你的问题是你的MouseLisetener。您正在侦听MainDisplayPanel，因此当您单击JPanel时，您在mousePressed方法中返回的MouseEvent#getComponent方法将返回MainDisplayPanel实例，因为这是正在被侦听的内容，而不是Resizable实例。在老鼠的帮助下。
方案包括：
创建一个MouseListener对象并将此同一对象添加到每个Resizable作为Resizable的MouseListener，或
使用您当前的设置，但将您的Resizable保存在ArrayList中，然后在mousePressed方法中遍历数组列表，以查看是否已使用componentAt(…)方法单击任何Resizable。
请注意，我必须创建自己的SSCCE才能解决此问题。在将来再次，请帮助我们，为我们做这件事，因为它符合您和我们的最佳利益，并表明您尊重我们的时间和我们的帮助。
编辑1
我的SSCCE：
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.*;
@SuppressWarnings(“serial”)
public class MainDisplayPanel extends JPanel {
private static final int RESIZABLE_COUNT = 40;
private JButton deleteButton;
private Resizable current;
private Resizable resizer;
private List resizableList = new ArrayList();
public MainDisplayPanel(LayoutManager layout) {
super(layout);
deleteButton = new JButton(“Delete”);
deleteButton.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
deleteButtonActionPerformed(e);
}
});
this.addMouseListener(new MyMouseAdapter());
this.add(deleteButton);
for (int i = 0; i < RESIZABLE_COUNT; i++) {
addResizer();
}
}
private void deleteButtonActionPerformed(ActionEvent e) {
if (current != null) {
this.remove(current);
resizableList.remove(current);
current = null;
this.revalidate();
this.repaint();
}
}
public void addResizer() {
resizer = new Resizable();
this.add(resizer);
resizableList.add(resizer);
this.revalidate();
this.repaint();
}
private class MyMouseAdapter extends MouseAdapter {
@Override
public void mousePressed(MouseEvent e) {
current = null;
Component c = getComponentAt(e.getPoint());
for (Resizable resizable : resizableList) {
if (resizable == c) {
current = resizable;
resizable.setFill(true);
} else {
resizable.setFill(false);
}
}
}
}
public static void main(String[] args) {
JFrame jframe = new JFrame();
// !! jframe.add(new MainDisplayPanel(null));
jframe.add(new MainDisplayPanel(new FlowLayout()));
jframe.setSize(new Dimension(600, 400));
jframe.setVisible(true);
jframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
@SuppressWarnings(“serial”)
class Resizable extends JPanel {
private static final int RESIZE_WIDTH = 50;
private static final int RESIZE_HEIGHT = 40;
private static final int THICKNESS = 5;
private static final Color FILL_COLOR = Color.pink;
public Resizable() {
Random rand = new Random();
// different color border so we can see that it was the clicked one that was deleted.
Color color = new Color(
rand.nextInt(255),
rand.nextInt(255),
rand.nextInt(255));
setBorder(BorderFactory.createLineBorder(color, THICKNESS));
}
@Override // so we can see it
public Dimension getPreferredSize() {
return new Dimension(RESIZE_WIDTH, RESIZE_HEIGHT);
}
public void setFill(boolean fill) {
Color fillColor = fill ? FILL_COLOR : null;
setBackground(fillColor);
repaint();
}
}