TextBox)e.Item.FindControl("QtyTextBox")).Text;
String price = ((TextBox)e.Item.FindControl("PriceTextBox")).Text;
// With a database, use an update command to update the data.
// Because the data source in this example is an in-memory
// DataTable, delete the old row and replace it with a new one.
// Filter the CartView for the selected item and remove it from
// the data source.
CartView.RowFilter = "Item='" + item + "'";
if (CartView.Count > 0)
{
CartView.Delete(0);
}
CartView.RowFilter = "";
// ***************************************************************
// Insert data validation code here. Make sure to validate the
// values entered by the user before converting to the appropriate
// data types and updating the data source.
// ***************************************************************
// Add a new entry to replace the previous item.
DataRow dr = Cart.NewRow();
dr[0] = qty;
dr[1] = item;
// If necessary, remove the '$' character from the price before
// converting the price to a Double.
if(price[0] == '$')
{
dr[2] = Convert.ToDouble(price.Substring(1));
}
else
{
dr[2] = Convert.ToDouble(price);
}
Cart.Rows.Add(dr);
// Set the EditItemIndex property to -1 to exit editing mode.
// Be sure to rebind the DataList to the data source to refresh
// the control.
ItemsList.EditItemIndex = -1;
BindList();
}
</script>
</head>
<body>
<form runat=server>
<h3>DataList Edit Example</h3>
Click <b>Edit</b> to edit the values of the item.
<br><br>
<asp:DataList id="ItemsList"
GridLines="Both"
RepeatColumns="3"
RepeatDirection="Horizontal"
CellPadding="3"
CellSpacing="0"
OnEditCommand="Edit_Command"
OnUpdateCommand="Update_Command"
OnDeleteCommand="Delete_Command"
OnCancelCommand="Cancel_Command"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<EditItemStyle BackColor="yellow">
</EditItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
Item:
<%# DataBinder.Eval(Container.DataItem, "Item") %>
<br>
Quantity:
<%# DataBinder.Eval(Container.DataItem, "Qty") %>
<br>
Price:
<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>
<br>
<asp:LinkButton id="EditButton"
Text="Edit"
CommandName="Edit"
runat="server"/>
</ItemTemplate>
<EditItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br>
Quantity:
<asp:TextBox id="QtyTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br>
Price:
<asp:TextBox id="PriceTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
<br>
<asp:LinkButton id="UpdateButton"
Text="Update"
CommandName="Update"
runat="server"/>
<asp:LinkButton id="DeleteButton"
Text="Delete"
CommandName="Delete"
runat="server"/>
<asp:LinkButton id="CancelButton"
Text="Cancel"
CommandName="Cancel"
runat="server"/>
</EditItemTemplate>
</asp:DataList>
</form>
</body>
</html>
<%@ Page Language="VB" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<head>
<script runat="server">
' The Cart and CartView objects temporarily store the data source
' for the DataList control while the page is being processed.
Dim Cart As DataTable = New DataTable()
Dim CartView As DataView
Sub Page_Load(sende As Object, e As EventArgs)
' With a database, use an select query to retrieve the data.
' Because the data source in this example is an in-memory
' DataTable, retrieve the data from session state if it exists;
' otherwise, create the data source.
GetSource()
' The DataGrid control maintains state between posts to the server;
' it only needs to be bound to a data source the first time the
' page is loaded or when the data source is updated.
If Not IsPostBack Then
BindList()
End If
' Manually register the event-handling methods.
AddHandler ItemsList.EditCommand, AddressOf Edit_Command
AddHandler ItemsList.UpdateCommand, AddressOf Update_Command
AddHandler ItemsList.DeleteCommand, AddressOf Delete_Command
AddHandler ItemsList.CancelCommand, AddressOf Cancel_Command
End Sub
Sub BindList()
' Set the data source and bind to the DataList control.
ItemsList.DataSource = CartView
ItemsList.DataBind()
End Sub
Sub GetSource()
' For this example, the data source is a DataTable that
' is stored in session state. If the data source does not exist,
' create it; otherwise, load the data.
If Session("ShoppingCart") Is Nothing Then
' Create the sample data.
