【C#】简单三层架构(MVC)实现学生信息管理
一个简单的demo，代码不多，适合初学者。
三层架构分别是:表示层(UI)、业务逻辑层(NLL)、数据访问层(DAL).
视频讲解教程:
微课7-1三层架构的搭建-----https://2d.hep.com.cn/47486/98
微课7-2显示学生信息--------https://2d.hep.com.cn/47486/99
微课7-3添加学生信息--------https://2d.hep.com.cn/47486/100
微课7-4修改学生信息--------https://2d.hep.com.cn/47486/101
微课7-5删除学生信息--------https://2d.hep.com.cn/47486/102
源代码下载地址: https://www.lanzous.com/i2lfucf
注意:
1.数据库在TriStu\bin\debug目录下
2.需要在DBHelper改数据库连接字符串
一、数据库（StuDB）
数据库表的名称
表名:T_Stu
数据库表的结构及数据
二、项目概览
1.总体图
TriStu---表示层
TriStu.BLL---业务逻辑层
TriStu.DAL---数据访问层
TriStu.Models---实体类
2.软件运行截图
三:实现代码
1.Form1.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using TriStu.BLL;
using TriStu.Models;
namespace TriStu
{
public partial class Form1 : Form
{
StuManager stu=new StuManager();
public Form1()
{
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e)
{
dataGridView1.DataSource = stu.GetStudentList();
}
private void btnAdd_Click(object sender, EventArgs e)
{
Student newStu = new Student();
newStu.ID = int.Parse(txtID.Text);
newStu.Name = txtName.Text;
newStu.Age = int.Parse(txtAge.Text);
if (stu.AddStudent(newStu))
{
MessageBox.Show("添加成功");
dataGridView1.DataSource = stu.GetStudentList();
}
else
{
MessageBox.Show("添加失败");
}
}
private void dataGridView1_CellClick(object sender, DataGridViewCellEventArgs e)
{
//判断是否选中dataGridView1里的一行
if (dataGridView1.SelectedRows.Count <= 0)
{
MessageBox.Show("请选择一行进行操作");
return;
}
txtID.Text = dataGridView1.SelectedRows[0].Cells[0].Value.ToString();
txtName.Text = dataGridView1.SelectedRows[0].Cells[1].Value.ToString();
txtAge.Text = dataGridView1.SelectedRows[0].Cells[2].Value.ToString();
}
private void btnUpdate_Click(object sender, EventArgs e)
{
//判断是否选中dataGridView1里的一行
if (dataGridView1.SelectedRows.Count <= 0)
{
MessageBox.Show("请选择一行进行操作");
return;
}
Student newStu = new Student();
newStu.ID = int.Parse(dataGridView1.SelectedRows[0].Cells[0].Value.ToString());
newStu.Name = txtName.Text;
newStu.Age = int.Parse(txtAge.Text);
//保存修改
if (stu.UpdateStudent(newStu))
{
MessageBox.Show("修改成功");
dataGridView1.DataSource = stu.GetStudentList();
}
else
{
MessageBox.Show("修改失败");
}
}
private void btnDel_Click(object sender, EventArgs e)
{
int id;
if (dataGridView1.SelectedRows.Count <= 0)
{
MessageBox.Show("请选中一行进行操作");
return;
}
id = int.Parse(dataGridView1.SelectedRows[0].Cells[0].Value.ToString());
//删除
if (stu.DelStudent(id))
{
MessageBox.Show("删除成功");
dataGridView1.DataSource = stu.GetStudentList();
txtID.Text = "";
txtName.Text = "";
txtAge.Text = "";
}
else
{
MessageBox.Show("删除失败");
}
}
}
}
2.StuManager.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TriStu.DAL;
using TriStu.Models;
namespace TriStu.BLL
{
public class StuManager
{
StuService stu = new StuService();
public List GetStudentList()
{
return stu.GetStudentList();
}
#region 添加学生
///
/// 添加学生
///
/// 学生
/// 返回bool值
public bool AddStudent(Student newStu)
{
return stu.AddStudent(newStu);
}
#endregion
#region 修改学生信息
///
/// 修改学生信息
///
/// 学生
/// 返回bool值
public bool UpdateStudent(Student s)
{
return stu.UpdateStudent(s);
}
#endregion
public bool DelStudent(int id)
{
return stu.DelStudent(id);
}
}
}
3.DBHelper.cs
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Transactions;
namespace TriStu.DAL
{
public class DBHelper
{
//数据库连接字符串--记得改
public static string connString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\24040\source\repos\TriStu\TriStu\bin\Debug\StuDB.mdf;Integrated Security=True;Connect Timeout=30";
//定义数据库连接对象
public static SqlConnection conn = new SqlConnection(connString);
#region 获取数据的方法
///
/// 获取数据的方法
///
/// select语句
/// 返回DaraTable对象
public static DataTable GetDataTable(string sqlStr)
{
try
{
conn.Open();
SqlCommand cmd = new SqlCommand(sqlStr, conn);
SqlDataAdapter dapt = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
dapt.Fill(dt);
return dt;
}
catch (Exception ex)
{
return null;
//throw ex;
}
finally
{
