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

namespace?畢設(shè)選題系統(tǒng)C
{
????class?DBAccess
????{
????????#region??全局變量
????????//定義全局變量，記錄“基礎(chǔ)信息”各窗體中的表名及SQL語句
????????public?static?string?strSQLCmdString?=?““?strTable?=?““?strField?=?““;
????????//定義一個(gè)SqlConnection類型的公共變量My_con，用于判斷數(shù)據(jù)庫(kù)是否連接成功
????????public?static?SqlConnection?sqlConnection;
????????public?static?string?strSQLConnection?=?“server=（local）;database=畢設(shè)管理系統(tǒng);uid=sa;pwd=123456“;
????????public?static?int?nLoginType?=?0;????????????//用戶登錄與重新登錄的標(biāo)識(shí)
????????public?static?DBAccess?dbAccess;
????????public?static?double?Balance?=?0;//?當(dāng)前余額

????????#endregion

????????#region??讀取配置文件
????????public?static?bool?LoadConfiguration（）
????????{
????????????FileStream?fileStream?=?null;
????????????StreamReader?streamReader?=?null;
????????????try
????????????{
????????????????fileStream?=?new?FileStream（“Configuration.txt“?FileMode.Open?FileAccess.Read）;
????????????????streamReader?=?new?StreamReader（fileStream）;
????????????????strSQLConnection?=?streamReader.ReadLine（）;
????????????????return?true;
????????????}
????????????catch?（Exception）
????????????{
????????????????if?（streamReader?!=?null）
????????????????{
????????????????????streamReader.Close（）;
????????????????}
????????????????MessageBox.Show（“配置文件讀取錯(cuò)誤！“）;
????????????????return?false;
????????????}
????????}

????????#endregion

????????#region??建立數(shù)據(jù)庫(kù)連接
????????public?static?SqlConnection?GetConnection（）
????????{
????????????sqlConnection?=?new?SqlConnection（strSQLConnection）;????//用SqlConnection對(duì)象與指定的數(shù)據(jù)庫(kù)相連接
????????????sqlConnection.Open（）;???????????????????????????????????//打開數(shù)據(jù)庫(kù)連接
????????????return?sqlConnection;???????????????????????????????????//返回SqlConnection對(duì)象的信息
????????}
????????#endregion

????????#region??測(cè)試數(shù)據(jù)庫(kù)是否賦加
????????public?void?OpenConnection（）
????????{
????????????GetConnection（）;
????????????//CloseConnection（）;
????????}
????????#endregion

????????#region??關(guān)閉數(shù)據(jù)庫(kù)連接
????????public?void?CloseConnection（）
????????{
????????????if?（sqlConnection.State?==?ConnectionState.Open）???//判斷是否打開與數(shù)據(jù)庫(kù)的連接
????????????{
????????????????sqlConnection.Close（）;???//關(guān)閉數(shù)據(jù)庫(kù)的連接
????????????????sqlConnection.Dispose（）;???//釋放My_con變量的所有空間
????????????}
????????}
????????#endregion

????????#region??讀取指定表中的信息
????????public?SqlDataReader?GetReaderofCommand（string?SQLstr）
????????{
????????????GetConnection（）;???//打開與數(shù)據(jù)庫(kù)的連接
????????????SqlCommand?sqlCommand?=?sqlConnection.CreateCommand（）;?//創(chuàng)建一個(gè)SqlCommand對(duì)象，用于執(zhí)行SQL語句
????????????sqlCommand.CommandText?=?SQLstr;????//獲取指定的SQL語句
????????????SqlDataReader?dataReader?=?sqlCommand.ExecuteReader（）;?//執(zhí)行SQL語名句，生成一個(gè)SqlDataReader對(duì)象
????????????return?dataReader;
????????}
????????#endregion?執(zhí)行帶參數(shù)的Sql語句，無返回值
????????public?void?GetSQLCommand（st

?屬性????????????大小?????日期????時(shí)間???名稱
-----------?---------??----------?-----??----
?????文件????????8983??2020-06-28?10:13??畢設(shè)選題系統(tǒng)?.sql
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\.vs\
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\
?????文件???????61440??2020-06-25?12:02??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\.suo
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\Server\
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\Server\sqlite3\
?????文件???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\Server\sqlite3\db.lock
?????文件??????675840??2020-06-25?11:55??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\Server\sqlite3\storage.ide
?????文件???????32768??2020-06-25?08:12??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\Server\sqlite3\storage.ide-shm
?????文件?????4136512??2020-06-25?12:00??畢設(shè)選題系統(tǒng)C\.vs\畢設(shè)選題系統(tǒng)C\v15\Server\sqlite3\storage.ide-wal
?????目錄???????????0??2020-06-25?12:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\
?????文件????????1155??2020-06-24?20:11??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C.sln
?????文件?????????189??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\App.config
?????目錄???????????0??2020-06-24?20:04??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\bin\
?????目錄???????????0??2020-06-24?20:11??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\bin\Debug\
?????文件??????116736??2020-06-25?12:01??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\bin\Debug\畢設(shè)選題系統(tǒng)C.exe
?????文件?????????189??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\bin\Debug\畢設(shè)選題系統(tǒng)C.exe.config
?????文件??????249344??2020-06-25?12:01??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\bin\Debug\畢設(shè)選題系統(tǒng)C.pdb
?????目錄???????????0??2020-06-24?20:04??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\bin\Release\
?????文件????????5629??2020-06-24?20:10??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\DBAccess.cs
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\
?????目錄???????????0??2020-06-25?12:01??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\
?????文件????????1443??2020-06-25?08:19??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\DesignTimeResolveAssemblyReferences.cache
?????文件????????7296??2020-06-25?11:55??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache
?????文件???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\TemporaryGeneratedFile_036C0B5B-1481-4323-8D20-8F5ADCB23D92.cs
?????文件???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\TemporaryGeneratedFile_5937a670-0e60-4077-877b-f7221da3dda1.cs
?????文件???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\TemporaryGeneratedFile_E7A71F73-0F8D-4B9B-B56E-8E70B10BC5D3.cs
?????目錄???????????0??2020-06-24?20:02??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\TempPE\
?????文件??????????42??2020-06-25?11:55??畢設(shè)選題系統(tǒng)C\畢設(shè)選題系統(tǒng)C\obj\Debug\畢設(shè)選題系統(tǒng)C.csproj.CoreCompileInputs.cache
............此處省略107個(gè)文件信息