C# GUI弹球动画

学习慕课的资源来源：
​​​ https://www.icourse163.org/spoc/learn/GZU-1455988161​​ 创建一个弹球类：Ball.cs文件里

using System;
using System.Drawing;

namespace fallingBall
{
    public enum ballState
    {
        Continue,
        catchBall,
        loseBall
    }
    public class Ball
    {
        private const int rectWidth = 300;
        private const int rectHight = 600;

        private const int radius = 20;

        private int boardWidth = 40;
        private int boardHeight = 10;

        private int ballX = 0;
        private int ballY = 0;

        private int boardX = 0;
        private int boardY;

        private int downStep;
        public Ball()
        {
            boardY = rectHight - boardHeight;
            downStep = 10;
        }
        public Ball(int dstep)
        {
            downStep = dstep;
            boardY = rectHight - boardHeight;
        }
        public int BallX {
            set {
                if (value < 0) ballX = 0;
                else if (value > rectWidth - 2 * radius) ballX = rectWidth - 2 * radius;
                else
                    ballX = value;
            }
            get { return ballX; }
        }
        public int BallY
        {
            set
            {
                if (value < 0) ballY = 0;
                else if (value > rectHight - 2 * radius) ballY = rectHight - 2 * radius;
                else ballY = value;
            }
            get { return ballY; }
        }
        public int BoardX
        {
            get { return boardX; }
            set
            {
                if (value < 0) boardX = 0;
                else if (value > rectWidth - boardWidth) boardX = rectWidth - boardWidth;
                else
                    boardX = value;
            }
        }
        public int BoardY
        {
            get { return boardY; }
            set { boardY = value; }
        }  
        public int Radius {  get {return radius; } }
        public int BoardWidth { get { return boardWidth; } }
        public int BoardHeight { get { return boardHeight; } }
        public ballState Judge()
        {
            if (BallY + 2 * radius < rectHight)// - boardHeight ) 
                return ballState.Continue;
            else 
            {
                if (BallX + radius >= BoardX  &&  BallX + radius <= BoardX + boardWidth ) 
                    return ballState.catchBall;
                else
                    return ballState.loseBall;
            }

        }
        public void NewGame()
        {
            Random r = new Random();
            ballX = r.Next(0,rectWidth-2*radius);
            ballY = 0;
        }
        public Rectangle GetRectangle()
        {
            return new Rectangle(0, 0, rectWidth, rectHight);
        }
        public int DownStep { get { return downStep; }  }
    }
}

Form1.cs文件内容：（我们需要点击Form1.cs[设计]的Time控件（在属性中设置毫秒数）、鼠标点击事件keydown、paint事件,draw事件， 以及点击属性，我觉得有点像去年学的mfc，不过感觉C#友好多了）

增加事件，根据Form1.cs里文件的事件配置对应的事件

using fallingBall;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace 第12章测试习题
{
    public partial class Form1 : Form
    {
        Ball ball = new Ball();
        private int leftX = 50;
        private int leftY = 50;
        public Form1()
        {
            InitializeComponent();
            Width = 400;
            Height = 800;
            ball.NewGame();
            timer1.Enabled = true;
        }   
        private void Form1_Load(object sender, EventArgs e)
        {
            
        }
        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            SolidBrush blueBrush = new SolidBrush(Color.Blue);
            Graphics g = e.Graphics;
            Rectangle gameRect = new Rectangle(leftX, leftY,
                                                ball.GetRectangle().Width, 
                                                ball.GetRectangle().Height);//50 50 300 600
            g.FillRectangle(blueBrush, gameRect);

            SolidBrush whiteBrush = new SolidBrush(Color.White);
            Rectangle ballRectangle = new Rectangle(leftX + ball.BallX,//50+X
                                                    leftY + ball.BallY, //50
                                                    2 * ball.Radius, //40
                                                    2 * ball.Radius);//40
            g.FillEllipse(whiteBrush, ballRectangle);

            SolidBrush redBrush = new SolidBrush(Color.Red);
            Rectangle boardRect = new Rectangle(
                                    leftX+ball.BoardX,//500
                                    leftY+ball.BoardY,//50+(rectHight - boardHeight)即50+(600-10)
                                    ball.BoardWidth,//40
                                   ball.BoardHeight);//10
            g.FillRectangle(redBrush, boardRect);
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            ball.BallY += ball.DownStep;
            Invalidate();
            if (ball.Judge() == ballState.catchBall)
            {
                ball.NewGame();
                Invalidate();
            }
            if(ball.Judge() == ballState.loseBall)
            {
                timer1.Enabled = false;
                MessageBox.Show("GameOver!!");
                 System.Environment.Exit(0);    //这是最彻底的退出方式，不管什么线程都被强制退出，把程序结束的很干净。 参数0：代表程序正常退出；参数1：代表程序非正常退出。
            }            
            
        }

        private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            if(e.KeyCode == Keys.Left)
            {
                ball.BoardX -= 10;
            }
            if(e.KeyCode == Keys.Right)
            {
                ball.BoardX += 10;
            }
            Invalidate();
        }
    }
}

拓展：