public class DbHelpersqlite
    {
        public string connectionString = "Data Source=" + AppDomain.CurrentDomain.BaseDirectory + @"WIP.db;Version=3;";


        public event EventHandler<sqliteMessageEventArg> sqliteMessageEvent;


        public DbHelpersqlite()
        { }
   
        /// <summary>
        /// 執行單條sql語句，返回值(bool)
        /// </summary>
        /// <param name="sqlString"></param>
        /// <returns></returns>
        public bool Executesql(string sqlString)
        {
            var eventHandle = sqliteMessageEvent;
            string msg = "";


            using (sqliteConnection connection = new sqliteConnection(connectionString))
            {
                using (sqliteCommand cmd = new sqliteCommand(sqlString,connection))
                {
                    try
                    {
                        connection.Open();
                        cmd.ExecuteNonQuery();
                        msg = "sql Command: " + sqlString + " Excute Success!";
                        if (eventHandle != null)
                        {
                            eventHandle(null,new sqliteMessageEventArg(sqliteMessageType.Msg,msg,sqlString));
                        }
                        return true;
                    }
                    catch (sqliteException ex)
                    {
                        msg = "Execute sql Error Message: " + ex.Message;
                        if (eventHandle != null)
                        {
                            eventHandle(null,new sqliteMessageEventArg(sqliteMessageType.Errorsql,sqlString));
                        }
                        return false;
                    }
                    finally
                    {
                        connection.Close();
                        cmd.Dispose();
                    }
                }
            }
        }

        /// <summary>
        /// 獲取最大值，返回值(int)
        /// </summary>
        /// <param name="FieldName">欄位名稱</param>
        /// <param name="TableName">表名稱</param>
        /// <returns></returns>
        public int GetMaxID(string FieldName,string TableName)
        {
            string strsql = "select max(" + FieldName + ")+1 from " + TableName;
            object obj = GetSingle(strsql);
            if (obj == null)
            {
                return 1;
            }
	    return int.Parse(obj.ToString());
        }

        /// <summary>
        /// 單值查詢，返回查詢結果(Object)
        /// </summary>
        /// <param name="sqlString"></param>
        /// <returns></returns>
        public object GetSingle(string sqlString)
        {
            var eventHandle = sqliteMessageEvent;
            string msg = "";


            using (sqliteConnection connection = new sqliteConnection(connectionString))
            {
                using (sqliteCommand cmd = new sqliteCommand(sqlString,connection))
                {
                    try
                    {
                        connection.Open();
                        object obj = cmd.ExecuteScalar();
                        if ((Object.Equals(obj,null)) || (Object.Equals(obj,System.DBNull.Value)))
                        {
                            msg = "WARN : sql Command Return null! [ " + sqlString + "]";
                            if (eventHandle != null)
                            {
                                eventHandle(null,sqlString));
                            }
                            return null;
                        }
                        else
                        {
                            msg = "sql Command: " + sqlString + " Excute Success!";
                            if (eventHandle != null)
                            {
                                eventHandle(null,sqlString));
                            }
                            return obj;
                        }
                    }
                    catch (sqliteException e)
                    {
                        msg = "Execute sql Error Message: " + e.Message;
                        if (eventHandle != null)
                        {
                            eventHandle(null,sqlString));
                        }
                        connection.Close();
                        return null;
                    }
                    finally
                    {
                        connection.Close();
                        cmd.Dispose();
                    }
                    
