using?System;
using?System.Collections.Generic;
using?System.Linq;
using?System.Text;
using?System.Threading.Tasks;
using?System.Data.SqlClient;
using?System.Data;

namespace?MyKTVSys
{
????public?class?DBHelper
????{
????????//數據庫連接字符串
????????public?string?conStr?=?@“Data?Source=.;Initial?Catalog=MyKTV;Integrated?Security=True“;

????????//連接數據庫
????????public?SqlConnection?conn;

????????public?SqlConnection?GetConn（）?{
????????????if（conn==null）{
????????????????conn?=?new?SqlConnection（conStr）;
????????????}
????????????return?conn;
????????}

????????//打開連接
????????public?void?OpenConn（）?{
????????????if（conn.State==ConnectionState.Broken）{
????????????????//先關閉在打開
????????????????conn.Close（）;
????????????????conn.Open（）;
????????????}else?if（conn.State==ConnectionState.Closed）{
????????????????conn.Open（）;
????????????}
????????}

????????//關閉連接
????????public?void?CloseConn（）?{
????????????if（conn.State==ConnectionState.Open||conn.State==ConnectionState.Broken）{
????????????????conn.Close（）;
????????????}
????????}

????}
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件????????187??2019-05-27?15:19??MyKTVSys\MyKTVSys\App.config

?????文件??????30208??2019-05-28?11:55??MyKTVSys\MyKTVSys\bin\Debug\MyKTVSys.exe

?????文件????????187??2019-05-27?15:19??MyKTVSys\MyKTVSys\bin\Debug\MyKTVSys.exe.config

?????文件??????73216??2019-05-28?11:55??MyKTVSys\MyKTVSys\bin\Debug\MyKTVSys.pdb

?????文件??????22984??2019-05-28?11:55??MyKTVSys\MyKTVSys\bin\Debug\MyKTVSys.vshost.exe

?????文件????????187??2019-05-27?15:19??MyKTVSys\MyKTVSys\bin\Debug\MyKTVSys.vshost.exe.config

?????文件????????490??2015-07-10?19:01??MyKTVSys\MyKTVSys\bin\Debug\MyKTVSys.vshost.exe.manifest

?????文件???????1151??2019-05-28?10:48??MyKTVSys\MyKTVSys\DBHelper.cs

?????文件????????397??2019-05-27?16:42??MyKTVSys\MyKTVSys\FrmAbount.cs

?????文件???????2902??2019-05-27?16:42??MyKTVSys\MyKTVSys\FrmAbount.Designer.cs

?????文件???????5817??2019-05-27?16:42??MyKTVSys\MyKTVSys\FrmAbount.resx

?????文件???????4152??2019-05-28?11:56??MyKTVSys\MyKTVSys\FrmFindAllSingerInfo.cs

?????文件??????11452??2019-05-28?11:55??MyKTVSys\MyKTVSys\FrmFindAllSingerInfo.Designer.cs

?????文件???????7166??2019-05-28?11:55??MyKTVSys\MyKTVSys\FrmFindAllSingerInfo.resx

?????文件????????421??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSingerTypeInfo.cs

?????文件???????6584??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSingerTypeInfo.Designer.cs

?????文件???????6404??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSingerTypeInfo.resx

?????文件????????409??2019-05-28?14:12??MyKTVSys\MyKTVSys\FrmFindSongInfo.cs

?????文件??????11236??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSongInfo.Designer.cs

?????文件???????7318??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSongInfo.resx

?????文件????????417??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSongTypeInfo.cs

?????文件???????4128??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSongTypeInfo.Designer.cs

?????文件???????6573??2019-05-27?16:41??MyKTVSys\MyKTVSys\FrmFindSongTypeInfo.resx

?????文件????????575??2019-05-27?16:21??MyKTVSys\MyKTVSys\FrmLogin.cs

?????文件???????5248??2019-05-27?16:19??MyKTVSys\MyKTVSys\FrmLogin.Designer.cs

?????文件???????5817??2019-05-27?16:19??MyKTVSys\MyKTVSys\FrmLogin.resx

?????文件???????1743??2019-05-27?16:26??MyKTVSys\MyKTVSys\FrmMain.cs

?????文件??????12897??2019-05-27?16:25??MyKTVSys\MyKTVSys\FrmMain.Designer.cs

?????文件???????6015??2019-05-27?16:25??MyKTVSys\MyKTVSys\FrmMain.resx

?????文件????????500??2019-05-28?10:33??MyKTVSys\MyKTVSys\FrmUpdatePass.cs

............此處省略42個文件信息