TextBox.OnPreRender(EventArgs) 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
如果 AutoPostBack 是 true
,则在客户端上呈现之前注册用于生成回发事件的客户端脚本。
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)
参数
示例
下面的代码示例演示如何重写 方法, OnPreRender 使其始终在自定义 TextBox 服务器控件中显示一个点边框。
重要
此示例具有一个接受用户输入的文本框,这是一个潜在的安全威胁。 默认情况下,ASP.NET 网页验证用户输入是否不包含脚本或 HTML 元素。 有关详细信息,请参阅脚本侵入概述。
<%@ 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 TextBox - OnPreRender - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom TextBox - OnPreRender - C# Example</h3>
<aspSample:CustomTextBoxOnPreRender
id="TextBox1"
runat="server">Hello World!
</aspSample:CustomTextBoxOnPreRender>
</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 TextBox - OnPreRender - VB.NET Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom TextBox - OnPreRender - VB.NET Example</h3>
<aspSample:CustomTextBoxOnPreRender id="TextBox1"
runat="server">Hello World!</aspSample:CustomTextBoxOnPreRender>
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomTextBoxOnPreRender : System.Web.UI.WebControls.TextBox
{
protected override void OnPreRender(System.EventArgs e)
{
// Run the OnPreRender method on the base class.
base.OnPreRender(e);
// Display the TextBox with a 1 point border.
this.BorderWidth = System.Web.UI.WebControls.Unit.Point(1);
}
}
}
Imports System.Web
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomTextBoxOnPreRender
Inherits System.Web.UI.WebControls.TextBox
Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
' Run the OnPreRender method on the base class.
MyBase.OnPreRender(e)
' Display the TextBox with a 1 point border.
Me.BorderWidth = System.Web.UI.WebControls.Unit.Point(1)
End Sub
End Class
End Namespace