计算器软件的代码实现 （策略模式）

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

namespace shuxuefudao
{
class qita
{

public void qingkong()
{
File.WriteAllText("writer.txt", string.Empty);
File.WriteAllText("writer1.txt", string.Empty);
File.WriteAllText("writer2.txt", string.Empty);
}
}
public interface Calculator //声明一个计算的接口
{
double Cal(double a,double  b);
}
public class Add : Calculator   //接口实现加法运算
{
public double Cal(double a, double b)
{
double result = 0;
result = a + b;
return result;
}
}
public class Sub : Calculator //接口实现减法运算
{
public double Cal(double a, double b)
{
double result = 0;
result = a - b;
return result;
}
}
public class Mul : Calculator  //接口实现乘法运算
{
public double Cal(double a, double b)
{
double result = 0;
result = a * b;
return result;
}
}
public class Div : Calculator  //接口实现除法运算
{
public  double Cal(double a, double b)
{
double result = 0;
result = a / b;
return result;
}
}
public class  Environment        //定义那个需要动态改变算法的对象
{
private Calculator calculate;
public Environment(Calculator calculate)
{
this.calculate = calculate;
}
public double Cal(double a, double b, String m) //返回运算结果
{
return this.calculate.Cal(a, b);
}
}
}

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 System.IO;

namespace shuxuefudao
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
string path = "E:\rtf";
public static int Count = 0; // 题目出的数量
public static int zuode = 0; //做的题目数量
public static int zhengque = 0;
public static int lefttime;
public static int time;
public static int sum;
int i =0;
private void Form1_Load(object sender, EventArgs e)
{

}
private void open_Click(object sender, EventArgs e) //打开文件的方法
{
OpenFileDialog TxTOpenDialog = new OpenFileDialog();
TxTOpenDialog.Filter = "RTF文件(*.RTF)|*.RTF";
if (TxTOpenDialog.ShowDialog() == DialogResult.OK)
{
path = TxTOpenDialog.FileName;
this.richTextBox1.LoadFile(TxTOpenDialog.FileName, RichTextBoxStreamType.RichText);
save.Enabled = false;
open.Enabled = false;
MessageBox.Show("读取成功", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
}
}

private void save_Click(object sender, EventArgs e) //保存文件的方法
{
SaveFileDialog TxtSaveDialog = new SaveFileDialog();
TxtSaveDialog.Filter = "RTF文件(*.RTF)|*.RTF";
if (File.Exists(path))
{

this.richTextBox1.LoadFile(path, RichTextBoxStreamType.RichText);
MessageBox.Show("保存成功", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
this.richTextBox1.Clear();
save.Enabled = false;
}
else
{
if (TxtSaveDialog.ShowDialog() == DialogResult.OK)
{

this.richTextBox1.SaveFile(TxtSaveDialog.FileName, RichTextBoxStreamType.RichText);
MessageBox.Show("保存成功", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
this.richTextBox1.Clear();
save.Enabled = false;
}
}
}

private void richTextBox1_TextChanged(object sender, EventArgs e)
{
save.Enabled = true;
if (this.richTextBox1.Text == "" || this.richTextBox1.Text == null)
{
open.Enabled = true;
}
}
private void open2_Click(object sender, EventArgs e) //打开试题的方法
{
OpenFileDialog TxTOpenDialog = new OpenFileDialog();
TxTOpenDialog.Filter = "RTF文件(*.RTF)|*.RTF";
if (TxTOpenDialog.ShowDialog() == DialogResult.OK)
{
path = TxTOpenDialog.FileName;
this.richTextBox2.LoadFile(TxTOpenDialog.FileName, RichTextBoxStreamType.RichText);
save.Enabled = false;
open.Enabled = false;
MessageBox.Show("打开成功", "提示信息", MessageBoxButtons.OK, MessageBoxIcon.Asterisk);
}
}

private void daoru_Click(object sender, EventArgs e) //导入试题的方法
{
richTextBox2.Text = richTextBox1.Text;
}

private void daan1_Click(object sender, EventArgs e)
{
if (daan1.Text == "显示答案")
{
daan.PasswordChar = Convert.ToChar(0);
daan1.Text = "隐藏答案";
}
else if (daan1.Text == "隐藏答案")
{
daan.PasswordChar = '.';
daan1.Text = "显示答案";

