Calculator.cs
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 /// <summary> 6 ///Calculator 的摘要说明 7 /// </summary> 8 public abstract class Calculator 9 { 10 public abstract double Cal(double x, double y); 11 } 12 13 public class Add : Calculator //接口法运算 14 { 15 public override double Cal(double x, double y) //重写 16 { 17 double result = 0; 18 result = x + y; 19 return result; 20 } 21 } 22 public class Sub : Calculator 23 { 24 public override double Cal(double x, double y) 25 { 26 double result = 0; 27 result = x - y; 28 return result; 29 } 30 } 31 public class Mul : Calculator 32 { 33 public override double Cal(double x, double y) 34 { 35 double result = 0; 36 result = x * y; 37 return result; 38 } 39 } 40 public class Div : Calculator 41 { 42 public override double Cal(double x, double y) 43 { 44 double result = 0; 45 result = x / y; 46 return result; 47 } 48 } 49 public class Opear //定义运算符 50 { 51 private Calculator calculate = null; //实例化一个基类的引用对象 52 public Opear(Calculator calculator) //calculator为派生类的一个对象 53 { 54 this.calculate = calculator; //把派生类的对象赋给基类的引用对象 55 } 56 public double Cal(double x, double y, String op) 57 { 58 return this.calculate.Cal(x, y); //返回计算结果 59 } 60 }
ASP.net后台代码：
1 using System; 2 using System.Collections.Generic; 3 using System.Linq; 4 using System.Web; 5 using System.Web.UI; 6 using System.Web.UI.WebControls; 7 public partial class Default2 : System.Web.UI.Page 8 { 9 protected void Page_Load(object sender, EventArgs e) 10 { 11 12 } 13 protected void Button1_Click(object sender, EventArgs e) 14 { 15 string op = DropDownList1.SelectedItem.ToString(); 16 double x = Convert.ToDouble(TextBox1.Text); 17 double y = Convert.ToDouble(TextBox2.Text); 18 19 Opear opear =null; 20 if (DropDownList1.SelectedIndex == 0) 21 { 22 opear = new Opear(new Add()); 23 } 24 else if (DropDownList1.SelectedIndex == 1) 25 { 26 opear = new Opear(new Sub()); 27 } 28 else if (DropDownList1.SelectedIndex == 2) 29 { 30 opear = new Opear(new Mul()); 31 } 32 else if (DropDownList1.SelectedIndex == 3) 33 { 34 opear = new Opear(new Div()); 35 } 36 string answer = opear.Cal(x, y, op).ToString(); 37 string result = TextBox1.Text + DropDownList1.SelectedItem.ToString() + TextBox2.Text; 38 if (TextBox4.Text == answer) 39 { 40 Response.Write("<script>alert('回答正确!')</script>"); 41 ListBox1.Items.Add(result + "=" + TextBox4.Text.Trim()); 42 } 43 44 else 45 { 46 Response.Write("<script>alert('答题错误!')</script>"); 47 ListBox1.Items.Add(result + "=" + TextBox4.Text.Trim()); 48 } 49 TextBox1.Text = ""; 50 TextBox2.Text = ""; 51 TextBox4.Text = ""; 52 } 53 }
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运行界面：
