LinkButton.OnPreRender(EventArgs) Método
Definição
Importante
Algumas informações se referem a produtos de pré-lançamento que podem ser substancialmente modificados antes do lançamento. A Microsoft não oferece garantias, expressas ou implícitas, das informações aqui fornecidas.
Aciona o evento PreRender.
protected:
override void OnPreRender(EventArgs ^ e);
protected public:
override void OnPreRender(EventArgs ^ e);
protected override void OnPreRender (EventArgs e);
protected internal override void OnPreRender (EventArgs e);
override this.OnPreRender : EventArgs -> unit
Protected Overrides Sub OnPreRender (e As EventArgs)
Protected Friend Overrides Sub OnPreRender (e As EventArgs)
Parâmetros
Exemplos
O exemplo de código a seguir demonstra como substituir o OnPreRender método para que uma borda nunca seja exibida em um controle personalizado LinkButton .
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.CS.Controls" Assembly="Samples.AspNet.CS" %>
<%@ Page Language="C#" AutoEventWireup="True" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Custom LinkButton - OnPreRender - C# Example</title>
<script runat="server">
void LinkButton1_Command(Object sender, CommandEventArgs e)
{
// Redirect to the Microsoft home page.
Response.Redirect("http://www.microsoft.com/");
}
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom LinkButton - OnPreRender - C# Example</h3>
<aspSample:CustomLinkButtonOnPreRender
id="LinkButton1"
runat="server"
OnCommand="LinkButton1_Command"
ToolTip="Microsoft Home">Microsoft Corp.
</aspSample:CustomLinkButtonOnPreRender>
</form>
</body>
</html>
<%@ Register TagPrefix="aspSample" Namespace="Samples.AspNet.VB.Controls" Assembly="Samples.AspNet.VB" %>
<%@ Page Language="VB" AutoEventWireup="True" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>Custom LinkButton - OnPreRender - VB.NET Example</title>
<script runat="server">
Sub LinkButton1_Command(sender As Object, e As CommandEventArgs)
' Redirect to the Microsoft home page.
Response.Redirect("http://www.microsoft.com/")
End Sub
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom LinkButton - OnPreRender - VB.NET Example</h3>
<aspSample:CustomLinkButtonOnPreRender id="LinkButton1"
runat="server" OnCommand="LinkButton1_Command"
ToolTip="Microsoft Home">Microsoft Corp.</aspSample:CustomLinkButtonOnPreRender>
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomLinkButtonOnPreRender : System.Web.UI.WebControls.LinkButton
{
protected override void OnPreRender(System.EventArgs e)
{
// Run the OnPreRender method on the base class.
base.OnPreRender(e);
// Always display the LinkButton without a border.
this.BorderWidth = System.Web.UI.WebControls.Unit.Point(0);
}
}
}
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomLinkButtonOnPreRender
Inherits System.Web.UI.WebControls.LinkButton
Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
' Run the OnPreRender method on the base class.
MyBase.OnPreRender(e)
' Always display the LinkButton without a border.
Me.BorderWidth = System.Web.UI.WebControls.Unit.Point(0)
End Sub
End Class
Comentários
O OnPreRender método notifica o LinkButton controle para executar as etapas de pré-geração necessárias antes de salvar o estado do modo de exibição e renderizar o conteúdo para o cliente.