使用gui创建一个窗口：
public class TestApp { public static void main(String[] args) { EventQueue.invokeLater(() -> { JFrame frame = new JFrame("Welcome"); frame.setSize(500, 500); frame.setResizable(false); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); }); } }创建一个窗口和面板：
public class AlgoFrame extends JFrame{ private int canvasWidth; private int canvasHeight; public AlgoFrame(String title, int canvasWidth, int canvasHeight){ super(title); this.canvasWidth = canvasWidth; this.canvasHeight = canvasHeight; //setSize(canvasWidth, canvasHeight); AlgoCanvas canvas = new AlgoCanvas(); // canvas.setPreferredSize(new Dimension(canvasWidth,canvasHeight)); setContentPane(canvas); pack(); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setResizable(false); setVisible(true); // System.out.println(getContentPane().getBounds()); } public AlgoFrame(String title){ this(title, 1024, 768); } private class AlgoCanvas extends JPanel{ @Override public void paintComponent(Graphics g) { super.paintComponent(g); g.drawOval(50, 50, 300, 300); } @Override public Dimension getPreferredSize(){ return new Dimension(canvasWidth, canvasHeight); } } } Graphics2D 进行画图操作： private class AlgoCanvas extends JPanel { @Override public void paintComponent(Graphics g) { super.paintComponent(g); // g.drawOval(50, 50, 300, 300); Graphics2D g2d = (Graphics2D) g; int strokeWidth = 5; g2d.setStroke(new BasicStroke(strokeWidth, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));//设置线条宽度 g2d.setColor(Color.RED);//设置颜色，直到下次颜色改变 Ellipse2D circle = new Ellipse2D.Double(50, 50, 300, 300); g2d.draw(circle); g2d.setColor(Color.BLUE); Ellipse2D circle2 = new Ellipse2D.Double(50, 50, 300, 300); g2d.fill(circle2); }
通过指定圆心、半径来绘制圆形：
public class AlgoVisHelper { private AlgoVisHelper() { } public static void strokeCircle(Graphics2D g, int x, int y, int r) { Ellipse2D circle = new Ellipse2D.Double(x - r, y - r, 2 * r, 2 * r); g.draw(circle); } public static void fillCircle(Graphics2D g, int x, int y, int r) { Ellipse2D circle = new Ellipse2D.Double(x - r, y - r, 2 * r, 2 * r); g.fill(circle); } public static void setColor(Graphics2D g, Color color) { g.setColor(color); } public static void setStrokeWidth(Graphics2D g, int w) { int strokeWidth = w; /** * 第一个参数：线条宽度 * 第二个参数：线条末端的形状 原点 * 第三个参数：折点的形状 平滑的圆形 */ g.setStroke(new BasicStroke(strokeWidth, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND)); } }
private class AlgoCanvas extends JPanel { @Override public void paintComponent(Graphics g) { super.paintComponent(g); // g.drawOval(50, 50, 300, 300); Graphics2D g2d = (Graphics2D) g; // 抗锯齿 RenderingHints hints = new RenderingHints( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g2d.addRenderingHints(hints); // 具体绘制 AlgoVisHelper.setColor(g2d, Color.BLUE); AlgoVisHelper.fillCircle(g2d, width/2,height/2,200); AlgoVisHelper.setStrokeWidth(g2d,5); AlgoVisHelper.setColor(g2d, Color.RED); AlgoVisHelper.strokeCircle(g2d, width/2,height/2,200); } ｝
public AlgoCanvas(){ // 双缓存 super(true); }圆圈类： public class Circle { public int x; public int y; private int r; public int vx; public int vy; public Circle(int x, int y, int r, int vx, int vy) { this.x = x; this.y = y; this.r = r; this.vx = vx; this.vy = vy; } public int getR() { return r; } public void move(int minx, int miny, int maxx, int maxy) { x += vx; y += vy; checkCollision(minx, miny, maxx, maxy); } private void checkCollision(int minx, int miny, int maxx, int maxy) { if (x - r < minx) { x = r; vx = -vx; } if (x + r >= maxx) { x = maxx - r; vx = -vx; } if (y - r < miny) { y = r; vy = -vy; } if (y + r >= maxy) { y = maxy - r; vy = -vy; } } } 进行绘制： public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2d = (Graphics2D)g; // 抗锯齿 RenderingHints hints = new RenderingHints( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); hints.put(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY); g2d.addRenderingHints(hints); // 具体绘制 AlgoVisHelper.setStrokeWidth(g2d,1); AlgoVisHelper.setColor(g2d, Color.RED); for(Circle circle: circles) AlgoVisHelper.strokeCircle(g2d, circle.x, circle.y, circle.getR()); }