conn.Close();
}
}
#endregion
#region 获取数据的重载方法
///
/// 获取数据的重载方法
///
/// select语句
/// SqlParameter对象数组
/// 返回DataTable对象
public static DataTable GetDataTable(string sqlStr, SqlParameter[] param)
{
try
{
conn.Open();
SqlCommand cmd = new SqlCommand(sqlStr,conn);
cmd.Parameters.AddRange(param);
SqlDataAdapter dapt = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
dapt.Fill(dt);
return dt;
}
catch (Exception ex)
{
return null;
//throw ex;
}
finally
{
conn.Close();
}
}
#endregion
#region 执行更新方法
///
/// 执行更新方法
///
/// insert|update|delete语句
/// 返回一个bool值
public static bool ExcuteCommand(string sqlStr)
{
try
{
//conn.Open();
SqlCommand cmd = new SqlCommand(sqlStr, conn);
conn.Open();
cmd.ExecuteNonQuery();
return true;
}
catch (Exception ex)
{
return false;
//throw ex;
}
finally
{
conn.Close();
}
}
#endregion
#region 执行更新的重载方法
///
/// 执行更新的重载方法
///
/// insert|update|delete语句
/// SqlParameter对象数组
/// 返回一个bool值
public static bool ExcuteCommand(string sqlStr, SqlParameter[] param)
{
try
{
conn.Open();
SqlCommand cmd = new SqlCommand(sqlStr, conn);
cmd.Parameters.AddRange(param);
cmd.ExecuteNonQuery();
return true;
}
catch (Exception ex)
{
return false;
//throw ex;
}
finally
{
conn.Close();
}
}
#endregion
public static bool ExcuteCommand(List sqlStr, List param)
{
int i = 0;
SqlCommand cmd = new SqlCommand();
using (TransactionScope ts = new TransactionScope())
{
cmd.Connection = conn;
conn.Open();
try
{
foreach (string item in sqlStr)
{
//设置命令类型为SQL文本命令
cmd.CommandType = CommandType.Text;
//设置对数据源执行的SQL语句
cmd.CommandText = item;
//添加参数
cmd.Parameters.AddRange(param[i]);
//执行SQL语句并返回受影响的行数
cmd.ExecuteNonQuery();
i++;
}
ts.Complete();
return true;
}
catch(Exception ex)
{
throw ex;
return false;
}
finally
{
conn.Close();
sqlStr.Clear();
}
}
}
}
}
4.StuService.cs
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using TriStu.Models;
namespace TriStu.DAL
{
public class StuService
{
public List GetStudentList()
{
string sqlstr = "select * from T_Stu";
DataTable dt = DBHelper.GetDataTable(sqlstr);
List list = new List();
foreach(DataRow r in dt.Rows)
{
Student stu = new Student();
stu.ID = int.Parse(r["ID"].ToString());
stu.Name = r["name"].ToString();
stu.Age = int.Parse(r["age"].ToString());
list.Add(stu);
}
return list;
}
#region 添加学生信息
///
/// 添加学生信息
///
/// 学生
/// 返回bool值
public bool AddStudent(Student newStu)
{
string sqlStr = "insert into T_Stu values(@ID,@name,@age)";
SqlParameter[] param = new SqlParameter[]
{
new SqlParameter("@ID",newStu.ID),
new SqlParameter("@name",newStu.Name),
new SqlParameter("@age",newStu.Age)
};
return DBHelper.ExcuteCommand(sqlStr, param);
}
#endregion
#region 修改学生信息
///
/// 修改学生信息
///
/// 学生
/// 返回bool值
public bool UpdateStudent(Student stu)
{
string sqlstr = "update T_Stu set name=@name,age=@age where ID=@id";
SqlParameter[] param = new SqlParameter[]
{
new SqlParameter("@ID",stu.ID),
new SqlParameter("@name",stu.Name),
new SqlParameter("@age",stu.Age)
};
return DBHelper.ExcuteCommand(sqlstr, param);
}
#endregion
public bool DelStudent(int id)
{
List strSqls = new List();
List param = new List();
string strDeletel = "DELETE from T_Stu where ID=@id";
strSqls.Add(strDeletel);
SqlParameter[] param1 = new SqlParameter[]
{
new SqlParameter("@ID",id)
};
param.Add(param1);
//新增的未加入到T_Sc表，这里不删除这个表的数据
//string strDelete2 = "DELETE from T_Stu where Sno=@sno";
//strSqls.Add(strDelete2);
//SqlParameter[] param2 = new SqlParameter[]
//{
// new SqlParameter("@sno",id)
//};
//param.Add(param2);
return DBHelper.ExcuteCommand(strSqls, param);
}
}
}
5.Student.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace TriStu.Models
{
public class Student
{
public int ID { get; set; }
public string Name { get; set; }
public int Age { get; set; }
public Student(){}
#region 构造方法
///
/// 构造方法
///
/// ID
/// 姓名
/// 年龄
public Student(int ID, string name, int age)
{
this.ID = ID;
this.Name = Name;
this.Age = Age;
}
#endregion
}
}