当用户将鼠标悬停在JTextArea上时,我想为其添加边框。这一切都很好,我这样做是:
public void mouseMoved(MouseEvent e) {
Border border = BorderFactory.createLineBorder(Color.black);
JTextArea component = (JTextArea) e.getComponent();
component.setBorder(border);
}
我的问题是:当用户没有将鼠标悬停在JTextArea上时,我想删除边框。反正我能做到吗?我必须在JPanel内执行此操作,还是可以在侦听器类中执行此操作?您可以在此处看到,当我将鼠标移到JPanel上(而不是JTextArea上)时,边框保持不变:
import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.border.Border;
import javax.swing.event.MouseInputAdapter;
public class Editor {
public static void main(String[] args) {
JFrame frame = new Window();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setBounds(30, 30, 1000, 700);
frame.getContentPane().setBackground(Color.white);
frame.setVisible(true);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
class Window extends JFrame {
MyPanel myPanel = new MyPanel();
private static final long serialVersionUID = 1L;
public Window() {
addMenus();
}
public void addMenus() {
getContentPane().add(myPanel);
setSize(300, 200);
setLocationRelativeTo(null);
setDefaultCloseOperation(EXIT_ON_CLOSE);
}
}
class MyPanel extends JPanel {
private static final long serialVersionUID = 1L;
DragListener drag;
public MyPanel() {
drag = new DragListener();
addBox();
}
public void addBox() {
setLayout(new DragLayout());
drag = new DragListener();
JTextArea textArea2 = new JTextArea("Text Box Added");
textArea2.setLineWrap(true);
textArea2.setWrapStyleWord(true);
add(textArea2);
textArea2.addMouseListener(drag);
textArea2.addMouseMotionListener(drag);
repaint();
revalidate();
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
}
public class DragListener extends MouseInputAdapter {
Point location;
MouseEvent pressed;
public void mousePressed(MouseEvent me) {
pressed = me;
}
public void mouseDragged(MouseEvent me) {
Component component = me.getComponent();
location = component.getLocation(location);
int x = location.x - pressed.getX() + me.getX();
int y = location.y - pressed.getY() + me.getY();
component.setLocation(x, y);
}
public void mouseMoved(MouseEvent e) {
Border border = BorderFactory.createLineBorder(Color.black);
JTextArea component = (JTextArea) e.getComponent();
component.setBorder(border);
}
}
}
最佳答案
使用MouseEntered
的MouseExited
和MouseListener
事件,这将在鼠标进入或存在于组件中时通知您
有关更多详细信息,请参见How to Write a Mouse Listener