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ImageButton.AddAttributesToRender Method

Adds the attributes of an ImageButton to the output stream for rendering on the client.

Namespace:  System.Web.UI.WebControls
Assembly:  System.Web (in System.Web.dll)

protected override void AddAttributesToRender(
	HtmlTextWriter writer
)

Parameters

writer
Type: System.Web.UI.HtmlTextWriter

The output stream to render on the client.

The OnPreRender method is used primarily by control developers when deriving a custom class from the ImageButton control.

The following code example demonstrates how to override the AddAttributesToRender method in a custom server control so that the ImageButton text always appears with a thin border.

NoteNote

The following code sample uses the single-file code model and may not work correctly if copied directly into a code-behind file. The first part of this code sample must be copied into an empty text file that has an .aspx extension. The second part must be saved as a code file (either .cs for C# or .vb for Visual Basic). For more information on the Web Forms code model, see ASP.NET Web Forms Page Code Model.

<%@ 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>


...


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);
        }
    }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1
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