}
}

private void kaishi_Click(object sender, EventArgs e)
{
string[] ll = new string[100];
ll = File.ReadAllLines("writer.txt");
textBox1.Text = ll[0];
string[] lli = new string[100];
lli = File.ReadAllLines("writer1.txt");
textBox2.Text = lli[0];
string[] llp = new string[100];
llp = File.ReadAllLines("writer2.txt");
textBox3.Text = llp[0];
int minute;
try
{
minute = int.Parse(this.shijian.Text);
}
catch (System.Exception ex)
{
this.shijian1.Text = "输入错误";
return;
}
lefttime = minute;
this.timer1.Interval = 1000;
this.timer1.Enabled = true;
this.timer1.Start();

}

private void timer1_Tick(object sender, EventArgs e)
{
time = Convert.ToInt32(shijian.Text);
if (lefttime <= 0)
{
timer1.Enabled = false;
MessageBox.Show("答题时间到！");
textBox4.Enabled = false;
Form2 frm2 = new Form2();
frm2.ShowDialog();
}
this.shijian1.Text = "剩余时间" + lefttime.ToString() + "秒";
lefttime--;
}

private void jieshu_Click(object sender, EventArgs e)
{
Form2 frm2 = new Form2();
frm2.ShowDialog();
}

private void button1_Click(object sender, EventArgs e) //请编辑下道题的事件
{
Count++;
ti.Text = Count.ToString();
StreamWriter writer = File.AppendText("writer.txt");
writer.WriteLine(left.Text);
writer.Close();
StreamWriter writer1 = File.AppendText("writer1.txt");
writer1.WriteLine(fuhao.Text);
writer1.Close();
StreamWriter writer2 = File.AppendText("writer2.txt");
writer2.WriteLine(right.Text);
writer2.Close();
richTextBox1.Text += left.Text + fuhao.Text + right.Text + label2.Text + "" + "\n";
left.Clear();
fuhao.Clear();
right.Clear();
}
private void textBox4_KeyDown(object sender, KeyEventArgs e)
{

try //异常处理机制，预防数组发生越界
{
Environment environment=null;
double a = Convert.ToDouble(textBox1.Text); //为相关的变量赋值
double b = Convert.ToDouble(textBox3.Text);
string m = textBox2.Text;
int result;
switch (m)
{
case "+":
environment = new Environment(new Add()); //策略模式的引用
break;
case "-":
environment = new Environment(new Sub());

break;
case "*":
environment = new Environment(new Mul());

break;
case "/":
environment = new Environment(new Div());

break;
default:
break;
}

if (e.KeyCode == Keys.Enter)
{

if (int.TryParse(textBox4.Text, out result) == false)
{
MessageBox.Show("请输入数字");
}
string answer = environment.Cal(a, b, m).ToString();
daan.Text += answer + "\r\n";
if (textBox4.Text == answer.ToString())
{
MessageBox.Show("回答正确");
zuode++;
zhengque++;
}
else
{
MessageBox.Show("回答错误");
zuode++;
}
i++;
textBox4.Clear();
string[] ll = new string[100];
ll = File.ReadAllLines("writer.txt");
textBox1.Text = ll[i];
string[] lli = new string[100];
lli = File.ReadAllLines("writer1.txt");
textBox2.Text = lli[i];
string[] llp = new string[100];
llp = File.ReadAllLines("writer2.txt");
textBox3.Text = llp[i];
}
}
catch(Exception ex)
{
Form2 frm = new Form2();
frm.ShowDialog();
}

}
private void button2_Click(object sender, EventArgs e) //清空上次编辑试题的方法
{
qita aaa = new qita();
aaa.qingkong();
}
private void button3_Click(object sender, EventArgs e) //退出程序的方法
{
Application.Exit();
}
}
}