四个数混合运算，数据库存题，程序集构建三层建构

1.Model类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Model
{
  
   public class TIModel
    {
        private string number1;
        private string number2;
        private string number3;
        private string number4;
        private string operation1;
        private string operation2;
        private string operation3;
        public string Number1
        {
            get
            {
                return number1;
            }
            set
            {
                number1 = value;
            }

        }
        public string Number2
        {
            get
            {
                return number2;
            }
            set
            {
                number2 = value;
            }

        }
        public string Number3
        {
            get
            {
                return number3;
            }
            set
            {
                number3 = value;
            }

        }
        public string Number4
        {
            get
            {
                return number4;
            }
            set
            {
                number4 = value;
            }

        }
        public string Operation1
        {
            get
            {
                return operation1;
            }
            set
            {
                operation1 = value;
            }
        }
        public string Operation2
        {
            get
            {
                return operation2;
            }
            set
            {
                operation2 = value;
            }
        }
        public string Operation3
        {
            get
            {
                return operation3;
            }
            set
            {
                operation3 = value;
            }
        }
    }
}

2.Tool公共类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Data;

namespace Tool
{
   
    public class SqlDBhelper
    {
        string constr = "Data Source=.;Initial Catalog=TIKUDB;Integrated Security=True";
        public SqlConnection conn = new SqlConnection();
        public DataSet ds = new DataSet();
        public DataTable dt = new DataTable();
        public SqlDataAdapter sda = new SqlDataAdapter();
        public void dbcon()//连接数据库！
        {

            conn = new SqlConnection(constr);


        }
        public void opens()//打开数据库！
        {
            conn.Open();
        }
        public void closes()//关闭数据库！
        {
            conn.Close();
        }
        public int Inster(string comstr,SqlParameter[] values)//插入数据！
        {
            int a = 0;
            dbcon();
            SqlCommand comm = new SqlCommand(comstr, conn);
            if (values != null)
            {
                comm.Parameters.AddRange(values);
            }
            opens();
            try
            {
                a = comm.ExecuteNonQuery();

            }
            finally
            {
                closes();
            }
            return a;


        }
        public DataTable Read(string comstr)//读取数据！
        {
            dbcon();
            sda = new SqlDataAdapter(comstr, conn);
            sda.Fill(ds);
            dt = ds.Tables[0];
            return dt;


        }
        public int execSql(string comstr)//删除数据！
        {
            dbcon();
            int a = 0;
            SqlCommand comm = new SqlCommand(comstr, conn);
            opens();
            try
            {
                a = comm.ExecuteNonQuery();
            }
            finally
            {
                closes();
            }
            return a;

        }
    }
}

　3.　DAL数据库访问类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Tool;
using Model;
using System.Data;
using System.Data.SqlClient;

namespace DAL
{
  
    public class TIDAL
    {
        SqlDBhelper helper = new SqlDBhelper();
        public DataTable Read()
        {
            string sql = "select * from TI";
            return helper.Read(sql);
        }
        public int InsterTI(TIModel rn)
        {
            string sql = "insert into TI values(@number1,@operation1,@number2,@operation2,@number3,@operation3,@number4)";
            SqlParameter[] parms =
            {
                new SqlParameter("@number1",rn.Number1),
                new SqlParameter("@operation1",rn.Operation1),
                new SqlParameter("@number2",rn.Number2),
                new SqlParameter("@operation2",rn.Operation2),
                new SqlParameter("@number3",rn.Number3),
                new SqlParameter("@operation3",rn.Operation3),
                new SqlParameter("@number4",rn.Number4)

            };
            return helper.Inster(sql, parms);
        }
        public int Delete()
        {
            string sql = "truncate table TI";
            return helper.execSql(sql);
        }

    }
   
}

4.BLL业务逻辑类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Model;
using DAL;

namespace BLL
{
    
    public class TIBLL
    {
        TIDAL dal = new TIDAL();
        public bool Add(TIModel rm)//插入数据
        {
            if (dal.InsterTI(rm) > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        public bool Delete()//删除数据
        {
            if (dal.Delete() > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        public DataTable Read()
        {
            return dal.Read();
 
        }
    }

  
}

5.UI层类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace UI
{
    interface Iation//定义计算接口
    {
        double Calation(double a, double b);
    }
    class Add : Iation//加法
    {
        public double Calation(double a, double b)
        {
            return a + b;
        }
    }
    class Sub : Iation//减法
    {
        public double Calation(double a, double b)
        {
            return a - b;
        }
    }
    class Mul : Iation//乘法
    {
        public double Calation(double a, double b)
        {
            return a * b;
        }
    }
    class Div : Iation//除法
    {
        public double Calation(double a, double b)
        {
            if (b == 0)
            {
                throw new Exception("除数不能为零！");
            }
            else
            {
                return a / b;
            }
        }
    }
    class Factionsss//实现策略模式！
    {
        private Iation clation;
        public Factionsss(string operation)
        {
            switch (operation)
            {
                case "+":
                    clation = new Add();
                    break;
                case "-":
                    clation = new Sub();
                    break;
                case "*":
                    clation = new Mul();
                    break;
                case "/":
                    clation = new Div();
                    break;
            }

        }
        public double cal(double a, double b)
        {
            return clation.Calation(a, b);
        }

