DetailsViewPageEventHandler Delegar
Definição
Importante
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Representa o método que gere o PageIndexChanging evento de um DetailsView controlo.
public delegate void DetailsViewPageEventHandler(System::Object ^ sender, DetailsViewPageEventArgs ^ e);public delegate void DetailsViewPageEventHandler(object sender, DetailsViewPageEventArgs e);type DetailsViewPageEventHandler = delegate of obj * DetailsViewPageEventArgs -> unitPublic Delegate Sub DetailsViewPageEventHandler(sender As Object, e As DetailsViewPageEventArgs)Parâmetros
- sender
- Object
A origem do evento.
A DetailsViewPageEventArgs que contém os dados do evento.
Exemplos
O exemplo de código seguinte demonstra como adicionar programaticamente um DetailsViewPageEventHandler delegado ao PageIndexChanging evento de um DetailsView controlo.
<%@ 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.PageIndexChanging += new DetailsViewPageEventHandler(this.CustomerDetailsView_PageIndexChanging);
customerDetailsView.ModeChanging += new DetailsViewModeEventHandler(this.CustomerDetailsView_ModeChanging);
// Add the DetailsView object to the Controls collection
// of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView);
}
void CustomerDetailsView_PageIndexChanging(Object sender, DetailsViewPageEventArgs e)
{
// Use the sender parameter to access the DetailsView control
// that raised the event.
DetailsView customerDetailsView = (DetailsView)sender;
// Cancel the paging operation if the DetailsView control
// in edit mode.
if (customerDetailsView.CurrentMode == DetailsViewMode.Edit)
{
e.Cancel = true;
// Display an error message.
int newPage = e.NewPageIndex + 1;
MessageLabel.Text = "Please update the current record before to moving to page " +
newPage.ToString() + ".";
}
}
void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
{
// Clear the message label when the user changes mode.
MessageLabel.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler 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(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.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.PageIndexChanging, AddressOf CustomerDetailsView_PageIndexChanging
AddHandler customerDetailsView.ModeChanging, AddressOf CustomerDetailsView_ModeChanging
' Add the DetailsView object to the Controls collection
' of the PlaceHolder control.
DetailsViewPlaceHolder.Controls.Add(customerDetailsView)
End Sub
Sub CustomerDetailsView_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs)
' Use the sender parameter to access the DetailsView control
' that raised the event.
Dim customerDetailsView As DetailsView = CType(sender, DetailsView)
' Cancel the paging operation if the DetailsView control
' in edit mode.
If customerDetailsView.CurrentMode = DetailsViewMode.Edit Then
e.Cancel = True
' Display an error message.
Dim newPage As Integer = e.NewPageIndex + 1
MessageLabel.Text = "Please update the current record before to moving to page " & _
newPage.ToString() & "."
End If
End Sub
Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs)
' Clear the message label when the user changes mode.
MessageLabel.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler 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>
O exemplo de código seguinte demonstra como adicionar declarativamente um DetailsViewPageEventHandler delegado ao PageIndexChanging evento de um DetailsView controlo.
<%@ 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_PageIndexChanging(Object sender, DetailsViewPageEventArgs e)
{
// Cancel the paging operation if the DetailsView control
// in edit mode.
if (CustomerDetailsView.CurrentMode == DetailsViewMode.Edit)
{
e.Cancel = true;
// Display an error message.
int newPage = e.NewPageIndex + 1;
MessageLabel.Text = "Please update the current record before to moving to page " +
newPage.ToString() + ".";
}
}
void CustomerDetailsView_ModeChanging(Object sender, DetailsViewModeEventArgs e)
{
// Clear the message label when the user changes mode.
MessageLabel.Text = "";
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogenerateeditbutton="true"
datakeynames="CustomerID"
allowpaging="true"
onpageindexchanging="CustomerDetailsView_PageIndexChanging"
onmodechanging="CustomerDetailsView_ModeChanging"
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" %>
<!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_PageIndexChanging(ByVal sender As Object, ByVal e As DetailsViewPageEventArgs) Handles CustomerDetailsView.PageIndexChanging
' Cancel the paging operation if the DetailsView control
' in edit mode.
If CustomerDetailsView.CurrentMode = DetailsViewMode.Edit Then
e.Cancel = True
' Display an error message.
Dim newPage As Integer = e.NewPageIndex + 1
MessageLabel.Text = "Please update the current record before to moving to page " & _
newPage.ToString() & "."
End If
End Sub
Sub CustomerDetailsView_ModeChanging(ByVal sender As Object, ByVal e As DetailsViewModeEventArgs) Handles CustomerDetailsView.ModeChanging
' Clear the message label when the user changes mode.
MessageLabel.Text = ""
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>DetailsViewPageEventHandler Example</title>
</head>
<body>
<form id="form1" runat="server">
<h3>DetailsViewPageEventHandler Example</h3>
<asp:detailsview id="CustomerDetailsView"
datasourceid="DetailsViewSource"
autogeneraterows="true"
autogenerateeditbutton="true"
datakeynames="CustomerID"
allowpaging="true"
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>
Observações
O DetailsView controlo levanta o PageIndexChanging evento quando um botão do pager (um botão com CommandName a propriedade definida como "Página") dentro do controlo é clicado, mas antes do controlo DetailsView tratar da operação de paginação. Isto permite-lhe fornecer um gestor de eventos que executa uma rotina personalizada, como cancelar a operação de paginação, sempre que este evento ocorre.
Note
Os botões de pager estão normalmente localizados na linha de pagers de um DetailsView controlo.
Quando cria um DetailsViewPageEventHandler delegado, identifica o método que irá gerir o evento. Para associar o evento ao seu gestor de eventos, adicione uma instância do delegado ao evento. O gestor de eventos é chamado sempre que o evento ocorre, a menos que remova o delegado. Para mais informações sobre os delegados handlers de eventos, consulte Gestão e Angariação de Eventos.
Métodos da Extensão
| Name | Description |
|---|---|
| GetMethodInfo(Delegate) |
Obtém um objeto que representa o método representado pelo delegado especificado. |