(深入.Net平台和C#编程)第六章.简答题5.20170410

-------------------------------------------父类形状类-------------------------------------------

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Drawing;
 4 using System.Linq;
 5 using System.Text;
 6 using System.Threading.Tasks;
 7 
 8 namespace J4.entity
 9 {
10     public class Shape
11     {
12         public virtual void Draw(Graphics g, Pen p)
13         {
14         }
15     }
16 }

Shape

-------------------------------------------子类圆形类-------------------------------------------

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Drawing;
 4 using System.Linq;
 5 using System.Text;
 6 using System.Threading.Tasks;
 7 
 8 namespace J4.entity
 9 {
10     public class Circle:Shape
11     {
12         public override void Draw(Graphics g, Pen p)
13         {
14             g.DrawEllipse(p, 75,150,100,100);
15         }
16 
17       
18     }
19 }

Circle

-------------------------------------------子类矩形类-------------------------------------------

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Drawing;
 4 using System.Linq;
 5 using System.Text;
 6 using System.Threading.Tasks;
 7 
 8 namespace J4.entity
 9 {
10    public class Rect:Shape
11     {
12        public override void Draw(Graphics g, Pen p)
13        {
14            Rectangle rec = new Rectangle(20, 100, 200, 200);
15            g.DrawRectangle(p, rec);
16        }
17     }
18 }

Rect

-------------------------------------------主窗体类-------------------------------------------

 1 using J4.entity;
 2 using System;
 3 using System.Collections.Generic;
 4 using System.ComponentModel;
 5 using System.Data;
 6 using System.Drawing;
 7 using System.Linq;
 8 using System.Text;
 9 using System.Threading.Tasks;
10 using System.Windows.Forms;
11 
12 namespace J4
13 {
14     public partial class frmMain : Form
15     {
16         public frmMain()
17         {
18             InitializeComponent();
19         }
20 
21         private void btnDraw_Click(object sender, EventArgs e)
22         {
23             //Graphics g = CreateGraphics();
24             ////(颜色,厚度)
25             //Pen p = new Pen(Color.Red,3);
26             ////(X轴坐标,Y轴坐标,宽,高)
27             //Rectangle rec = new Rectangle(50,100,200,200);
28             ////矩形
29             //g.DrawRectangle(p,rec);
30             ////圆形
31             //g.DrawEllipse(p,50,100,100,100);
32 
33 
34 
35             Shape shape = new Shape();
36             Graphics g = this.panel1.CreateGraphics();
37             //默认红色
38             Pen p = new Pen(Color.Red, 3);
39 
40             //判断选中的是什么形状
41             if (rbtnCircle.Checked == true)
42             {
43                 shape = new Circle();
44             }
45             else
46             {
47                 shape = new Rect();
48             }
49             //判断选中的是什么颜色
50             if (rbtnBlue.Checked == true)
51             {
52                 p = new Pen(Color.Blue, 3);
53             }
54             else if (rbtnYellow.Checked == true)
55             {
56                 p = new Pen(Color.Yellow, 3);
57             }
58             //调用方法
59             shape.Draw(g,p);
60             
61         }
62 
63         private void panel1_Paint(object sender, PaintEventArgs e)
64         {
65         }
66     }
67 }

frmMain