1. 添加CSS样式: Style style = new Style();

style.ForeColor = System.Drawing.Color.Navy;

style.BackColor = System.Drawing.Color.LightGray;

this.Header.StyleSheet.CreateStyleRule(style, null, "body");

2. 链接外部的CSS样式表: HtmlLink link = new HtmlLink();

link.Attributes.Add("type", "text/css");

link.Attributes.Add("rel", "stylesheet");

link.Attributes.Add("href", "~/newstyle.css");

this.Header.Controls.Add(link);

方法3 aa.aspx.cs public string m_StyleSrc = string.Empty; //公共变量 ,样式文件路径

private void Page_Load(object sender, System.EventArgs e) {

m_StyleSrc = "../xxx.css"; //页面加载时赋值 }

}

aa.aspx <LINK href="<%=m_StyleSrc%>" type="text/css" rel="stylesheet">

方法4 下面这个方法没试过,不知是否能用

protected void Page_Onload(object sender, EventArgs e) {

Page.StyleSheetTheme = "../css/infomore.css";

}

方法5 页面：

<link href="" rel="stylesheet" type="text/css" id="css" runat="server"/>

后台

this.css.Href = "css文件路径";