DetailsViewDeleteEventHandler 委托
定义
重要
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表示处理 ItemDeleting 控件的 DetailsView 事件的方法。
public delegate void DetailsViewDeleteEventHandler(System::Object ^ sender, DetailsViewDeleteEventArgs ^ e);public delegate void DetailsViewDeleteEventHandler(object sender, DetailsViewDeleteEventArgs e);type DetailsViewDeleteEventHandler = delegate of obj * DetailsViewDeleteEventArgs -> unitPublic Delegate Sub DetailsViewDeleteEventHandler(sender As Object, e As DetailsViewDeleteEventArgs)参数
- sender
- Object
事件源。
示例
下面的代码示例演示如何以编程方式向 控件的 DetailsView 事件添加DetailsViewDeleteEventHandler委托ItemDeleting。
<%@ 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 Page_Load(Object sender, EventArgs e)
{
// Create a new DetailsView object.
DetailsView customerDetailsView = new DetailsView();
// Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView";
customerDetailsView.DataSourceID = "DetailsViewSource";
customerDetailsView.AutoGenerateRows = true;
customerDetailsView.AutoGenerateDeleteButton = true;
customerDetailsView.AllowPaging = true;
customerDetailsView.PagerSettings.Mode = PagerButtons.NextPrevious;
customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };
// Programmatically register the event-handling method
// for the ItemDeleting event of a DetailsView control.
customerDetailsView.ItemDeleting += new DetailsViewDeleteEventHandler(this.CustomerDetailsView_ItemDeleting);
// Add the DetailsView object to the Controls collection
// of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView);
}
void CustomerDetailsView_ItemDeleting(Object sender, DetailsViewDeleteEventArgs e)
{
// Get customer ID and name from the Keys and Values
// properties.
String keyValue = e.Keys["CustomerID"].ToString();
String customerName = e.Values["CompanyName"].ToString();
// Cancel the delete operation if the user attempts to
// delete protected record. In this example, records
// with a customer ID that starts with with "A" cannot
// be deleted.
if (keyValue.StartsWith("A"))
{
e.Cancel = true;
MessageLabel.Text = "You cannot delete " +
customerName + ". This customer is protected.";
}
else
{
MessageLabel.Text = "Row " + e.RowIndex.ToString() +
" deleted.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewDeleteEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:PlaceHolder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
<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="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
deletecommand="Delete [Customers]
Where [CustomerID]=@CustomerID"
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 Page_Load(ByVal sender As Object, ByVal e As EventArgs)
' Create a new DetailsView object.
Dim customerDetailsView As New DetailsView()
' Set the DetailsView object's properties.
customerDetailsView.ID = "CustomerDetailsView"
customerDetailsView.DataSourceID = "DetailsViewSource"
customerDetailsView.AutoGenerateRows = True
customerDetailsView.AutoGenerateDeleteButton = True
customerDetailsView.AllowPaging = True
customerDetailsView.PagerSettings.Mode = PagerButtons.NextPrevious
Dim keyArray() As String = {"CustomerID"}
customerDetailsView.DataKeyNames = keyArray
' Programmatically register the event-handling method
' for the ItemDeleting event of a DetailsView control.
AddHandler customerDetailsView.ItemDeleting, AddressOf CustomerDetailsView_ItemDeleting
' Add the DetailsView object to the Controls collection
' of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView)
End Sub
Sub CustomerDetailsView_ItemDeleting(ByVal sender As Object, ByVal e As DetailsViewDeleteEventArgs)
' Get customer ID and name from the Keys and Values
' properties.
Dim keyValue As String = e.Keys("CustomerID").ToString()
Dim customerName As String = e.Values("CompanyName").ToString()
' Cancel the delete operation if the user attempts to
' delete protected record. In this example, records
' with a customer ID that starts with with "A" cannot
' be deleted.
If keyValue.StartsWith("A") Then
e.Cancel = True
MessageLabel.Text = "You cannot delete " & _
customerName & ". This customer is protected."
Else
MessageLabel.Text = "Row " & e.RowIndex.ToString() & _
" deleted."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewDeleteEventHandler Example</h3>
<!-- Use a PlaceHolder control as the container for the -->
<!-- dynamically generated DetailsView control. -->
<asp:PlaceHolder id="DetailsViewPlaceHolder"
runat="server"/>
<br/><br/>
<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="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
deletecommand="Delete [Customers]
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
下面的代码示例演示如何以声明方式向 控件的 DetailsView 事件添加DetailsViewDeleteEventHandler委托ItemDeleting。
<%@ 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 CustomerDetailsView_ItemDeleting(Object sender,
DetailsViewDeleteEventArgs e)
{
// Get customer ID and name from the Keys and Values
// properties.
String keyValue = e.Keys["CustomerID"].ToString();
String customerName = e.Values["CompanyName"].ToString();
// Cancel the delete operation if the user attempts to
// delete protected record. In this example, records
// with a customer ID that starts with with "A" cannot
// be deleted.
if (keyValue.StartsWith("A"))
{
e.Cancel = true;
MessageLabel.Text = "You cannot delete " +
customerName + ". This customer is protected.";
}
else
{
MessageLabel.Text = "Row " + e.RowIndex.ToString() +
" deleted.";
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewDeleteEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogeneratedeletebutton="true"
allowpaging="true"
datakeynames="CustomerID"
onitemdeleting="CustomerDetailsView_ItemDeleting"
runat="server">
<pagersettings mode="NextPrevious"/>
</asp:detailsview>
<br/><br/>
<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="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
deletecommand="Delete [Customers]
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
<%@ page language="VB" autoeventwireup="false"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Sub CustomerDetailsView_ItemDeleting(ByVal sender As Object, _
ByVal e As DetailsViewDeleteEventArgs) _
Handles CustomerDetailsView.ItemDeleting
' Get customer ID and name from the Keys and Values
' properties.
Dim keyValue As String = e.Keys("CustomerID").ToString()
Dim customerName As String = e.Values("CompanyName").ToString()
' Cancel the delete operation if the user attempts to
' delete protected record. In this example, records
' with a customer ID that starts with with "A" cannot
' be deleted.
If keyValue.StartsWith("A") Then
e.Cancel = True
MessageLabel.Text = "You cannot delete " & _
customerName & ". This customer is protected."
Else
MessageLabel.Text = "Row " & e.RowIndex.ToString() & _
" deleted."
End If
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewDeleteEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewDeleteEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogeneratedeletebutton="true"
allowpaging="true"
datakeynames="CustomerID"
runat="server">
<pagersettings mode="NextPrevious"/>
</asp:detailsview>
<br/><br/>
<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="DetailsViewSource"
selectcommand="Select [CustomerID], [CompanyName], [Address],
[City], [PostalCode], [Country] From [Customers]"
deletecommand="Delete [Customers]
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
注解
DetailsView当“删除”按钮 (控件中的属性设置为“Delete”的按钮CommandName时，控件将引发 ItemDeleting 该事件，) 在控件中删除该记录之后DetailsView单击。 这允许你提供一个事件处理程序，用于执行自定义例程，例如，每当发生此事件时检查删除操作的结果。
创建 DetailsViewDeleteEventHandler 委托时，需要标识将处理该事件的方法。 若要将事件与事件处理程序关联，请将该委托的一个实例添加到事件中。 除非移除了该委托，否则每当发生该事件时就会调用事件处理程序。 有关事件处理程序委托的详细信息，请参阅 处理和引发事件。
扩展方法
| GetMethodInfo(Delegate) |
获取指示指定委托表示的方法的对象。 |