Dim dr As DataRow
' Define the columns of the table.
Cart.Columns.Add(new DataColumn("Qty", GetType(Int32)))
Cart.Columns.Add(new DataColumn("Item", GetType(String)))
Cart.Columns.Add(new DataColumn("Price", GetType(Double)))
' Store the table in session state to persist its values
' between posts to the server.
Session("ShoppingCart") = Cart
' Populate the DataTable with sample data.
Dim i As Integer
For i = 1 To 9
dr = Cart.NewRow()
If (i Mod 2) <> 0 Then
dr(0) = 2
Else
dr(0) = 1
End If
dr(1) = "Item " & i.ToString()
dr(2) = (1.23 * (i + 1))
Cart.Rows.Add(dr)
Next i
Else
' Retrieve the sample data from session state.
Cart = CType(Session("ShoppingCart"), DataTable)
End If
' Create a DataView and specify the field to sort by.
CartView = New DataView(Cart)
CartView.Sort="Item"
Return
End Sub
Sub Edit_Command(sender As Object, e As DataListCommandEventArgs)
' Set the EditItemIndex property to the index of the item clicked
' in the DataList control to enable editing for that item. Be sure
' to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = e.Item.ItemIndex
BindList()
End Sub
Sub Cancel_Command(sender As Object, e As DataListCommandEventArgs)
' Set the EditItemIndex property to -1 to exit editing mode. Be sure
' to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1
BindList()
End Sub
Sub Delete_Command(sender As Object, e As DataListCommandEventArgs)
' Retrieve the name of the item to remove.
Dim item As String = (CType(e.Item.FindControl("ItemLabel"), Label)).Text
' Filter the CartView for the selected item and remove it from
' the data source.
CartView.RowFilter = "Item='" & item & "'"
If CartView.Count > 0 Then
CartView.Delete(0)
End If
CartView.RowFilter = ""
' Set the EditItemIndex property to -1 to exit editing mode. Be sure
' to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1
BindList()
End Sub
Sub Update_Command(sender As Object, e As DataListCommandEventArgs)
' Retrieve the updated values from the selected item.
Dim item As String = _
(CType(e.Item.FindControl("ItemLabel"), Label)).Text
Dim qty As String = _
(CType(e.Item.FindControl("QtyTextBox"), TextBox)).Text
Dim price As String = _
(CType(e.Item.FindControl("PriceTextBox"), TextBox)).Text
' With a database, use an update command to update the data.
' Because the data source in this example is an in-memory
' DataTable, delete the old row and replace it with a new one.
' Filter the CartView for the selected item and remove it from
' the data source.
CartView.RowFilter = "Item='" & item & "'"
If CartView.Count > 0 Then
CartView.Delete(0)
End If
CartView.RowFilter = ""
' ***************************************************************
' Insert data validation code here. Make sure to validate the
' values entered by the user before converting to the appropriate
' data types and updating the data source.
' ***************************************************************
' Add a new entry to replace the previous item.
Dim dr As DataRow = Cart.NewRow()
dr(0) = qty
dr(1) = item
' If necessary, remove the '$' character from the price before
' converting the price to a Double.
If price.Chars(0) = "$" Then
dr(2) = Convert.ToDouble(price.Substring(1))
Else
dr(2) = Convert.ToDouble(price)
End If
Cart.Rows.Add(dr)
' Set the EditItemIndex property to -1 to exit editing mode.
' Be sure to rebind the DataList to the data source to refresh
' the control.
ItemsList.EditItemIndex = -1
BindList()
End Sub
</script>
</head>
<body>
<form runat=server>
<h3>DataList Edit Example</h3>
Click <b>Edit</b> to edit the values of the item.
