ImageButton.AddAttributesToRender(HtmlTextWriter) 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。
将 ImageButton 的特性添加到输出流以备在客户端呈现。
protected:
override void AddAttributesToRender(System::Web::UI::HtmlTextWriter ^ writer);protected override void AddAttributesToRender (System.Web.UI.HtmlTextWriter writer);override this.AddAttributesToRender : System.Web.UI.HtmlTextWriter -> unitProtected Overrides Sub AddAttributesToRender (writer As HtmlTextWriter)参数
- writer
- HtmlTextWriter
要在客户端呈现的输出流。
示例
下面的代码示例演示如何重写 AddAttributesToRender 自定义服务器控件中的方法，以便 ImageButton 文本始终以精简边框显示。
备注
下面的代码示例使用单文件代码模型，如果直接复制到代码隐藏文件中，可能无法正常工作。 此代码示例的第一部分必须复制到扩展名为 .aspx 的空文本文件中。 第二部分必须另存为代码文件， (.cs for C# 或 .vb for Visual Basic) 。 有关Web Forms代码模型的详细信息，请参阅 ASP.NET Web Forms页代码模型。
<%@ 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 ImageButton - AddAttributesToRender - C# Example</title>
<script runat="server">
void ImageButton1_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 ImageButton - AddAttributesToRender - C# Example</h3>
<aspSample:CustomImageButtonAddAttributesToRender id="ImageButton1" runat="server"
OnCommand="ImageButton1_Command" AlternateText="Microsoft Home"
ImageUrl="http://www.microsoft.com/homepage/gif/bnr-microsoft.gif" />
</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 ImageButton - AddAttributesToRender - VB.NET Example</title>
<script runat="server">
Sub ImageButton1_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 ImageButton - AddAttributesToRender - VB.NET Example</h3>
<aspSample:CustomImageButtonAddAttributesToRender id="ImageButton1" runat="server"
OnCommand="ImageButton1_Command" AlternateText="Microsoft Home"
ImageUrl="http://www.microsoft.com/homepage/gif/bnr-microsoft.gif" />
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomImageButtonAddAttributesToRender : System.Web.UI.WebControls.ImageButton
{
protected override void AddAttributesToRender(System.Web.UI.HtmlTextWriter writer)
{
// Show the ImageButton with a thin border.
writer.AddStyleAttribute("border-width","thin");
// Call the Base's AddAttributesToRender method.
base.AddAttributesToRender(writer);
}
}
}
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomImageButtonAddAttributesToRender
Inherits System.Web.UI.WebControls.ImageButton
Protected Overrides Sub AddAttributesToRender(ByVal writer As System.Web.UI.HtmlTextWriter)
' Show the ImageButton with a thin border.
writer.AddStyleAttribute("border-width", "thin")
' Call the Base's AddAttributesToRender method.
MyBase.AddAttributesToRender(writer)
End Sub
End Class
注解
从控件派生自定义类ImageButton时，该方法OnPreRender主要由控件开发人员使用。