Question

class MainCanvas extends Canvas implements Runnable, MouseListener {
    Color rgbcolor;
    int x;
    int y;
    int dx;
    int dy;
    Thread t;
    BufferedImage bimage = new BufferedImage(300, 300, BufferedImage.TYPE_INT_RGB);
    Graphics g2;
    MainCanvas(){
        setBackground(Color.WHITE);
        addMouseListener(this);

        t=new Thread(this, "mythread");
        t.start();
    }
    public void paint(Graphics g){
        g2 = bimage.createGraphics();
        g2.drawImage(bimage, 0, 0, 30, 300, null);
        g2.setColor(rgbcolor);
        g2.drawLine(x, y, dx, dy);
        g2.dispose();
    }
    public void update(Graphics g){
        g2 = bimage.createGraphics();
        g2.drawImage(bimage, 0, 0, 30, 300, null);
        g2.setColor(rgbcolor);
        g2.drawLine(x, y, dx, dy);
        g2.dispose();
    }
    public void setRGBColor(Color rgbcolor){
        this.rgbcolor=rgbcolor;
    }
    @Override
    public void mouseClicked(MouseEvent arg0) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseEntered(MouseEvent arg0) {
        // TODO Auto-generated method stub

    }
    @Override
    public void mouseExited(MouseEvent arg0) {
        // TODO Auto-generated method stub

    }
    @Override
    public void mousePressed(MouseEvent arg0) {
        // TODO Auto-generated method stub
        x=arg0.getX();
        y=arg0.getY();
        dx=arg0.getX();
        dy=arg0.getY();
        System.out.println("mouse pressed");
    }
    @Override
    public void mouseReleased(MouseEvent arg0) {
        // TODO Auto-generated method stub
        dx=arg0.getX();
        dy=arg0.getY();
        System.out.println("mouse released");
    }
    @Override
    public void run() {
        // TODO Auto-generated method stub
        while(true){
            try {
                Thread.currentThread();
                Thread.sleep(300);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            repaint();
        }
    }
}

我不确定为什么它不能正常工作，我能做的最好就是在图像后面画画。我基本上只是试图绘制图像。我尝试了几种不同的方法，而不是g = bimage.getGraphics().setColor()，但我知道有更好的方法。

Answer 1

我正在绘制我的图像，但是之后没有将它画到画布上。我需要做的是用图形Graphics2D g2绘制到我的bufferedImage，然后使用Graphics g绘制/绘制图像。

Graphics2D g2 = bimage.createGraphics();
    g2.setColor(rgbcolor);
    g2.fillRect(x, y, dx, dy);
    g2.dispose();
    g.drawImage((Image)bimage,0,0,100,100,null);

缓冲图像策略不起作用，

1 个答案: