DetailsViewUpdatedEventHandler Делегат
Определение
Важно!
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Представляет метод, обрабатывающий событие ItemUpdated элемента управления DetailsView. Этот класс не наследуется.
public delegate void DetailsViewUpdatedEventHandler(System::Object ^ sender, DetailsViewUpdatedEventArgs ^ e);public delegate void DetailsViewUpdatedEventHandler(object sender, DetailsViewUpdatedEventArgs e);type DetailsViewUpdatedEventHandler = delegate of obj * DetailsViewUpdatedEventArgs -> unitPublic Delegate Sub DetailsViewUpdatedEventHandler(sender As Object, e As DetailsViewUpdatedEventArgs)Параметры
- sender
- Object
Источник события.
Объект DetailsViewUpdatedEventArgs, содержащий данные события.
Примеры
В следующем примере кода показано, как программно добавить DetailsViewUpdatedEventHandler делегат в ItemUpdated событие DetailsView элемента управления .
<%@ 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.AutoGenerateEditButton = true;
customerDetailsView.AllowPaging = true;
customerDetailsView.DataKeyNames = new String[1] { "CustomerID" };
customerDetailsView.PagerSettings.Position = PagerPosition.Bottom;
// Programmatically register the event-handling methods
// for the DetailsView control.
customerDetailsView.ItemUpdated += new DetailsViewUpdatedEventHandler(this.CustomerDetailsView_ItemUpdated);
// Add the DetailsView object to the Controls collection
// of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView);
}
void CustomerDetailsView_ItemUpdated(Object sender,
DetailsViewUpdatedEventArgs e)
{
// Use the Exception property to determine whether an exception
// occurred during the insert operation.
if (e.Exception == null)
{
// Use the Values property to get the value entered by
// the user for the CompanyName field.
String keyFieldValue = e.Keys["CustomerID"].ToString();
// Display a confirmation message.
MessageLabel.Text = "Record " + keyFieldValue +
" updated successfully. ";
// Display the old and new values.
DisplayValues(e);
if (e.AffectedRows == 1)
{
MessageLabel.Text += e.AffectedRows.ToString() +
" record updated.";
}
else
{
MessageLabel.Text += e.AffectedRows.ToString() +
" records updated.";
}
}
else
{
// Insert the code to handle the exception.
MessageLabel.Text = e.Exception.Message;
// Use the ExceptionHandled property to indicate that the
// exception is already handled.
e.ExceptionHandled = true;
// When an exception occurs, keep the DetailsView
// control in edit mode.
e.KeepInEditMode = true;
}
}
void DisplayValues(DetailsViewUpdatedEventArgs e)
{
MessageLabel.Text += "<br/></br>";
// Iterate through the OldValue and NewValues
// properties and display the values.
for (int i = 0; i < e.OldValues.Count; i++)
{
MessageLabel.Text += "Old Value=" + e.OldValues[i].ToString() +
", New Value=" + e.NewValues[i].ToString() + "<br/>";
}
MessageLabel.Text += "</br>";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewUpdatedEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewUpdatedEventHandler 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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
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(sender As Object, 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.AutoGenerateEditButton = True
customerDetailsView.AllowPaging = True
customerDetailsView.PagerSettings.Position = PagerPosition.Bottom
Dim keyArray() As String = {"CustomerID"}
customerDetailsView.DataKeyNames = keyArray
' Programmatically register the event-handling methods
' for the DetailsView control.
AddHandler customerDetailsView.ItemUpdated, _
AddressOf CustomerDetailsView_ItemUpdated
' Add the DetailsView object to the Controls collection
' of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView)
End Sub
Sub CustomerDetailsView_ItemUpdated(ByVal sender As Object, _
ByVal e As DetailsViewUpdatedEventArgs)
' Use the Exception property to determine whether an exception
' occurred during the insert operation.
If e.Exception Is Nothing Then
' Use the Values property to get the value entered by
' the user for the CompanyName field.
Dim keyFieldValue As String = e.Keys("CustomerID").ToString()
' Display a confirmation message.
MessageLabel.Text = "Record " & keyFieldValue & _
" updated successfully. "
' Display the old and new values.
DisplayValues(e)
If e.AffectedRows = 1 Then
MessageLabel.Text &= e.AffectedRows.ToString() & _
" record updated."
Else
MessageLabel.Text &= e.AffectedRows.ToString() & _
" records updated."
End If
Else
' Insert the code to handle the exception.
MessageLabel.Text = e.Exception.Message
' Use the ExceptionHandled property to indicate that the
' exception is already handled.
e.ExceptionHandled = True
' When an exception occurs, keep the DetailsView
' control in edit mode.
e.KeepInEditMode = True
End If
End Sub
Sub DisplayValues(ByVal e As DetailsViewUpdatedEventArgs)
MessageLabel.Text &= "<br/></br>"
' Iterate through the OldValue and NewValues
' properties and display the values.
Dim i As Integer
For i = 0 To e.OldValues.Count - 1
MessageLabel.Text &= "Old Value=" & e.OldValues(i).ToString() & _
", New Value=" & e.NewValues(i).ToString() & "<br/>"
Next
MessageLabel.Text &= "</br>"
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewUpdatedEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewUpdatedEventHandler 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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
В следующем примере кода показано, как декларативно добавить DetailsViewUpdatedEventHandler делегат в ItemUpdated событие DetailsView элемента управления .
