简单随机

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

namespace 封装1
{
public class Calcuater
{
private int numberA;
private int numberB;
public int NumberA
{
get { return numberA; }
set {numberA=value;}
}
public int NumberB
{
get
{
return numberB;
}
set
{
numberB = value;
}
}
public virtual int getresult()
{
int result=0;
return result;
}
}
public class Add : Calcuater
{
public override int getresult()
{
int result = 0;
result = NumberA + NumberB;
return result;
}

}
public class Sub : Calcuater
{
public override int getresult()
{
int result = 0;
result = NumberA - NumberB;
return result;
}

}
public class Mul : Calcuater
{
public override int getresult()
{
int result = 0;
result = NumberA * NumberB;
return result;
}
}
public class Div : Calcuater
{
public override int getresult()
{
int result = 0;
if (NumberB == 0)
{
throw new Exception("除数不能为零！");
}
else
{
result = NumberA / NumberB;
}
return result;
}
}
}

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

namespace 封装1
{
class factory
{
public static Calcuater create(string operte)
{
Calcuater oper=null;
switch (operte)
{
case "+":
oper = new Add();
break;
case "-":
oper = new Sub();
break;
case "*":
oper = new Mul();
break;
case "/":
oper = new Div();
break;

}
return oper;
}
}
}

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;

namespace 封装1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e)
{
chuti();
}

private void textBox3_KeyDown(object sender, KeyEventArgs e)
{
int a =int.Parse( textBox1.Text);
int b = int.Parse(textBox2.Text);
string c = label1.Text;
if (e.KeyCode == Keys.Enter)
{
Calcuater calas = factory.create(c);
calas.NumberA = a;
calas.NumberB = b;
int reat = calas.getresult();
if (textBox3.Text == reat.ToString())
{
MessageBox.Show("回答正确！");
}
else
{
MessageBox.Show("回答错误！");
}
textBox3.Clear();
chuti();

}

}

private void chuti()
{
Random random = new Random();
textBox1.Text = random.Next(0, 100).ToString();
textBox2.Text = random.Next(0, 100).ToString();
string[] operte = new string[] { "+", "-", "*", "/" };
label1.Text = operte[new Random().Next(0, 4)];
}
}
}