我试图用鼠标点击绘制任何形状..但框架只显示白色背景...... 我必须使用缓冲图像，因为这只是一项任务的一部分...否则它正在工作......有人可以帮我这个吗？请...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Component.*;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Path2D;
import java.awt.image.BufferedImage;
import java.util.ArrayList;
import java.util.List;
import java.awt.event.InputEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DrawPolygon extends JFrame{
static int X, Y;
private static BufferedImage bI = new BufferedImage(500,500, BufferedImage.TYPE_INT_RGB);
public static void main(String[] args) {
new DrawPolygon();
}
public DrawPolygon() {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Test");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new PolyPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static class PolyPane extends JPanel {
private MouseHandler mouseHandler;
private Path2D currentShape;
private List<Path2D> lstPloys;
private Point lastPoint;
private Point currentPoint;
private Image img;
private boolean initialize = true;
public PolyPane() {
lstPloys = new ArrayList<>();
}
@Override
public Dimension getPreferredSize() {
return new Dimension(500, 500);
}
@Override
public void addNotify() {
super.addNotify();
addMouseListener(getMouseHandler());
addMouseMotionListener(getMouseHandler());
}
@Override
public void removeNotify() {
removeMouseListener(getMouseHandler());
removeMouseMotionListener(getMouseHandler());
super.removeNotify();
}
public MouseHandler getMouseHandler() {
if (mouseHandler == null) {
mouseHandler = new MouseHandler();
}
return mouseHandler;
}
////////////akshay
public void BoundaryFill(int x, int y, Color bColor, Color fColor){
int current = bI.getRGB(x, y);
if((current != bColor.getRGB()) && (current != fColor.getRGB())){
//bI.setRGB(x, y, fColor.getRGB());
bI.setRGB(x, y, fColor.getRGB());
repaint();
BoundaryFill(x+1, y, bColor, fColor);
BoundaryFill(x-1, y, bColor, fColor);
BoundaryFill(x, y-1, bColor, fColor);
BoundaryFill(x, y+1, bColor, fColor);
BoundaryFill(x+1, y, bColor, fColor);
BoundaryFill(x-1, y, bColor, fColor);
BoundaryFill(x, y-1, bColor, fColor);
BoundaryFill(x, y+1, bColor, fColor);
}
else
return;
}
/* @Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
if (lastPoint != null) {
g2d.setColor(Color.RED);
g2d.fillOval(lastPoint.x - 2, lastPoint.y - 2, 4, 4);
}
if (currentShape != null) {
g2d.setColor(Color.RED);
g2d.draw(currentShape);
if (lastPoint != null && currentPoint != null) {
System.out.println(lastPoint + " - " + currentPoint);
g2d.setColor(new Color(255, 0, 0, 64));
g2d.draw(new Line2D.Float(lastPoint, currentPoint));
}
}
g2d.setColor(Color.BLACK);
for (Shape shape : lstPloys) {
g2d.draw(shape);
}
g2d.dispose();
}*/
public void paint(Graphics g){
super.paint(g);
if(initialize){
img = (Image) createPolygon();
g.drawImage(img, 0, 0, null);
//g.drawI
//initialize = false;
}else{
g.drawImage((Image)bI, 0,0,null);
}
}
public BufferedImage createPolygon(){
Graphics2D g2d = bI.createGraphics();
g2d.setColor(Color.white);
g2d.fillRect(0, 0, 500, 500);
g2d.setColor(Color.black);
if (lastPoint != null) {
g2d.setColor(Color.RED);
g2d.fillOval(lastPoint.x - 2, lastPoint.y - 2, 4, 4);
}
if (currentShape != null) {
g2d.setColor(Color.RED);
g2d.draw(currentShape);
if (lastPoint != null && currentPoint != null) {
System.out.println(lastPoint + " - " + currentPoint);
g2d.setColor(new Color(255, 0, 0, 64));
g2d.draw(new Line2D.Float(lastPoint, currentPoint));
}
}
g2d.setColor(Color.BLACK);
for (Shape shape : lstPloys) {
g2d.draw(shape);
}
g2d.dispose();
return bI;
}
public class MouseHandler extends MouseAdapter {
@Override
public void mouseClicked(MouseEvent e) {
if (e.getButton() == MouseEvent.BUTTON1) {
if (e.getClickCount() == 1) {
System.out.println("first point");
Point p = e.getPoint();
lastPoint = p;
if (currentShape == null) {
currentShape = new Path2D.Float();
currentShape.moveTo(p.x, p.y);
} else {
currentShape.lineTo(p.x, p.y);
}
repaint();
} else if (e.getClickCount() == 2) {
System.out.println("closed");
currentShape.closePath();
lstPloys.add(currentShape);
currentShape = null;
lastPoint = null;
repaint();
}
else if (e.getClickCount() == 3) {
////
initialize = false;
X = e.getX();
Y = e.getY();
System.out.println("Right!!"+X+Y);
BoundaryFill(X, Y, Color.black, Color.blue);
}
}
else if (e.getButton() == MouseEvent.BUTTON3) {
if (e.getClickCount() == 1) {
System.out.println("Right!!");
}
}
}
@Override
public void mouseMoved(MouseEvent e) {
if (currentShape != null) {
currentPoint = e.getPoint();
repaint();
} else {
currentPoint = null;
}
}
}
}
}
答案 0 :(得分：1)
它可能会解决您的问题。
在else if (e.getClickCount() == 3)方法的mouseClicked()下方放置以下行，并将其从paint()方法中移除。
initialize = false;
问题在于此initialize变量在启动时设置为false。