这里是例子。为了测试它,你需要用你的背景图像替换我的图像。
import java.awt.AlphaComposite;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;
/**
* <code>PaintTryout</code>.
*
* @author smedvynskyy
*/
public class PaintPanel extends JPanel {
private Image backgroundImage;
private BufferedImage paintImage;
public PaintPanel() {
try {
// replace this image with your image
backgroundImage = ImageIO.read(new File("E:\\icons\\blackboard.png"));
paintImage = new BufferedImage(backgroundImage.getWidth(this),
backgroundImage.getHeight(this), BufferedImage.TYPE_INT_ARGB);
} catch (final Exception e) {
e.printStackTrace();
}
}
public void fillRect() {
final Graphics g = paintImage.createGraphics();
g.setColor(Color.RED);
g.fillRect(0, 0, 50, 50);
g.dispose();
repaint();
}
public void clearRect() {
final Graphics2D g = paintImage.createGraphics();
g.setColor(new Color(0, 0, 0, 0));
g.setComposite(AlphaComposite.Clear); // overpaint
g.fillRect(0, 0, 50, 50);
g.dispose();
repaint();
}
/**
* {@inheritDoc}
*/
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(backgroundImage, 0, 0, this);
g.drawImage(paintImage, 0, 0, this);
}
/**
* {@inheritDoc}
*/
@Override
public Dimension getPreferredSize() {
return new Dimension(backgroundImage.getWidth(this),
backgroundImage.getHeight(this));
}
public static void main(String[] args) {
final JFrame frm = new JFrame("Tesp paint");
final PaintPanel p = new PaintPanel();
frm.add(p);
final JPanel buttons = new JPanel();
final JButton fill = new JButton("Fill Rect");
fill.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
p.fillRect();
}
});
final JButton clear = new JButton("Clear Rect");
clear.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
p.clearRect();
}
});
buttons.add(fill);
buttons.add(clear);
frm.add(buttons, BorderLayout.SOUTH);
frm.pack();
frm.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frm.setLocationRelativeTo(null);
frm.setVisible(true);
}
}
我想你想在你的图形2d –
上做任何其他事情之前打电话给g.drawImage(XXX)是的,我已经在做它了。但问题仍然存在 –
您需要将2幅图像叠加在一起。首先是你的源图像。其次是你的线条/形状的图像。如果你想删除一些东西,你需要在你的第二张图片上填充一个不透明的颜色。 –