<br><br>
<asp:DataList id="ItemsList"
GridLines="Both"
RepeatColumns="3"
RepeatDirection="Horizontal"
CellPadding="3"
CellSpacing="0"
OnEditCommand="Edit_Command"
OnUpdateCommand="Update_Command"
OnDeleteCommand="Delete_Command"
OnCancelCommand="Cancel_Command"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<EditItemStyle BackColor="yellow">
</EditItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
Item:
<%# DataBinder.Eval(Container.DataItem, "Item") %>
<br>
Quantity:
<%# DataBinder.Eval(Container.DataItem, "Qty") %>
<br>
Price:
<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>
<br>
<asp:LinkButton id="EditButton"
Text="Edit"
CommandName="Edit"
runat="server"/>
</ItemTemplate>
<EditItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br>
Quantity:
<asp:TextBox id="QtyTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br>
Price:
<asp:TextBox id="PriceTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
<br>
<asp:LinkButton id="UpdateButton"
Text="Update"
CommandName="Update"
runat="server"/>
<asp:LinkButton id="DeleteButton"
Text="Delete"
CommandName="Delete"
runat="server"/>
<asp:LinkButton id="CancelButton"
Text="Cancel"
CommandName="Cancel"
runat="server"/>
</EditItemTemplate>
</asp:DataList>
</form>
</body>
</html>
<%@ Page Language="C#" AutoEventWireup="True" %>
<%@ Import Namespace="System.Data" %>
<html>
<head>
<script runat="server">
// The Cart and CartView objects temporarily store the data source
// for the DataList control while the page is being processed.
DataTable Cart = new DataTable();
DataView CartView;
void Page_Load(Object sender, EventArgs e)
{
// With a database, use an select query to retrieve the data.
// Because the data source in this example is an in-memory
// DataTable, retrieve the data from session state if it exists;
// otherwise, create the data source.
GetSource();
// The DataList control maintains state between posts to the server;
// it only needs to be bound to a data source the first time the
// page is loaded or when the data source is updated.
if (!IsPostBack)
{
BindList();
}
// Manually register the event-handling methods.
ItemsList.EditCommand +=
new DataListCommandEventHandler(this.Edit_Command);
ItemsList.UpdateCommand +=
new DataListCommandEventHandler(this.Update_Command);
ItemsList.DeleteCommand +=
new DataListCommandEventHandler(this.Delete_Command);
ItemsList.CancelCommand +=
new DataListCommandEventHandler(this.Cancel_Command);
}
void BindList()
{
// Set the data source and bind to the DataList control.
ItemsList.DataSource = CartView;
ItemsList.DataBind();
}
void GetSource()
{
// For this example, the data source is a DataTable that
// is stored in session state. If the data source does not exist,
// create it; otherwise, load the data.
if (Session["ShoppingCart"] == null)
{
// Create the sample data.
DataRow dr;
// Define the columns of the table.
Cart.Columns.Add(new DataColumn("Qty", typeof(Int32)));
Cart.Columns.Add(new DataColumn("Item", typeof(String)));
Cart.Columns.Add(new DataColumn("Price", typeof(Double)));
// Store the table in session state to persist its values
// between posts to the server.
Session["ShoppingCart"] = Cart;
// Populate the DataTable with sample data.
for (int i = 1; i <= 9; i++)
{
dr = Cart.NewRow();
if (i % 2 != 0)
{
dr[0] = 2;
}
else
{
dr[0] = 1;
}
dr[1] = "Item " + i.ToString();
dr[2] = (1.23 * (i + 1));
Cart.Rows.Add(dr);
}
}
else
{
// Retrieve the sample data from session state.
Cart = (DataTable)Session["ShoppingCart"];
}
// Create a DataView and specify the field to sort by.
CartView = new DataView(Cart);
CartView.Sort="Item";
return;
}
void Edit_Command(Object sender, DataListCommandEventArgs e)
{
// Set the EditItemIndex property to the index of the item clicked
// in the DataList control to enable editing for that item. Be sure
// to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = e.Item.ItemIndex;
BindList();
}
void Cancel_Command(Object sender, DataListCommandEventArgs e)
{
// Set the EditItemIndex property to -1 to exit editing mode. Be sure
// to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1;
BindList();
}
void Delete_Command(Object sender, DataListCommandEventArgs e)
{
// Retrieve the name of the item to remove.
String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
// Filter the CartView for the selected item and remove it from
// the data source.
CartView.RowFilter = "Item='" + item + "'";
if (CartView.Count > 0)
{
CartView.Delete(0);
}
CartView.RowFilter = "";
// Set the EditItemIndex property to -1 to exit editing mode. Be sure
// to rebind the DataList to the data source to refresh the control.
