Question

enter image description here

我想创建一个这样的框架。其中是一个0.9不透明度的主框架，并保持两个JPanel s。其中一个面板是黑色的，另一个面板没有任何背景颜色e：g setOpaque(false);。

这是我尝试过的但没有用的：

的JFrame

public class STBG {
    JFrame frame = new JFrame("Panel");
    BorderLayout bl = new BorderLayout();

    public STBG(){
        frame.setLayout(bl);
        frame.setSize(800, 600);
        frame.add(new LeftBar(), BorderLayout.WEST);
        frame.add(new MainPanel(), BorderLayout.CENTER);

       //frame.setUndecorated(true);
       frame.setBackground(new Color(0, 255, 0, 1));

        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    public static void main(String[] args) throws IOException {
        // TODO code application logic here
        new STBG();
    }
}

LEFT PANEL

public class LeftBar extends JPanel{
    JPanel menuPanel;
    JLabel schedule, history, settings, aboutApp;
    public LeftBar(){
        setBackground(Color.BLACK);
        setPreferredSize(new Dimension(100, 20));
        setLayout(new BorderLayout());
        menuPanel = new JPanel(new GridLayout(5,0));
        menuPanel.setBackground(Color.black);


        settings = new JLabel("Settings");
        schedule = new JLabel("Schedule");
        history = new JLabel("History");
        menuPanel.add(settings);
        menuPanel.add(schedule);
        menuPanel.add(history);

        aboutApp = new JLabel("About App");
        add(menuPanel, BorderLayout.CENTER);
        add(aboutApp, BorderLayout.SOUTH);
    }
}

MAIN PANEL

public class MainPanel extends JPanel{
    public MainPanel(){
        setLayout(new GridLayout(0,1));
        add(new JLabel("TEXT"));

        setOpaque(false);
        setBackground(new Color(0, 0, 0, 1));
    }
}

知道如何制作类似图像的东西吗？

Answer 1

尽管tutorials似乎在说什么，但似乎没有任何方法可以使框架内容区域透明而不会使框架被涂层。

Swing组件（除JFrame之外）不能很好地渲染透明背景颜色，这个过程不会导致绘画工件和其他相关问题的结束。

然而，你可以＆＃34;假＆＃34;它。首先让JPanel透明（setOpaque(false)），然后覆盖它的paintComponent方法并绘制您想要的填充颜色，例如......

Fade

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.LinearGradientPaint;
import java.awt.Point;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class JavaApplication1048 {

    public static void main(String[] args) {
        new JavaApplication1048();
    }

    public JavaApplication1048() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                    ex.printStackTrace();
                }

                System.out.println("Blah");

                JFrame frame = new JFrame("Testing");
                frame.setLayout(new GridLayout(1, 2));
                frame.setUndecorated(true);
                frame.setBackground(new Color(0, 255, 0, 0));
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new LeftPane());
                frame.add(new RightPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class LeftPane extends JPanel {

        public LeftPane() {
            JLabel label = new JLabel("Left");
            label.setForeground(Color.WHITE);
            setBackground(Color.BLACK);
            add(label);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(100, 100);
        }

    }

    public class RightPane extends JPanel {

        public RightPane() {
            JLabel label = new JLabel("Right");
            label.setForeground(Color.WHITE);
            setBackground(Color.BLACK);
            add(label);
            setOpaque(false);
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(100, 100);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2d = (Graphics2D) g.create();
            LinearGradientPaint lgp = new LinearGradientPaint(
                            new Point(0, 0),
                            new Point(getWidth(), 0),
                            new float[]{0f, 1f},
                            new Color[]{getBackground(), applyAlpha(getBackground(), 0.5f)}
            );
            g2d.setPaint(lgp);
            g2d.fillRect(0, 0, getWidth(), getHeight());
            g2d.dispose();
        }

        protected Color applyAlpha(Color color, float alpha) {

            return new Color(color.getRed(), color.getGreen(), color.getBlue(), Math.round(255 * alpha));

        }

    }

}

Answer 2

我刚刚修改了How to Create Translucent Windows上Swing教程中的一个示例。它似乎适用于金属LAF，所以至少你会有按钮。

import java.awt.*;
import javax.swing.*;
import static java.awt.GraphicsDevice.WindowTranslucency.*;

public class FrameTranslucent extends JFrame {
    public FrameTranslucent() {
        super("Frame Translucent");

        setBackground(new Color(0,0,0,0));
        setSize(new Dimension(300,200));
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        JPanel panel = new JPanel(new BorderLayout()) {
            @Override
            protected void paintComponent(Graphics g) {
                if (g instanceof Graphics2D) {
                    final int R = 240;
                    final int G = 240;
                    final int B = 240;

                    Paint p =
                        new GradientPaint(0.0f, 0.0f, new Color(R, G, B, 0),
                            0.0f, getHeight(), new Color(R, G, B, 255), true);
                    Graphics2D g2d = (Graphics2D)g;
                    g2d.setPaint(p);
                    g2d.fillRect(0, 0, getWidth(), getHeight());
                }
            }
        };
        setContentPane(panel);

        JPanel left = new JPanel( new BorderLayout() );
        left.setBackground( Color.BLACK );
        left.add(new JLabel("Left Label Text"), BorderLayout.NORTH);
        add(left, BorderLayout.WEST);

        JPanel center = new JPanel( new BorderLayout() );
        center.setBackground( new Color(0, 0, 0, 128) );
        JLabel label = new JLabel("Center Label Text");
        label.setForeground(Color.RED);
        center.add(label, BorderLayout.NORTH);
        add(center, BorderLayout.CENTER);
    }

    public static void main(String[] args) {
        // Determine what the GraphicsDevice can support.
        GraphicsEnvironment ge =
            GraphicsEnvironment.getLocalGraphicsEnvironment();
        GraphicsDevice gd = ge.getDefaultScreenDevice();
        boolean isPerPixelTranslucencySupported =
            gd.isWindowTranslucencySupported(PERPIXEL_TRANSLUCENT);

        //If translucent windows aren't supported, exit.
        if (!isPerPixelTranslucencySupported) {
            System.out.println(
                "Per-pixel translucency is not supported");
                System.exit(0);
        }

        JFrame.setDefaultLookAndFeelDecorated(true);

        // Create the GUI on the event-dispatching thread
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                FrameTranslucent gtw = new FrameTranslucent();

                // Display the window.
                gtw.setVisible(true);
            }
        });
    }
}

我没有发现任何问题，但我确定你想要的确切。

我在使用透明背景时也注意到了问题，这就是我创建Alpha Container以确保正确绘制背景的原因。如果这个例子不起作用，那么AlphaContainer可能会有所帮助。

如何减少JFrame背景颜色的不透明度

2 个答案: