HtmlImage.RenderAttributes(HtmlTextWriter) Method
Definition
Important
Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.
Renders the HtmlImage control's attributes to the specified HtmlTextWriter object.
protected:
override void RenderAttributes(System::Web::UI::HtmlTextWriter ^ writer);
protected override void RenderAttributes (System.Web.UI.HtmlTextWriter writer);
override this.RenderAttributes : System.Web.UI.HtmlTextWriter -> unit
Protected Overrides Sub RenderAttributes (writer As HtmlTextWriter)
Parameters
- writer
- HtmlTextWriter
The HtmlTextWriter that contains the output stream to render on the client.
Exceptions
The Src property contains a malformed URL.
Examples
The following code example demonstrates how to override the RenderAttributes method in a custom server control so that specific alternative text, accessible as a ToolTip, is always displayed with the HtmlImage control.
<%@ 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 HtmlImage - RenderAttributes - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlImage - RenderAttributes - C# Example</h3>
<aspSample:CustomHtmlImageRenderAttributes id="Img1"
runat="server"
border="0"
src="image.jpg" />
</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 HtmlImage - RenderAttributes - Visual Basic Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom HtmlImage - RenderAttributes - Visual Basic Example</h3>
<aspSample:CustomHtmlImageRenderAttributes id="Img1"
runat="server"
border="0"
src="image.jpg" />
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomHtmlImageRenderAttributes : System.Web.UI.HtmlControls.HtmlImage
{
protected override void RenderAttributes(System.Web.UI.HtmlTextWriter writer)
{
// Call the base class's RenderAttributes method.
base.RenderAttributes(writer);
// Write out the HtmlImage control's alt tag.
writer.Write(" alt=\"Text from custom RenderAttributes method.\"");
}
}
}
Imports System.Web
Imports System.Security.Permissions
Namespace Samples.AspNet.VB.Controls
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomHtmlImageRenderAttributes
Inherits System.Web.UI.HtmlControls.HtmlImage
Protected Overrides Sub RenderAttributes(ByVal writer As System.Web.UI.HtmlTextWriter)
' Call the base class's RenderAttributes method.
MyBase.RenderAttributes(writer)
' Write out the HtmlImage control's alt tag.
writer.Write(" alt=""Text from custom RenderAttributes method.""")
End Sub
End Class
End Namespace
Remarks
If the value of the Src property is a malformed URL, the RenderAttributes method throws an HttpException exception.
The RenderAttributes method overrides the base class's RenderAttributes method to write the src
attribute of the rendered HtmlImage control.
The RenderAttributes method is used primarily by control developers extending the functionality of the HtmlImage control.
Applies to
See also
.NET
피드백
https://aka.ms/ContentUserFeedback
출시 예정: 2024년 내내 콘텐츠에 대한 피드백 메커니즘으로 GitHub 문제를 단계적으로 폐지하고 이를 새로운 피드백 시스템으로 바꿀 예정입니다. 자세한 내용은 다음을 참조하세요.다음에 대한 사용자 의견 제출 및 보기