<%@ 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_ItemUpdated(Object sender,
DetailsViewUpdatedEventArgs e)
{
// Use the Exception property to determine whether an exception
// occurred during the insert operation.
if (e.Exception == null)
{
// Use the Values property to get the value entered by
// the user for the CompanyName field.
String keyFieldValue = e.Keys["CustomerID"].ToString();
// Display a confirmation message.
MessageLabel.Text = "Record " + keyFieldValue +
" updated successfully. ";
// Display the old and new values.
DisplayValues(e);
if (e.AffectedRows == 1)
{
MessageLabel.Text += e.AffectedRows.ToString() +
" record updated.";
}
else
{
MessageLabel.Text += e.AffectedRows.ToString() +
" records updated.";
}
}
else
{
// Insert the code to handle the exception.
MessageLabel.Text = e.Exception.Message;
// Use the ExceptionHandled property to indicate that the
// exception is already handled.
e.ExceptionHandled = true;
// When an exception occurs, keep the DetailsView
// control in edit mode.
e.KeepInEditMode = true;
}
}
void DisplayValues(DetailsViewUpdatedEventArgs e)
{
MessageLabel.Text += "<br/></br>";
// Iterate through the OldValue and NewValues
// properties and display the values.
for (int i = 0; i < e.OldValues.Count; i++)
{
MessageLabel.Text += "Old Value=" + e.OldValues[i].ToString() +
", New Value=" + e.NewValues[i].ToString() + "<br/>";
}
MessageLabel.Text += "</br>";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewUpdatedEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewUpdatedEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogenerateeditbutton="true"
allowpaging="true"
datakeynames="CustomerID"
onitemupdated="CustomerDetailsView_ItemUpdated"
runat="server">
<pagersettings position="Bottom"/>
</asp:detailsview>
<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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
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_ItemUpdated(ByVal sender As Object, ByVal e As DetailsViewUpdatedEventArgs) Handles CustomerDetailsView.ItemUpdated
' Use the Exception property to determine whether an exception
' occurred during the insert operation.
If e.Exception Is Nothing Then
' Use the Values property to get the value entered by
' the user for the CompanyName field.
Dim keyFieldValue As String = e.Keys("CustomerID").ToString()
' Display a confirmation message.
MessageLabel.Text = "Record " & keyFieldValue & _
" updated successfully. "
' Display the old and new values.
DisplayValues(e)
If e.AffectedRows = 1 Then
MessageLabel.Text &= e.AffectedRows.ToString() & _
" record updated."
Else
MessageLabel.Text &= e.AffectedRows.ToString() & _
" records updated."
End If
Else
' Insert the code to handle the exception.
MessageLabel.Text = e.Exception.Message
' Use the ExceptionHandled property to indicate that the
' exception is already handled.
e.ExceptionHandled = True
' When an exception occurs, keep the DetailsView
' control in edit mode.
e.KeepInEditMode = True
End If
End Sub
Sub DisplayValues(ByVal e As DetailsViewUpdatedEventArgs)
MessageLabel.Text &= "<br/></br>"
' Iterate through the OldValue and NewValues
' properties and display the values.
Dim i As Integer
For i = 0 To e.OldValues.Count - 1
MessageLabel.Text &= "Old Value=" & e.OldValues(i).ToString() & _
", New Value=" & e.NewValues(i).ToString() & "<br/>"
Next
MessageLabel.Text &= "</br>"
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewUpdatedEvent Handler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewUpdatedEvent Handler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogenerateeditbutton="true"
allowpaging="true"
datakeynames="CustomerID"
runat="server">
<pagersettings position="Bottom"/>
</asp:detailsview>
<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]"
updatecommand="Update [Customers] Set
[CompanyName]=@CompanyName, [Address]=@Address,
[City]=@City, [PostalCode]=@PostalCode,
[Country]=@Country
Where [CustomerID]=@CustomerID"
connectionstring=
"<%$ ConnectionStrings:NorthWindConnectionString%>"
runat="server"/>
</form>
</body>
</html>
Комментарии
Элемент DetailsView управления вызывает ItemUpdated событие при нажатии кнопки Обновить (кнопка со свойством CommandName "Обновить") в элементе управления, но после DetailsView обновления записи элементом управления. Это позволяет предоставить обработчик событий, который выполняет пользовательскую подпрограмму, например проверку результатов операции обновления при каждом возникновении этого события.
При создании делегата DetailsViewUpdatedEventHandler необходимо указать метод, обрабатывающий событие. Чтобы связать событие с обработчиком событий, нужно добавить в событие экземпляр делегата. Обработчик событий вызывается всякий раз, когда происходит событие, если делегат не удален. Дополнительные сведения о делегатах обработчика событий см. в разделе Обработка и вызов событий.
Методы расширения
| GetMethodInfo(Delegate) |
Получает объект, представляющий метод, представленный указанным делегатом. |
Применяется к
См. также раздел
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