java - 如何向JComponent添加多个对象？

Question

这是我的测试人员类(class):

public void start() {
    // We do our drawing here       
    JFrame frame = new JFrame("Animation");
    frame.setSize(800, 600);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    frame.add(new Shape1(getRandom(WIDTH), getRandom(HEIGHT), objRadius));
    frame.add(new Shape1(getRandom(WIDTH), getRandom(HEIGHT), objRadius));
    frame.add(new Shape1(getRandom(WIDTH), getRandom(HEIGHT), objRadius));


    frame.setVisible(true);
}

Shape1 类:

public class Shape1 extends JComponent{
    protected double x, y, r;
    protected double height, width;
    protected Color col;
    protected int counter;

    public Shape1(double x, double y, double r) {
        this.x = x - 2*r;
        this.y = y - r;
        this.r = r;
        this.width = 4*r;
        this.height = 2*r;

        this.col = new Color((int)(Math.random() * 0x1000000));
    }

    public void paintComponent(Graphics g){
        Graphics2D g2 = (Graphics2D)g;
        draw(g2);
    }

    public void draw(Graphics2D g2){
        Ellipse2D.Double face = new Ellipse2D.Double(this.x, this.y, this.width, this.height);

        g2.setColor(this.col);
        g2.fill(face);
    }
}

我实例化 Shape1 类 3 次并将它们添加到框架中。但是形状只画了一次，怎么画3次呢？

Answer 1

您可以尝试使用循环:

List<Shape1> shapes = new ArrayList<>();

@Override
protected void paintComponent(Graphics g) {
    super.paintCompoent(g);
    for (Shape1 s : shapes) {
        s.draw(g);
    }
}