FormView.ItemDeleting Kejadian
Definisi
Penting
Beberapa informasi terkait produk prarilis yang dapat diubah secara signifikan sebelum dirilis. Microsoft tidak memberikan jaminan, tersirat maupun tersurat, sehubungan dengan informasi yang diberikan di sini.
Terjadi saat tombol Hapus dalam FormView kontrol diklik, tetapi sebelum operasi penghapusan.
public:
event System::Web::UI::WebControls::FormViewDeleteEventHandler ^ ItemDeleting;public event System.Web.UI.WebControls.FormViewDeleteEventHandler ItemDeleting;member this.ItemDeleting : System.Web.UI.WebControls.FormViewDeleteEventHandler Public Custom Event ItemDeleting As FormViewDeleteEventHandler Jenis Acara
Contoh
Contoh berikut menunjukkan cara menggunakan ItemDeleting peristiwa untuk membatalkan operasi penghapusan.
<%@ Page language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
void EmployeeFormView_ItemDeleting(Object sender, FormViewDeleteEventArgs e)
{
// Get the employee ID, name, and job title from the Keys and Values
// properties.
String keyValue = e.Keys["EmployeeID"].ToString();
String employeeName = e.Values["FirstName"].ToString() +
" " + e.Values["LastName"].ToString();
String title = e.Values["Title"].ToString();
// Cancel the delete operation if the user attempts to
// delete a protected record. In this example, records for
// employees with a "Sales Manager" job title are protected.
if (title.Equals("Sales Manager"))
{
e.Cancel = true;
MessageLabel.Text = "You cannot delete record " +
e.RowIndex.ToString() + ". " + employeeName +
" (Employee Number " + keyValue.ToString() +
") is protected.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FormViewDeleteEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>FormViewDeleteEventArgs Example</h3>
<asp:formview id="EmployeeFormView"
datasourceid="EmployeeSource"
allowpaging="true"
datakeynames="EmployeeID"
onitemdeleting="EmployeeFormView_ItemDeleting"
runat="server">
<itemtemplate>
<table>
<tr>
<td>
<asp:image id="EmployeeImage"
imageurl='<%# Eval("PhotoPath") %>'
alternatetext='<%# Eval("LastName") %>'
runat="server"/>
</td>
<td>
<asp:label id="FirstNameLabel"
text='<%#Bind("FirstName")%>'
font-bold="true"
runat="server"/>
<asp:label id="LastNameLabel"
text='<%#Bind("LastName")%>'
font-bold="true"
runat="server"/>
<br/>
<asp:label id="TitleLabel"
text='<%#Bind("Title")%>'
runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:button id="DeleteButton"
text="Delete Record"
commandname="Delete"
runat="server" />
</td>
</tr>
</table>
</itemtemplate>
</asp:formview>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="EmployeeSource"
selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
deletecommand="Delete [Employees] Where [EmployeeID]=@EmployeeID"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
<%@ Page language="VB" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub EmployeeFormView_ItemDeleting(ByVal sender As Object, ByVal e As FormViewDeleteEventArgs)
' Get the employee ID, name, and job title from the Keys and Values
' properties.
Dim keyValue As String = e.Keys("EmployeeID").ToString()
Dim employeeName As String = e.Values("FirstName").ToString() & _
" " & e.Values("LastName").ToString()
Dim title As String = e.Values("Title").ToString()
' Cancel the delete operation if the user attempts to
' delete a protected record. In this example, records for
' employees with a "Sales Manager" job title are protected.
If Title.Equals("Sales Manager") Then
e.Cancel = True
MessageLabel.Text = "You cannot delete record " & _
e.RowIndex.ToString() & ". " & employeeName & _
" (Employee Number " & keyValue.ToString() & _
") is protected."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>FormViewDeleteEventArgs Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>FormViewDeleteEventArgs Example</h3>
<asp:formview id="EmployeeFormView"
datasourceid="EmployeeSource"
allowpaging="true"
datakeynames="EmployeeID"
onitemdeleting="EmployeeFormView_ItemDeleting"
runat="server">
<itemtemplate>
<table>
<tr>
<td>
<asp:image id="EmployeeImage"
imageurl='<%# Eval("PhotoPath") %>'
alternatetext='<%# Eval("LastName") %>'
runat="server"/>
</td>
<td>
<asp:label id="FirstNameLabel"
text='<%#Bind("FirstName")%>'
font-bold="true"
runat="server"/>
<asp:label id="LastNameLabel"
text='<%#Bind("LastName")%>'
font-bold="true"
runat="server"/>
<br/>
<asp:label id="TitleLabel"
text='<%#Bind("Title")%>'
runat="server"/>
</td>
</tr>
<tr>
<td colspan="2">
<asp:button id="DeleteButton"
text="Delete Record"
commandname="Delete"
runat="server" />
</td>
</tr>
</table>
</itemtemplate>
</asp:formview>
<asp:label id="MessageLabel"
forecolor="Red"
runat="server"/>
<!-- This example uses Microsoft SQL Server and connects -->
<!-- to the Northwind sample database. Use an ASP.NET -->
<!-- expression to retrieve the connection string value -->
<!-- from the Web.config file. -->
<asp:sqldatasource id="EmployeeSource"
selectcommand="Select [EmployeeID], [LastName], [FirstName], [Title], [PhotoPath] From [Employees]"
deletecommand="Delete [Employees] Where [EmployeeID]=@EmployeeID"
connectionstring="<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Keterangan
FormView Kontrol menaikkan ItemDeleting peristiwa saat tombol Hapus (tombol dengan propertinya CommandName diatur ke "Hapus") dalam kontrol diklik, tetapi sebelum FormView kontrol menghapus rekaman. Ini memungkinkan Anda untuk menyediakan metode penanganan peristiwa yang melakukan rutinitas kustom, seperti memverifikasi rekaman sebelum menghapusnya, setiap kali peristiwa ini terjadi.
Objek FormViewDeleteEventArgs diteruskan ke metode penanganan peristiwa, yang memungkinkan Anda menentukan indeks rekaman yang dihapus dan untuk menunjukkan bahwa operasi penghapusan harus dibatalkan. Untuk menentukan indeks rekaman, gunakan RowIndex properti . Untuk membatalkan operasi penghapusan, atur properti ke Canceltrue. Anda juga dapat mengakses bidang kunci dan bidang non-kunci dengan menggunakan Keys properti dan Values .
Untuk informasi selengkapnya tentang cara menangani peristiwa, lihat Menangani dan Menaikkan Peristiwa.
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