.aspx.cs
using System.Web.UI.HtmlControls;
public partial class _Default: System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
HtmlInputCheckBox chk = new HtmlInputCheckBox();
chk.ID = "chk1";
chk.Value = "1";
chk.Checked = true;
Panel1.Controls.Add(chk);
}
}
.aspx