DetailsViewUpdatedEventHandler Delegát
Definice
Důležité
Některé informace platí pro předběžně vydaný produkt, který se může zásadně změnit, než ho výrobce nebo autor vydá. Microsoft neposkytuje žádné záruky, výslovné ani předpokládané, týkající se zde uváděných informací.
Představuje metodu, která zpracovává ItemUpdated událost ovládacího prvku DetailsView . Tato třída se nemůže dědit.
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)Parametry
- sender
- Object
Zdroj události
A DetailsViewUpdatedEventArgs , který obsahuje data události.
Příklady
Následující příklad kódu ukazuje, jak programově přidat DetailsViewUpdatedEventHandler delegáta ItemUpdated k události DetailsView ovládacího prvku.
<%@ 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>
Následující příklad kódu ukazuje, jak deklarativně přidat DetailsViewUpdatedEventHandler delegáta k ItemUpdated události DetailsView ovládacího prvku.
<%@ 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>
Poznámky
Ovládací DetailsView prvek vyvolá ItemUpdated událost při kliknutí na tlačítko Aktualizovat (tlačítko s jeho CommandName vlastností nastavenou na "Aktualizovat") v rámci ovládacího prvku, ale poté DetailsView , co ovládací prvek aktualizuje záznam. To vám umožní poskytnout obslužnou rutinu události, která provádí vlastní rutinu, například kontrolu výsledků operace aktualizace, kdykoli dojde k této události.
Při vytváření delegáta DetailsViewUpdatedEventHandler identifikujete metodu, která bude událost zpracovávat. Pokud chcete událost přidružit k obslužné rutině události, přidejte do události instanci delegáta. Obslužná rutina události je volána při každém výskytu události, dokud neodeberete delegáta. Další informace o delegátech obslužné rutiny událostí najdete v tématu Zpracování a vyvolávání událostí.
Metody rozšíření
| GetMethodInfo(Delegate) |
Získá objekt, který představuje metodu reprezentovanou zadaným delegátem. |
Platí pro
Viz také
Spolupracujte s námi na GitHubu
Zdroj tohoto obsahu najdete na GitHubu, kde můžete také vytvářet a kontrolovat problémy a žádosti o přijetí změn. Další informace najdete v našem průvodci pro přispěvatele.
