DataList.OnCancelCommand(DataListCommandEventArgs) Yöntem
Tanım
Önemli
Bazı bilgiler ürünün ön sürümüyle ilgilidir ve sürüm öncesinde önemli değişiklikler yapılmış olabilir. Burada verilen bilgilerle ilgili olarak Microsoft açık veya zımni hiçbir garanti vermez.
Olayı tetikler CancelCommand . Bu, olay için özel bir işleyici sağlamanıza olanak tanır.
protected:
virtual void OnCancelCommand(System::Web::UI::WebControls::DataListCommandEventArgs ^ e);protected virtual void OnCancelCommand (System.Web.UI.WebControls.DataListCommandEventArgs e);abstract member OnCancelCommand : System.Web.UI.WebControls.DataListCommandEventArgs -> unit
override this.OnCancelCommand : System.Web.UI.WebControls.DataListCommandEventArgs -> unitProtected Overridable Sub OnCancelCommand (e As DataListCommandEventArgs)Parametreler
DataListCommandEventArgs Olay verilerini içeren bir.
Örnekler
Aşağıdaki kod örneği, olay için bir işleyicinin nasıl belirtileceğini ve kodleneceğini CancelCommand gösterir. Düğmeye tıklandığında Cancel denetimdeki bir öğede DataList yapılan düzenlemeleri iptal eder.
Not
Aşağıdaki kod örneği tek dosyalı kod modelini kullanır ve doğrudan arka planda kod dosyasına kopyalandığında düzgün çalışmayabilir. Bu kod örneği, .aspx uzantısına sahip boş bir metin dosyasına kopyalanmalıdır. Web Forms kod modeli hakkında daha fazla bilgi için bkz. ASP.NET Web Forms Sayfa Kodu Modeli.
<%@ 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 Edit Example</title>
<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 id="form1" 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" %>
<!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 Edit Example</title>
<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 id="form1" 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" %>
<!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 Edit Example</title>
<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 id="form1" 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>
<%@ 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 Edit Example</title>
<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 id="form1" 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>
Açıklamalar
OnCancelCommand Olay için özel bir işleyici sağlamak için CancelCommand yöntemini kullanın.
Denetimdeki CancelCommand bir öğe DataList için düğmeye Cancel tıklandığında olay tetikler.
Olay için CancelCommand tipik bir işleyici özelliği -1 olarak ayarlar EditItemIndex (öğenin seçimini kaldırmak için) ve ardından verileri denetime DataList yeniden ekler.
Dikkat
Bu denetim, kötü amaçlı istemci betiği içerebilecek kullanıcı girişini görüntülemek için kullanılabilir. Uygulamanızda görüntülemeden önce bir istemciden yürütülebilir betik, SQL deyimleri veya başka bir kod için gönderilen tüm bilgileri denetleyin. Denetimde giriş metnini görüntülemeden önce kullanıcı girişini doğrulamak için doğrulama denetimlerini kullanabilirsiniz. ASP.NET, kullanıcı girişinde betiği ve HTML'yi engellemek için bir giriş isteği doğrulama özelliği sağlar. Daha fazla bilgi için bkz. Standart Denetimlerin Güvenliğini Sağlama, Nasıl yapılır: Dizelere HTML Kodlaması Uygulayarak ve ASP.NET Web Sayfalarında Kullanıcı Girişini Doğrulayarak Web Uygulamasında Betik Açıklarından Yararlanmaya Karşı Koruma.
Olay bildirmek, bir temsilci yoluyla olay işleyicisini çağırır. Daha fazla bilgi için bkz . Nasıl yapılır: Web Forms Uygulamasında Olayları Kullanma.
yöntemi, OnCancelCommand türetilmiş sınıfların bir temsilci eklemeden olayı işlemesine de izin verir. Bu, türetilmiş bir sınıftaki olayı işlemek için tercih edilen tekniktir.
Devralanlara Notlar
Türetilmiş bir sınıfta geçersiz kıldığınızda OnCancelCommand(DataListCommandEventArgs) , kayıtlı temsilcilerin olayı alması için temel sınıfın OnCancelCommand(DataListCommandEventArgs) yöntemini çağırdığınızdan emin olun.
Şunlara uygulanır
Ayrıca bkz.
- CancelCommand
- OnDeleteCommand(DataListCommandEventArgs)
- OnEditCommand(DataListCommandEventArgs)
- OnUpdateCommand(DataListCommandEventArgs)
- DataListCommandEventArgs
- Standart Denetimlerin Güvenliğini Sağlama
- Nasıl yapılır: Dizelere HTML Kodlaması Uygulayarak Bir Web Uygulamasında Betik Açıklarından Korunma
- ASP.NET Web Sayfalarında Kullanıcı Girişini Doğrulamaya Giriş
GitHub'da bizimle işbirliği yapın
Bu içeriğin kaynağı GitHub'da bulunabilir; burada ayrıca sorunları ve çekme isteklerini oluşturup gözden geçirebilirsiniz. Daha fazla bilgi için katkıda bulunan kılavuzumuzu inceleyin.
