ImageButton.AddAttributesToRender(HtmlTextWriter) 方法

定义

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 -> unit
Protected 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在自定义服务器控件中重写 AddAttributesToRender 方法,以便 ImageButton 文本始终以细边框显示。

注意

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。 必须将此代码示例的第一部分复制到扩展名为 .aspx 的空文本文件中。 第二部分必须保存为代码文件, (C# .cs或 Visual Basic) .vb。 有关 Web 窗体代码模型的详细信息,请参阅 ASP.NET Web 窗体页代码模型

<%@ 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

OnPreRender 控件派生自定义类 ImageButton 时,控件开发人员主要使用 方法。

适用于

另请参阅