GWSocketClient/GWSocketClient/db/AccsessDbLoader.cs

using System;
using System.Collections.Generic;
using System.Data;
using System.Data.OleDb;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using GWSocketClient.model;
using Newtonsoft.Json;

namespace GWSocketClient.db
{
    class AccsessDbLoader
    {
        private static AccsessDbLoader INSTANCE = null;

        private DataTable dataTable = new DataTable();
        private OleDbDataAdapter dataAdapter;

        private List<WvBean> wvBeans = new List<WvBean>();
        public Dictionary<string, string> ID_INFO = new Dictionary<string, string>();

        public static AccsessDbLoader getInstance(string dbssPath = "")
        {
            return INSTANCE ?? (INSTANCE = new AccsessDbLoader(dbssPath));
        }

        public DataTable getDataTable()
        {
            return dataTable;
        }


        public OleDbDataAdapter getDataAdapter()
        {
            return dataAdapter;
        }

        public Dictionary<string, string> getUserIdInfo()
        {
            return ID_INFO;
        }

        public string getWebViewJson()
        {
            return JsonConvert.SerializeObject(wvBeans);
        }

        private AccsessDbLoader(string dbPath = "")
        {
            if (dbPath.Equals(""))
            {
                dbPath = Application.StartupPath + "/dbfile/ID_INFO.accdb;";
            }
            reloadAccessDb(dbPath);
        }


        public AccsessDbLoader reloadAccessDb(string dbPath)
        {
            OleDbConnection mycon = null;
            OleDbDataReader myReader = null;

            OleDbCommand sqlcmd = null;

            string strConnection = "Provider = Microsoft.ACE.OLEDB.12.0;" + "Data Source = " + dbPath;

            try
            {
                using (OleDbConnection objConnection = new OleDbConnection(strConnection))
                {
                    objConnection.Open();
                    sqlcmd = new OleDbCommand(@"select * from fw", objConnection); //sql语句     


                    dataAdapter = new OleDbDataAdapter(sqlcmd);

                    dataAdapter.Fill(dataTable);

                    using (OleDbDataReader reader = sqlcmd.ExecuteReader())
                    {
                        if (reader.Read()) //这个read调用很重要！不写的话运行时将提示找不到数据  
                        {
                            WvBean wb = new WvBean();
                            int id = 0;
                            int index = 0;
                            string myId = "";
                            string idInfo = "";
                            string len = "";
                            string mode = "";
                            string desp = "";
                            string defalutValue = "";
                            string userValue = "";
                            string remark = "";
                            try
                            {
                                id = reader.GetInt32(0);
                                index = reader.GetInt32(1);
                                myId = reader.GetString(2);
                                idInfo = calcNull(reader.GetString(3));
                                len = calcNull(reader.GetString(4));
                                mode = calcNull(reader.GetString(5));
                                desp = calcNull(reader.GetString(6));
                                defalutValue = calcNull(reader.GetString(7));
                                userValue = calcNull(reader.GetString(8));
                                remark = calcNull(reader.GetString(9));
                            }
                            catch (Exception exception)
                            {
                            }

                            wb.id = id;
                            wb.index = index;
                            wb.myId = myId;
                            wb.idInfo = idInfo;
                            wb.len = len;
                            wb.mode = mode;
                            wb.desp = desp;
                            wb.defalutValue = defalutValue;
                            wb.userValue = userValue;
                            wb.remark = remark;

                            ID_INFO.Add(myId, userValue);

                            wvBeans.Add(wb);
                        }
                    }
                }
                return this;
            }
            catch (OleDbException oe)
            {
                MessageBox.Show(oe.Message);
            }
            catch (Exception exception)
            {
                MyMessageBox.ShowMessageBox(exception.Message);
            }

            return null;
        }

        private string calcNull(string ojb)
        {
            if (ojb.Trim().Equals("") || ojb == null)
            {
                return "";
            }
            return ojb;
        }
    }
}