我想创建一个半透明的JPanel。我已经通过简单地使用颜色构造函数的RGBA值来完成它,但问题是当我使用事件处理不正确地开火时。我的要求是一个半透明的Jpanel,当鼠标进入这个面板的边界变得可见时,如果鼠标退出边界不可见。我已经通过下面的代码做到了这一点,但问题是它对于透明背景(RGBA)不能正常工作,但它对RGB颜色工作正常。透明JPanel
import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
public class MDCW extends JFrame {
private JPanel contentPane;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MDCW frame = new MDCW();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public MDCW() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 1013, 551);
contentPane = new JPanel();
contentPane.setBackground(new Color(0, 139, 139));
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
final JPanel panel = new JPanel();
panel.setBackground(new Color(0, 0, 0,50));
panel.addMouseListener(new MouseAdapter() {
@Override
public void mouseEntered(MouseEvent e) {
panel.setBorder(new LineBorder(new Color(255, 255, 255), 5));
}
@Override
public void mouseExited(MouseEvent e) {
panel.setBorder(null);
}
});
panel.setBounds(360, 155, 215, 215);
contentPane.add(panel);
final JPanel panel_1 = new JPanel();
panel_1.setBackground(new Color(0, 0, 0));
panel_1.addMouseListener(new MouseAdapter() {
@Override
public void mouseEntered(MouseEvent e) {
panel_1.setBorder(new LineBorder(new Color(255, 255, 255), 5));
}
@Override
public void mouseExited(MouseEvent e) {
panel_1.setBorder(null);
}
});
panel_1.setBounds(84, 155, 215, 215);
contentPane.add(panel_1);
}
}
想必搜索发现此之前2对我们的!为什么哦为什么不能jpanel只有像JFrame一样的setOpacity方法? – 2016-10-27 16:19:52