SQLCE 连接时候的路径有关问题

public partial class Form1 : Form    {        string appPath;        public Form1()        {            InitializeComponent();         }        private void Form1_Load(object sender, EventArgs e)        {            appPath = System.IO.Path.Combine(System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase), "ioriDB6.sdf");            createDataBase();        }        private void createDataBase()        {            if (System.IO.File.Exists(appPath))            {                //存在            }            else            {                                                    System.Data.SqlServerCe.SqlCeEngine eng = new System.Data.SqlServerCe.SqlCeEngine("Data Source=" + appPath);                    eng.CreateDatabase();                    //连接ce数据库                    System.Data.SqlServerCe.SqlCeConnection localcnn = new System.Data.SqlServerCe.SqlCeConnection(appPath);  //就是这句出现的“从索引 0 处开始，初始化字符串的格式不符合规范。”                    localcnn.Open();                    StringBuilder sql = new StringBuilder();                    sql.Append( "CREATE TABLE user(id varchar(6) primary key not null,name varchar(8),sec char(2))");                    System.Data.SqlServerCe.SqlCeCommand cmdSQL = new System.Data.SqlServerCe.SqlCeCommand(sql.ToString(), localcnn);                    cmdSQL.CommandType = System.Data.CommandType.Text;                    cmdSQL.ExecuteNonQuery();                                            }        }    }