Image.RenderContents(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。
将图像控件内容呈现到指定的编写器。
protected:
override void RenderContents(System::Web::UI::HtmlTextWriter ^ writer);protected public:
override void RenderContents(System::Web::UI::HtmlTextWriter ^ writer);protected override void RenderContents (System.Web.UI.HtmlTextWriter writer);protected internal override void RenderContents (System.Web.UI.HtmlTextWriter writer);override this.RenderContents : System.Web.UI.HtmlTextWriter -> unitProtected Overrides Sub RenderContents (writer As HtmlTextWriter)Protected Friend Overrides Sub RenderContents (writer As HtmlTextWriter)参数
- writer
- HtmlTextWriter
表示在客户端上呈现 HTML 内容的输出流的 HtmlTextWriter。
示例
下面的代码示例演示如何重写 RenderContents 自定义服务器控件中的方法，以便某些文本始终显示在之后 Image。
<%@ 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 Image - RenderContents - C# Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom Image - RenderContents - C# Example</h3>
<aspSample:CustomImageRenderContents
id="Image1"
runat="server"
ImageUrl="http://www.microsoft.com/homepage/gif/bnr-microsoft.gif"
AlternateText="Microsoft Home" />
</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 Image - RenderContents - VB.NET Example</title>
</head>
<body>
<form id="Form1" method="post" runat="server">
<h3>Custom Image - RenderContents - VB.NET Example</h3>
<aspSample:CustomImageRenderContents id="Image1" runat="server"
ImageUrl="http://www.microsoft.com/homepage/gif/bnr-microsoft.gif"
AlternateText="Microsoft Home" />
</form>
</body>
</html>
using System.Web;
using System.Security.Permissions;
namespace Samples.AspNet.CS.Controls
{
[AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
public sealed class CustomImageRenderContents : System.Web.UI.WebControls.Image
{
protected override void RenderContents(System.Web.UI.HtmlTextWriter writer)
{
// Call the base RenderContents method.
base.RenderContents(writer);
// Append some text to the Image.
writer.Write("<BR>Experience Windows Server 2003 and Visual Studio® .NET 2003.");
}
}
}
<AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class CustomImageRenderContents
Inherits System.Web.UI.WebControls.Image
Protected Overrides Sub RenderContents(ByVal writer As System.Web.UI.HtmlTextWriter)
' Call the base RenderContents method.
MyBase.RenderContents(writer)
' Append some text to the Image.
writer.Write("<BR>Experience Windows Server 2003 and Visual Studio .NET 2003.")
End Sub
End Class
注解
该方法 RenderContents 主要由控件开发人员使用。 该 Image 控件实现 RenderContents 方法以跳过任何子控件的呈现。