DetailsViewPageEventHandler Delegar
Definição
Importante
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Representa o método que manipula o PageIndexChanging evento de um DetailsView controle.
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 fonte do evento.
Um DetailsViewPageEventArgs que contém os dados do evento.
Exemplos
O exemplo de código a seguir demonstra como adicionar programaticamente um DetailsViewPageEventHandler delegado ao PageIndexChanging evento de um DetailsView controle.
<%@ 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 a seguir demonstra como adicionar declarativamente um DetailsViewPageEventHandler delegado ao PageIndexChanging evento de um DetailsView controle.
<%@ 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>
Comentários
O DetailsView controle aciona o PageIndexChanging evento quando um botão de pager (um botão com sua CommandName propriedade definida como "Página") dentro do controle é clicado, mas antes que o DetailsView controle manipule a operação de paginação. Isso permite que você forneça um manipulador de eventos que executa uma rotina personalizada, como cancelar a operação de paginação, sempre que esse evento ocorrer.
Note
Os botões de pager geralmente estão localizados na linha de pager de um DetailsView controle.
Ao criar um DetailsViewPageEventHandler delegado, você identifica o método que manipulará o evento. Para associar o evento ao manipulador de eventos, adicione uma instância do delegado ao evento. O manipulador de eventos é chamado sempre que o evento ocorre, a menos que você remova o delegado. Para obter mais informações sobre representantes do manipulador de eventos, consulte Manipulando e levantando eventos.
Métodos de Extensão
| Nome | Description |
|---|---|
| GetMethodInfo(Delegate) |
Obtém um objeto que representa o método representado pelo delegado especificado. |