protected override void Render(HtmlTextWriter writer)
{
//把最终要输出的html压缩后再输出
StringWriter html = new StringWriter();
HtmlTextWriter tw = new HtmlTextWriter(html);
base.Render(tw);
string outhtml = html.ToString();
outhtml = Regex.Replace(outhtml, "\\s+", " ");
outhtml = Regex.Replace(outhtml, ">\\s+<", "><");
outhtml = outhtml.Trim();
writer.Write(outhtml);
}

protected override void Render(HtmlTextWriter writer)
{
//最终输出前先存为html文件，如果发布最新信息了，可以打开一次default.aspx,然后他又会生成一次html

//这是默认的Render实现，直接输出到writer中
//base.Render(writer);
StringWriter html = new StringWriter();
HtmlTextWriter tw = new HtmlTextWriter(html);
//通过base.Render()方法，把生成的HTML写入到我们定义的tw中
base.Render(tw);
string path = Server.MapPath("index.html");
StreamWriter sw = new StreamWriter(path, false, System.Text.Encoding.Default);
//写入到文件中
sw.Write(html.ToString());
sw.Close();
//写入到writer中，以输出页面的HTML
//注意，这里不能再调用base.Render(writer)，会出现错误
writer.Write(html.ToString());
}