ImageButton.AddAttributesToRender Method (HtmlTextWriter)

 

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 Overrides Sub AddAttributesToRender (
	writer As HtmlTextWriter
)

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.

System_CAPS_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.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>
<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

.NET Framework
Available since 1.1
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