HtmlInputButton.OnPreRender(EventArgs) 方法
定义
引发 OnPreRender(EventArgs) 事件并为生成回发而注册客户端脚本。Raises the OnPreRender(EventArgs) event and registers client script for generating postback.
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 方法,以便它始终显示 HtmlInputButton 带有粗体文本的自定义控件。The following code example demonstrates how to override the OnPreRender method so that it always displays a custom HtmlInputButton control with bold text.
<%@ 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 HtmlInputButton - OnPreRender - C# Example</title>
<script runat="server">
void Page_Load(Object sender, EventArgs e)
{
HtmlInputButton1.Attributes.Add("onclick","alert('Hello client-side world.');");
}
void HtmlInputButton1_ServerClick(Object sender, EventArgs e)
{
Div1.InnerHtml = "Hello server-side world.";
}
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlInputButton - OnPreRender - C# Example</h3>
<aspSample:CustomHtmlInputButtonOnPreRender
id="HtmlInputButton1"
runat="server"
type="button"
onserverclick="HtmlInputButton1_ServerClick"
value="Html Input Button"
name="HtmlInputButton1">
<div id="Div1" runat="server"
style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
</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 HtmlInputButton - OnPreRender - Visual Basic Example</title>
<script runat="server">
Sub Page_Load(sender As Object, e As EventArgs)
HtmlInputButton1.Attributes.Add("onclick", "alert('Hello client-side world.');")
End Sub
Sub HtmlInputButton1_ServerClick(sender As Object, e As EventArgs)
Div1.InnerHtml = "Hello server-side world."
End Sub
</script>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlInputButton - OnPreRender - Visual Basic Example</h3>
<aspSample:CustomHtmlInputButtonOnPreRender
id="HtmlInputButton1"
runat="server"
type="button"
onserverclick="HtmlInputButton1_ServerClick"
value="Html Input Button"
name="HtmlInputButton1">
<div id="Div1" runat="server"
style="DISPLAY: inline; WIDTH: 256px; HEIGHT: 15px" />
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomHtmlInputButtonOnPreRender : System.Web.UI.HtmlControls.HtmlInputButton
{
protected override void OnPreRender(System.EventArgs e)
{
// Call the base class's OnPreRender method.
base.OnPreRender(e);
// Always display the HtmlInputButton with bold text.
this.Style.Add("font-weight", "bold");
}
}
}
Imports System.Web
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomHtmlInputButtonOnPreRender
Inherits System.Web.UI.HtmlControls.HtmlInputButton
Protected Overrides Sub OnPreRender(ByVal e As System.EventArgs)
' Call the base class's OnPreRender method.
MyBase.OnPreRender(e)
' Always display the HtmlInputButton with bold text.
Me.Style.Add("font-weight", "bold")
End Sub
End Class
End Namespace
注解
OnPreRender方法将重写 Control.OnPreRender 方法。The OnPreRender method overrides the Control.OnPreRender method. OnPreRender 主要由控件开发人员使用。OnPreRender is used primarily by control developers.