                }
            }
        }

        /// <summary>
        /// 執行多條sql語句，實現數據庫事務
        /// </summary>
        /// <param name="sqlStringList"></param>
        public void ExcutesqlTran(ArrayList sqlStringList)
        {
            var eventHandle = sqliteMessageEvent;
            string msg = "";
            using (sqliteConnection conn = new sqliteConnection(connectionString))
            {
                conn.Open();
                sqliteCommand cmd = new sqliteCommand();
                cmd.Connection = conn;
                sqliteTransaction tx = conn.BeginTransaction();
                cmd.Transaction = tx;
                try
                {
                    for (int n = 0; n < sqlStringList.Count; n++)
                    {
                        string strsql = sqlStringList[n].ToString();
                        if (strsql.Trim().Length > 1)
                        {
                            cmd.CommandText = strsql;
                            cmd.ExecuteNonQuery();
                            msg = "sql Command: " + strsql + " Excute Success!";
                            if (eventHandle != null)
                            {
                                eventHandle(null,strsql));
                            }
                        }
                        else
                        {
                            msg = "Execute sql Error Message: strsql.Trim().Length=" + strsql.Trim().Length.ToString();
                            if (eventHandle != null)
                            {
                                eventHandle(null,strsql));
                            }
                        }
                    }
                    tx.Commit();
                }
                catch (sqliteException ex)
                {
                    tx.Rollback();
                    msg = "Execute sql Error Message: " + ex.Message;
                    if (eventHandle != null)
                    {
                        eventHandle(null,"[ExcutesqlTran]"));
                    }
                }
                finally
                {
                    conn.Close();
                    cmd.Dispose();
                }
            }
        }

        /// <summary>
        /// 執行單條sql語句，返回值(DataTable)
        /// </summary>
        /// <param name="sqlString"></param>
        /// <returns></returns>
        public DataTable SelectUse(string sqlString)
        {
            var eventHandle = sqliteMessageEvent;
            string msg = "";


            sqliteCommand cmd = null;
            sqliteDataAdapter oda = null;
            sqliteConnection connection = null;
            DataTable dt;
            try
            {
                connection = new sqliteConnection(connectionString);
                cmd = new sqliteCommand(sqlString,connection);
                connection.Open();
                dt = new DataTable();
                cmd.Transaction = connection.BeginTransaction();
                oda = new sqliteDataAdapter(cmd);
                oda.Fill(dt);


                msg = "sql Command: " + sqlString + " Excute Success!";
                if (eventHandle != null)
                {
                    eventHandle(null,sqlString));
                }


                return dt;


            }
            catch (sqliteException ex)
            {
                msg = "Execute sql Error Message: " + ex.Message;
                if (eventHandle != null)
                {
                    eventHandle(null,sqlString));
                }
                return null;
            }
            finally
            {
                connection.Close();
                cmd.Dispose();
                oda.Dispose();
            }
        }

        /// <summary>
        /// 測試DB連接
        /// </summary>
        /// <returns></returns>
        public bool ConnectConfirm()
        {
            var sqlStr = "select 1+1 from A";   //A是sqlite DB中的表
            var result = SelectUse(sqlStr);
            if (result != null)
            {
                if (result.Rows.Count == 0)
                {
                    return false;
                }
                return true;
            }
            else
            {
                return false;
            }
        }
    
    }

/// <summary>
    /// 回復事件
    /// </summary>
    public class sqliteMessageEventArg:EventArgs
    {
        public sqliteMessageType EventId { get; private set; }


        public string EventData{get;private set;}


        public string sqlCommand { get; private set; }


        public sqliteMessageEventArg(sqliteMessageType type,string data,string Strsql)
        {
            EventId = type;
            EventData = data;
            sqlCommand = Strsql;
        }
    }


    public enum sqliteMessageType
    {
        None = 0,Info = 1,Msg = 2,Error = 3,Errorsql = 4,ConnectBroken = 5,Others = 9
    }

//=======================主界面================================
        static void Main(string[] args)
        {
            bHelpersqlite _DB = new DbHelpersqlite();
            _DB.sqliteMessageEvent += new EventHandler<sqliteMessageEventArg>(_DB_sqliteMessageEvent);
            string _sql = "select Seq,cstid,D_Time,flag from w_CSTinfo";
            DataTable _dt=_DB.SelectUse(_sql);
	    ... ...
        }

        /// <summary>
        /// DB執行對象返回事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void _DB_sqliteMessageEvent(object sender,sqliteMessageEventArg e)
        {
            switch (e.EventId)
            { 
                case sqliteMessageType.Msg:
                    MessageBox.Show(e.EventData);
                    break;
                case sqliteMessageType.Error:
                    MessageBox.Show(e.EventData + ",sql: " + e.sqlCommand);
                    break;
                case sqliteMessageType.Errorsql:
                    MessageBox.Show(e.EventData);
                    break;
                default:
                    break;
            }
        }