自定义复合控件[5]获取包含的文本

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;

namespace csMathControl
{
/// <summary>
/// Center 的摘要说明。
/// </summary>
[DefaultProperty("Text"),
ToolboxData("<{0}:Center runat=server></{0}:Center>")]
[ParseChildren(false)]
public class Center : System.Web.UI.WebControls.WebControl,INamingContainer
{
private string text;

[Bindable(true),
Category("Appearance"),
DefaultValue("")]
public string Text
{
get
{
return text;
}

set
{
text = value;
}
}

/// <summary>
/// 将此控件呈现给指定的输出参数。
/// </summary>
/// <param name="output"> 要写出到的 HTML 编写器 </param>
protected override void Render(HtmlTextWriter output)
{
//output.Write(Text);
output.AddAttribute("align","center");
output.AddStyleAttribute("BackGround-color","red");
//pannel开始
output.RenderBeginTag("div");
foreach(Control ctrItem in Controls)
{
ctrItem.RenderControl(output);
}
output.RenderEndTag();
}
}
}