开发PDA的程序时发生错误"路径无效。请检查数据库的目录。"

Question

在本机上用模拟器运行程序时发生错误报“路径无效。请检查数据库的目录”。 symbol.sdf在程序的目录下 打开数据库的方法如下： public void opensql()        {            //SqlCommand cm = new System.Data.SqlClient.SqlCommand();            //SqlConnection cn = new SqlConnection();            SqlCeCommand cm = new SqlCeCommand();            SqlCeConnection cn = new SqlCeConnection();            //cn.ConnectionString = "Data Source=symbol.sdf";            //cn.ConnectionString = "server=JC91109;uid=sa;pwd=sa;database=symbol";            cn.ConnectionString = "data source=symbol.sdf";            cn.Open();            cm.Connection = cn;        }