    }
    class Calculate
    { 
        
        public double Result(double a,string operation1,double b,string operation2,double c,string operation3,double d)
        {

            double answer = 0;
           
            if (operation2 == "+" || operation2 == "-")
            {
                bool leftPriority;
                if (operation1 == "*" || operation1 == "/")
                {
                    leftPriority = true;
                }
                else if (operation3 == "*" || operation3 == "/")
                {
                    leftPriority = false;
                }
                else
                {
                    leftPriority = true;
                }
                if (leftPriority == true)
                {
                    Factionsss faction = new Factionsss(operation1);
                    double answer1 = faction.cal(a, b);
                    faction = new Factionsss(operation2);
                    double answer2 = faction.cal(answer1, c);
                    faction = new Factionsss(operation3);
                    answer = faction.cal(answer2, d);

                }
                else
                {
                    Factionsss faction = new Factionsss(operation3);
                    double answer1 = faction.cal(c, d);
                    faction = new Factionsss(operation2);
                    double answer2 = faction.cal(b, answer1);
                    faction = new Factionsss(operation1);
                    answer = faction.cal(a, answer2);
 
                }
              
            }
            if (operation2 == "*" || operation2 == "/")
            {
                bool leftPriority;
                if (operation1 == "*" || operation1 == "/")
                {
                    leftPriority = true;
                }
                else if (operation3 == "*" || operation3 == "/")
                {
                    leftPriority = false;
                }
                else
                {
                    leftPriority = false;
                }
                if (leftPriority == true)
                {
                    Factionsss faction = new Factionsss(operation1);
                    double answer1 = faction.cal(a, b);
                    faction = new Factionsss(operation2);
                    double answer2 = faction.cal(answer1, c);
                    faction = new Factionsss(operation3);
                    answer = faction.cal(answer2, d);

                }
                else
                {
                    Factionsss faction = new Factionsss(operation2);
                    double answer1 = faction.cal(b, c);
                    faction = new Factionsss(operation3);
                    double answer2 = faction.cal(answer1, d);
                    faction = new Factionsss(operation1);
                    answer = faction.cal(answer2, a);
                }
 
            }

            return answer;
        }
    }
   
}

form1代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Model;
using BLL;


namespace UI
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        TIBLL bll = new TIBLL();
        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)//开始
        {
            TIModel rm = new TIModel();
            rm.Number1 = textBox1.Text;
            rm.Number2 = textBox2.Text;
            rm.Number3 = textBox3.Text;
            rm.Number4 = textBox4.Text;
            rm.Operation1 = comboBox1.Text;
            rm.Operation2 = comboBox2.Text;
            rm.Operation3 = comboBox3.Text;
            if (bll.Add(rm) == true)
            {
                MessageBox.Show("保存成功!");

            }
            else
            {
                MessageBox.Show("插入失败！");
            }
            textBox1.Clear();
            textBox2.Clear();
            textBox3.Clear();
            textBox4.Clear();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (bll.Delete() == true)
            {
                MessageBox.Show("删除失败！");
            }
            else
            {
                MessageBox.Show("删除成功！");
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Form2 fas = new Form2();
            fas.ShowDialog();
        }
       
    }
}

form2代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using Model;
using BLL;

namespace UI
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        TIBLL bll = new TIBLL(); 
        int i=0;
        private void Form2_Load(object sender, EventArgs e)
        {
            Reading();

        }

        private void button1_Click(object sender, EventArgs e)
        {
            Reading();
        }
        private void Reading()
        {
           
            DataTable dt = bll.Read();
            textBox1.Text = dt.Rows[i][0].ToString().Trim();
            label1.Text = dt.Rows[i][1].ToString().Trim();
            textBox2.Text = dt.Rows[i][2].ToString().Trim();
            label2.Text = dt.Rows[i][3].ToString().Trim();
            textBox3.Text = dt.Rows[i][4].ToString().Trim();
            label3.Text = dt.Rows[i][5].ToString().Trim();
            textBox4.Text = dt.Rows[i][6].ToString().Trim();
            i++;
            if (i == dt.Rows.Count - 1)
            {
                MessageBox.Show("你做完了！");
            }
          
        }

        private void textBox5_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                Calculate calcuate = new Calculate();
                double a=double.Parse(textBox1.Text);
                double b=double.Parse(textBox2.Text);
                double c=double.Parse(textBox3.Text);
                double d=double.Parse(textBox4.Text);
                string operation1=label1.Text;
                string operation2=label2.Text;
                string operation3=label3.Text;
                double answer = calcuate.Result(a, operation1, b, operation2, c, operation3, d);
                if (textBox5.Text == answer.ToString())
                {
                    MessageBox.Show("回答正确！");
                }
                else
                {
                    MessageBox.Show("回答错误！");
                }
                textBox5.Clear();
                Reading();

            }
        }
    }
}

 6,数据库存题测试

7,总结

一开始真的不懂怎么去实现程序集下的三层架构，直到现在依然感觉掌握的很灵活，还有就是四个数的运算，老师让去掉工厂模式，但是去掉工厂模式代码的编写会更加的麻烦，所以就没有去掉工厂模式，但是总感觉这样写程序的性能会大幅度降低，还有就是计算类的存放问题，应该放到哪一个层里面搞不明白，本来想放在业务逻辑层的，但是最终还是放在了UI层！