mvc在算法中的体现：
public class AlgoVisualizer { private Circle[] circles; // 数据 private AlgoFrame frame; // 视图 public AlgoVisualizer(int sceneWidth, int sceneHeight, int N) { // 初始化数据 circles = new Circle[N]; int R = 50; for (int i = 0; i < N; i++) { int x = (int) (Math.random() * (sceneWidth - 2 * R)) + R; int y = (int) (Math.random() * (sceneHeight - 2 * R)) + R; int vx = (int) (Math.random() * 11) - 5; int vy = (int) (Math.random() * 11) - 5; circles[i] = new Circle(x, y, R, vx, vy); } // 初始化视图 EventQueue.invokeLater(() -> { frame = new AlgoFrame("Welcome", sceneWidth, sceneHeight); new Thread(() -> { run(); }).start(); }); } // 动画逻辑 private void run() { while (true) { // 绘制数据 frame.render(circles); AlgoVisHelper.pause(20); // 更新数据 for (Circle circle : circles) circle.move(0, 0, frame.getWidth(), frame.getHeight()); } } } public static void main(String[] args) { int sceneWidth = 800; int sceneHeight = 800; // init data int N = 10; AlgoVisualizer algoVisualizer = new AlgoVisualizer(sceneWidth, sceneHeight, N); }
gui中的键盘事件：
public class AlgoVisualizer { private Circle[] circles; private AlgoFrame frame; private boolean isAnimated = true; public AlgoVisualizer(int sceneWidth, int sceneHeight, int N) { // 初始化数据 circles = new Circle[N]; int R = 50; for (int i = 0; i < N; i++) { int x = (int) (Math.random() * (sceneWidth - 2 * R)) + R; int y = (int) (Math.random() * (sceneHeight - 2 * R)) + R; int vx = (int) (Math.random() * 11) - 5; int vy = (int) (Math.random() * 11) - 5; circles[i] = new Circle(x, y, R, vx, vy); } // 初始化视图 EventQueue.invokeLater(() -> { frame = new AlgoFrame("Welcome", sceneWidth, sceneHeight); frame.addKeyListener(new AlgoKeyListener()); new Thread(() -> { run(); }).start(); }); } public void run() { while (true) { // 绘制数据 frame.render(circles); AlgoVisHelper.pause(20); // 更新数据 if (isAnimated) for (Circle circle : circles) circle.move(0, 0, frame.getWidth(), frame.getHeight()); } } private class AlgoKeyListener extends KeyAdapter { @Override public void keyReleased(KeyEvent event) { if (event.getKeyChar() == ' ') isAnimated = !isAnimated; } } public static void main(String[] args) { int sceneWidth = 800; int sceneHeight = 800; int N = 10; AlgoVisualizer vis = new AlgoVisualizer(sceneWidth, sceneHeight, N); } }
gui中鼠标事件：
public class AlgoVisualizer { private Circle[] circles; private AlgoFrame frame; private boolean isAnimated = true; public AlgoVisualizer(int sceneWidth, int sceneHeight, int N){ // 初始化数据 circles = new Circle[N]; int R = 50; for(int i = 0 ; i < N ; i ++){ int x = (int)(Math.random()*(sceneWidth-2*R)) + R; int y = (int)(Math.random()*(sceneHeight-2*R)) + R; int vx = (int)(Math.random()*11) - 5; int vy = (int)(Math.random()*11) - 5; circles[i] = new Circle(x, y, R, vx, vy); } // 初始化视图 EventQueue.invokeLater(() -> { frame = new AlgoFrame("Welcome", sceneWidth, sceneHeight); frame.addKeyListener(new AlgoKeyListener()); frame.addMouseListener(new AlgoMouseListener()); new Thread(() -> { run(); }).start(); }); } // 动画逻辑 private void run(){ while(true){ // 绘制数据 frame.render(circles); AlgoVisHelper.pause(20); // 更新数据 if(isAnimated) for(Circle circle : circles) circle.move(0, 0, frame.getCanvasWidth(), frame.getCanvasHeight()); } } private class AlgoKeyListener extends KeyAdapter{ @Override public void keyReleased(KeyEvent event){ if(event.getKeyChar() == ' ') isAnimated = !isAnimated; } } private class AlgoMouseListener extends MouseAdapter{ @Override public void mousePressed(MouseEvent event){ //System.out.println(event.getPoint()); event.translatePoint(0, -(frame.getBounds().height - frame.getCanvasHeight())); for(Circle circle : circles) if(circle.contain(event.getPoint())) circle.isFilled = !circle.isFilled; } } public static void main(String[] args) { int sceneWidth = 800; int sceneHeight = 800; int N = 10; AlgoVisualizer visualizer = new AlgoVisualizer(sceneWidth, sceneHeight, N); } }
转载于:https://www.cnblogs.com/lzb0803/p/9033748.html
