// Render: <meta name="keywords" content="Some words listed here" />
HtmlMeta meta = new HtmlMeta();
meta.Name = "keywords";
meta.Content = "Some words listed here";
this.Header.Controls.Add(meta);

// Render: <meta name="robots" content="noindex" />
meta = new HtmlMeta();
meta.Name = "robots";
meta.Content = "noindex";
this.Header.Controls.Add(meta);

// Render: <meta name="date" content="2006-03-25" scheme="YYYY-MM-DD" />
meta = new HtmlMeta();
meta.Name = "date";
meta.Content = DateTime.Now.ToString("yyyy-MM-dd");
meta.Scheme = "YYYY-MM-DD";
this.Header.Controls.Add(meta);

------解决方案--------------------
我是写在masterpage里，不同的页，赋值Session("currentpage"),根据库里的不同页不同关键词填充。
  Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
       makemeta(Session("currentpage"))
   End Sub
   Sub makemeta(ByVal item As String)
       Dim ds As DataSet = toolClass.getmeta(item)
       Page.Title = ds.Tables(0).Rows(0)("title")
       Dim meta As New HtmlMeta
       meta.Name = "keywords"
       meta.Content = ds.Tables(0).Rows(0)("keywords")
       Page.Header.Controls.Add(meta)
       meta.Name = "description"
       meta.Content = ds.Tables(0).Rows(0)("description")
       Page.Header.Controls.Add(meta)
   End Sub

------解决方案--------------------
C# code
public class initfunc : System.Web.UI.Page
{
public initfunc()
{
//
// TODO: 在此处添加构造函数逻辑
//
}
     public void setMeta(System.Web.UI.Control page,string key, string des)
     {
        HtmlMeta keywords = new HtmlMeta(), description = new HtmlMeta(); // keywords, description
        keywords.Name = "keywords";
        keywords.Content = key;

        description.Name = "description";
        description.Content = des;

        page.Header.Controls.Add(keywords);
        page.Header.Controls.Add(description);
    }
} 
//加个参数，使用的时候
initfunc ini = new initfunc();
protected void Page_Load(object sender, EventArgs e)
{
    ini.setMeta(this,"1111", "2222");
}

------解决方案--------------------

C# code


    public class AA
    { 
        public static void setMeta(string keyWords)
        {
            System.Web.UI.HtmlControls.HtmlMeta m = new HtmlMeta();
            m.Name = "keywords";
            m.Content =