方法没有给出想要的结果？

Question

我有这个程序应该是“draw”米老鼠脸：

import java.awt.Canvas;
import java.awt.Graphics;
import javax.swing.JFrame;
import java.awt.Rectangle;

public class Mickey extends Canvas {
    public static void main(String[] args) {
        JFrame frame = new JFrame();
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        Canvas canvas = new Mickey();
        canvas.setSize(900, 500);    

        frame.getContentPane().add(canvas);
        frame.pack();
        frame.setVisible(true);
    }
    public void mickey(Graphics g) {
        Rectangle bb = new Rectangle(400, 400, 100, 100);
        boxOval(g, bb);

        int dx = bb.width/2;
        int dy = bb.height/2;

        Rectangle half = new Rectangle(bb.x, bb.y, dx, dy);

        half.translate(-dx/2, -dy/2);
        boxOval(g, half);

        half.translate(dx*2, 0);
        boxOval(g, half);
    }
    public void boxOval(Graphics g, Rectangle bb) {
        g.fillOval(bb.x, bb.y, bb.width, bb.height);
    }    
}

程序什么都不显示，一片空白，有什么问题吗？

Answer 1

您应该按照 javadoc

中的描述覆盖 paint() 方法

An application must subclass the Canvas class in order to get useful functionality such as creating a custom component. The paint method must be overridden in order to perform custom graphics on the canvas.

所以在这里简单地尝试将您的方法 public void mickey(Graphics g) 重命名为 public void paint(Graphics g)。

方法没有给出想要的结果？

methods not giving wanted result?

java

graphics

awt