ItemsList.EditItemIndex = -1;
BindList();
}
void Update_Command(Object sender, DataListCommandEventArgs e)
{
// Retrieve the updated values from the selected item.
String item = ((Label)e.Item.FindControl("ItemLabel")).Text;
String qty = ((TextBox)e.Item.FindControl("QtyTextBox")).Text;
String price = ((TextBox)e.Item.FindControl("PriceTextBox")).Text;
// With a database, use an update command to update the data.
// Because the data source in this example is an in-memory
// DataTable, delete the old row and replace it with a new one.
// Filter the CartView for the selected item and remove it from
// the data source.
CartView.RowFilter = "Item='" + item + "'";
if (CartView.Count > 0)
{
CartView.Delete(0);
}
CartView.RowFilter = "";
// ***************************************************************
// Insert data validation code here. Make sure to validate the
// values entered by the user before converting to the appropriate
// data types and updating the data source.
// ***************************************************************
// Add a new entry to replace the previous item.
DataRow dr = Cart.NewRow();
dr[0] = qty;
dr[1] = item;
// If necessary, remove the '$' character from the price before
// converting the price to a Double.
if(price[0] == '$')
{
dr[2] = Convert.ToDouble(price.Substring(1));
}
else
{
dr[2] = Convert.ToDouble(price);
}
Cart.Rows.Add(dr);
// Set the EditItemIndex property to -1 to exit editing mode.
// Be sure to rebind the DataList to the data source to refresh
// the control.
ItemsList.EditItemIndex = -1;
BindList();
}
</script>
</head>
<body>
<form runat=server>
<h3>DataList Edit Example</h3>
Click <b>Edit</b> to edit the values of the item.
<br><br>
<asp:DataList id="ItemsList"
GridLines="Both"
RepeatColumns="3"
RepeatDirection="Horizontal"
CellPadding="3"
CellSpacing="0"
runat="server">
<HeaderStyle BackColor="#aaaadd">
</HeaderStyle>
<AlternatingItemStyle BackColor="Gainsboro">
</AlternatingItemStyle>
<EditItemStyle BackColor="yellow">
</EditItemStyle>
<HeaderTemplate>
Items
</HeaderTemplate>
<ItemTemplate>
Item:
<%# DataBinder.Eval(Container.DataItem, "Item") %>
<br>
Quantity:
<%# DataBinder.Eval(Container.DataItem, "Qty") %>
<br>
Price:
<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>
<br>
<asp:LinkButton id="EditButton"
Text="Edit"
CommandName="Edit"
runat="server"/>
</ItemTemplate>
<EditItemTemplate>
Item:
<asp:Label id="ItemLabel"
Text='<%# DataBinder.Eval(Container.DataItem, "Item") %>'
runat="server"/>
<br>
Quantity:
<asp:TextBox id="QtyTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Qty") %>'
runat="server"/>
<br>
Price:
<asp:TextBox id="PriceTextBox"
Text='<%# DataBinder.Eval(Container.DataItem, "Price", "{0:c}") %>'
runat="server"/>
<br>
<asp:LinkButton id="UpdateButton"
Text="Update"
CommandName="Update"
runat="server"/>
<asp:LinkButton id="DeleteButton"
Text="Delete"
CommandName="Delete"
runat="server"/>
<asp:LinkButton id="CancelButton"
Text="Cancel"
CommandName="Cancel"
runat="server"/>
</EditItemTemplate>
</asp:DataList>
</form>
</body>
</html>
Plattformen
Windows 98, Windows 2000 SP4, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
.NET Framework unterstützt nicht alle Versionen sämtlicher Plattformen. Eine Liste der unterstützten Versionen finden Sie unter Systemanforderungen.
Versionsinformationen
.NET Framework
Unterstützt in: 2.0, 1.1, 1.0
Siehe auch
Referenz
DataList-Klasse
DataList-Member
System.Web.UI.WebControls-Namespace
DeleteCommand
OnCancelCommand
OnEditCommand
OnUpdateCommand
DataListCommandEventArgs