学生管理系统用C++实现的

namespace StudentManager { public class DBHelper { /// <summary> /// 获得连接字符串,使用sql数据库 /// </summary> private static string constring ="server=.;uid=sa;database=StudentManager;pwd="; /// <summary> /// 执行增删改操作 /// </summary> /// <param name="sql">传入增删改的sql语句</param> /// <returns>返回受影响的行数</returns> public static int ExecuteNonQuery(string sql) { int i=0; using(SqlConnection con = new SqlConnection(constring)) { using (SqlCommand cmd = new SqlCommand(sql,con)) { con.Open(); i= cmd.ExecuteNonQuery(); con.Close(); } } return i; } /// <summary> /// 执行查询操作 /// </summary> /// <param name="sql">查询语句</param> /// <returns>返回查询结果</returns> public static SqlDataReader ExecuteReader(string sql) { SqlConnection con = new SqlConnection(constring); SqlCommand cmd = new SqlCommand(sql, con); cmd.Connection.Open(); return cmd.ExecuteReader(CommandBehavior.CloseConnection); } } } 工厂类 public class Factory { public static IStudent CreateStudentDAL() { IStudent idal = null; //从配置文件中加载程序集的名称 string 程序集 = System.Configuration.ConfigurationManager.AppSettings["程序集"]; string 命名空间 = System.Configuration.ConfigurationManager.AppSettings["命名空间"]; //从配置文件中加载数据访问层的名称 string 类 = System.Configuration.ConfigurationManager.AppSettings["类"]; //通过反射创建数据访问对象 idal = (IStudent)Assembly.Load(程序集).CreateInstance(命名空间+"."+类); return idal; } } form1 namespace StudentManager { public partial class Form1 : Form { // bool Flag = false;//标志位，表示用户是否选择过要修改或删除的数据行。 int id; //通过工厂创建对象 IStudent studal = Factory.CreateStudentDAL(); public Form1() { InitializeComponent(); } /// <summary> /// 窗体加载时，显示所有信息 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void Form1_Load(object sender, EventArgs e) { dataGridView1.ReadOnly = true;//不允许用户修改行 SE.SkinFile = Application.StartupPath + "\\skin\\OneGreen.ssk"; StudentView(); } private void StudentView() { dataGridView1.DataSource = studal.GetAll(); } //查看学生信息 private void btnView_Click(object sender, EventArgs e) { StudentView(); } //添加学生信息 private void btnAdd_Click(object sender, EventArgs e) { if (txtName.Text == "" || txtAge.Text == "") {