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

namespace?WindowsFormsApplication2
{
????class?Connection
????{
????????private?static?string?sqlConnection?=?“Data?Source=.;Initial?Catalog=TrainOfChina;Integrated?Security=True“;?
????????private?SqlConnection?connection;

????????public?SqlConnection?Connection1
????????{
????????????get?{?
????????????????if（connection==null）
????????????????{
????????????????????connection?=?new?SqlConnection（sqlConnection）;
????????????????}
????????????????return?connection;
????????????}
????????}
????????public?void?OpenConnection（）
????????{
????????????if（Connection1.State==ConnectionState.Closed）
????????????{
????????????????Connection1.Open（）;?
????????????}
????????????else?if（Connection1.State==ConnectionState.Broken）?
????????????{
????????????????Connection1.Close（）;?
????????????????Connection1.Open（）;
????????????}
????????}
????????public?void?CloseConnection（）
????????{?
????????????if（Connection1.State==ConnectionState.Open||Connection1.State==ConnectionState.Broken）
????????????{
????????????????Connection1.Close（）;
????????????}
????????}
????}
}

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

?????文件????5242880??2020-04-13?12:14??ktv1\Employee.mdf

?????文件????2097152??2020-04-13?12:14??ktv1\Employee_log.ldf

?????文件????????217??2020-04-13?10:07??ktv1\SQLQuery1.sql

?????文件????????187??2020-04-13?09:14??ktv1\WindowsFormsApplication2\App.config

?????文件??????17408??2020-04-13?10:55??ktv1\WindowsFormsApplication2\bin\Debug\LhtFromtest.exe

?????文件????????187??2020-04-13?09:14??ktv1\WindowsFormsApplication2\bin\Debug\LhtFromtest.exe.config

?????文件??????40448??2020-04-13?10:55??ktv1\WindowsFormsApplication2\bin\Debug\LhtFromtest.pdb

?????文件??????22984??2020-04-26?17:26??ktv1\WindowsFormsApplication2\bin\Debug\LhtFromtest.vshost.exe

?????文件????????187??2020-04-13?09:14??ktv1\WindowsFormsApplication2\bin\Debug\LhtFromtest.vshost.exe.config

?????文件????????490??2019-03-19?12:46??ktv1\WindowsFormsApplication2\bin\Debug\LhtFromtest.vshost.exe.manifest

?????文件???????1285??2020-04-13?12:10??ktv1\WindowsFormsApplication2\Connection.cs

?????文件????????748??2020-04-13?12:16??ktv1\WindowsFormsApplication2\Form1.cs

?????文件???????5047??2020-04-13?12:17??ktv1\WindowsFormsApplication2\Form1.Designer.cs

?????文件???????6015??2020-04-13?09:35??ktv1\WindowsFormsApplication2\Form1.resx

?????文件???????3869??2020-04-13?12:17??ktv1\WindowsFormsApplication2\Form2.cs

?????文件??????11411??2020-04-13?12:16??ktv1\WindowsFormsApplication2\Form2.Designer.cs

?????文件???????5817??2020-04-13?10:42??ktv1\WindowsFormsApplication2\Form2.resx

?????文件????????863??2020-04-13?12:17??ktv1\WindowsFormsApplication2\obj\Debug\DesignTimeResolveAssemblyReferences.cache

?????文件???????6991??2020-04-26?17:26??ktv1\WindowsFormsApplication2\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache

?????文件????????196??2020-04-13?11:37??ktv1\WindowsFormsApplication2\obj\Debug\JS.csproj.FileListAbsolute.txt

?????文件???????1362??2020-04-13?11:21??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.csproj.FileListAbsolute.txt

?????文件???????1057??2020-04-13?10:42??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.csproj.GenerateResource.Cache

?????文件???????2211??2020-04-13?09:35??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.csprojResolveAssemblyReference.cache

?????文件??????17408??2020-04-13?10:55??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.exe

?????文件????????180??2020-04-13?10:42??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.frmAddEmployee.resources

?????文件????????180??2020-04-13?10:05??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.frmEmployeeSysMain.resources

?????文件??????40448??2020-04-13?10:55??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.pdb

?????文件????????180??2020-04-13?10:05??ktv1\WindowsFormsApplication2\obj\Debug\LhtFromtest.Properties.Resources.resources

?????文件??????????0??2020-04-13?09:14??ktv1\WindowsFormsApplication2\obj\Debug\TemporaryGeneratedFile_036C0B5B-1481-4323-8D20-8F5ADCB23D92.cs

?????文件??????????0??2020-04-13?09:14??ktv1\WindowsFormsApplication2\obj\Debug\TemporaryGeneratedFile_5937a670-0e60-4077-877b-f7221da3dda1.cs

............此處省略26個文件信息