在我的课堂上，X我扩展JPanel并实施了MouseListener，MouseMotionListener
int numPoints = 0;
Point controlPoints[] = new Point[10];
public void MousePressed (MouseEvent arg0) {
if (numPoints < 5)
controlPoints[numPoints] = arg0.getPoint();
numPoints++;
}
*当我 System.out.println(numPoints); *
3 CLICKS 后输出；
- 0
- 0
- 2
- 2
- 3
- 3
- 5
为什么它不增加 1, 2 ,3 ???
输出（对于 numPoints）（第一次鼠标点击）
- 1
- 2
***如有必要，我将提供更多信息。
感谢您的回复。这是完整编辑的javacode。这个问题对我来说仍然没有解决。我期待新的想法和更正。提前致谢
package work2014.java.all;
java.awt.*;
import java.awt.event.*
import java.util.ArrayList;
import javax.swing.*;
class jdrawPanel extends JPanel implements MouseListener, MouseMotionListener, ActionListener
{
Graphics g;
boolean paint = false, edit = false;
Point d;
Point curvePoints[]= new Point[100];
Point[] controlPoints = new Point[99];
int n = 99, i = 3;
private int numPoints = 0;
public void paintComponent(Graphics g){
addMouseListener(this);
addMouseMotionListener(this);
super.paintComponent(g);
if(numPoints >= 0 && numPoints < controlPoints.length)
Dot(numPoints,controlPoints,g);
if(paint == true && numPoints >= 3){
drawBezier(n, i, controlPoints, g);
}
this.requestFocus();
}
public void Dot(int numPoints, Point controlPoints[], Graphics g){
draw red dot
}
public void drawBezier(int n, int i, Point controlPoints[], Graphics g)
{
draw spline
} // End drawBezier
@Override
public void mouseMoved(MouseEvent arg0) {
Point p = arg0.getPoint();
if (equalPoint(p) == p)
setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
else
setCursor(Cursor.getDefaultCursor());
}
@Override
public void mousePressed(MouseEvent arg0) {
paint = true;
Point d = arg0.getPoint();
if(numPoints <= 10) {
controlPoints[numPoints] = d;
numPoints++;
System.out.println(numPoints);
}
repaint();
}
}
class Oving5_Frame extends JFrame
{ public Oving5_Frame()
{ setTitle("Hello draW v2");
setSize(600, 600);
addWindowListener(new WindowAdapter()
{ public void windowClosing(WindowEvent e)
{ System.exit(0);
}
} );
Container contentPane = getContentPane();
contentPane.setLayout(new BorderLayout());
contentPane.add(new jdrawPanel, BorderLayout.CENTER);
contentPane.add(class_menu(), BorderLayout.NORTH);
}
public class Oving5_launch
{
public static void main(String[] args)
{
JFrame frame = new Oving5_Frame();
frame.show();
}
}