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 OnPreRender 该方法,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