关于vs2015 里连接sql ce数据库的问题求助

下面是部分代码，运行到conn.Open();时出错，详细提示为没找到路径，可我给的路径是对的啊
    public partial class Form1 : Form
    {
        private void UpdateDB()
        {
            SqlCeConnection conn = new SqlCeConnection (@"Data Source = C:\blankform.sdf,Persist Security Info=False;Password=");
            //using (SqlCeCommand comm = new SqlCeCommand(ssFiltrate0, conn))
            conn.Open();