LinkButton.OnPreRender(EventArgs) 方法
定义
重要
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引发 PreRender 事件。
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 -> unitProtected Overrides Sub OnPreRender (e As EventArgs)Protected Friend Overrides Sub OnPreRender (e As EventArgs)参数
示例
下面的代码示例演示如何重写 方法， OnPreRender 使边框永远不会显示在自定义 LinkButton 控件中。
<%@ 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
注解
方法 OnPreRender 通知 控件在 LinkButton 保存视图状态并将内容呈现到客户端之前执行任何必要的预呈现步骤。
