AttributeCollection.Render(HtmlTextWriter) 方法
定义
重要
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将特性集合写入该集合所属的控件的指定 HtmlTextWriter 输出流。
public:
void Render(System::Web::UI::HtmlTextWriter ^ writer);public void Render (System.Web.UI.HtmlTextWriter writer);member this.Render : System.Web.UI.HtmlTextWriter -> unitPublic Sub Render (writer As HtmlTextWriter)参数
- writer
- HtmlTextWriter
将特性集合写入当前输出流的 HtmlTextWriter 实例。
示例
本部分包含两个代码示例。 第一个代码示例演示如何从 WebControl 类继承，以创建一个名为 AttribRender 替代该方法的 Render 自定义控件。 第二个代码示例演示如何在 ASP.NET 网页中使用自定义控件。
以下示例演示如何创建一 AttribRender 个名为替代 Render 类方法的 WebControl 自定义控件，而无需调用 Render 基类的方法。 AttribRender而是调用Render该方法。
/* Create a custom WebControl class, named AttribRender, that overrides
the Render method to write two introductory strings. Then call the
AttributeCollection.Render method, which allows the control to write the
attribute values that are added to it when it is included in a page.
*/
using System;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Security.Permissions;
// Create the namespace that contains the AttribRender and the
// page that accesses it.
namespace AC_Render
{
// This is the custom WebControl class.
[AspNetHostingPermission(SecurityAction.Demand,
Level=AspNetHostingPermissionLevel.Minimal)]
public class AttribRender : WebControl
{
// This is the overridden WebControl.Render method.
protected override void Render(HtmlTextWriter output)
{
output.Write("<h2>An AttributeCollection.Render Method Example</h2>");
output.Write("The attributes, and their values, added to the ctl1 control are <br><br>");
// This is the AttributeCollection.Render method call. When the
// page that contains this control is requested, the
// attributes that the page adds, and their values,
// are rendered to the page.
Attributes.Render(output);
}
}
}
' Create a custom WebControl class, named AttribRender, that overrides
' the Render method to write two introductory strings. Then call the
' AttributeCollection.Render method, which allows the control to write the
' attribute values that are added to it when it is included in a page.
Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Security.Permissions
' Create the namespace that contains the AttribRender and the
' page that accesses it.
Namespace AC_Render
' This is the custom WebControl class.
<AspNetHostingPermission(SecurityAction.Demand, _
Level:=AspNetHostingPermissionLevel.Minimal)> _
Public Class AttribRender
Inherits WebControl
' This is the overridden WebControl.Render method.
Protected Overrides Sub Render(ByVal output As HtmlTextWriter)
output.Write("<h2>An AttributeCollection.Render Method Example</h2>")
output.Write("The attributes, and their values, added to the ctl1 control are <br><br>")
' This is the AttributeCollection.Render method call. When the
' page that contains this control is requested, the
' attributes that the page adds, and their values,
' are rendered to the page.
Attributes.Render(output)
End Sub
End Class
End Namespace 'AC_Render
以下示例演示如何在网页中使用 AttribRender 自定义控件。 它假定自定义控件的代码文件位于应用程序的App_Code文件夹中。
<%@ Page Language="C#"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
AC_Render.AttribRender c = new AC_Render.AttribRender();
c.Attributes.Add("Text", "Hello World!");
c.Attributes.Add("Attribute1", "The value for Attribute1.");
Place1.Controls.Add(c);
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>AttributeCollection Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:PlaceHolder id="Place1" runat="server"></asp:PlaceHolder>
</div>
</form>
</body>
</html>
<%@ Page Language="VB"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
Dim c As New AC_Render.AttribRender()
c.Attributes.Add("Text", "Hello World!")
c.Attributes.Add("Attribute1", "The value for Attribute1.")
Place1.Controls.Add(c)
End Sub
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>AttributeCollection Example</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:PlaceHolder id="Place1" runat="server"></asp:PlaceHolder>
</div>
</form>
</body>
</html>