Question

我在JPanel上设置了背景图像但是当我尝试添加按钮并选择自定义背景面板时，按钮被隐藏，直到我将鼠标移到按钮上。我在下面列出了代码段。

以下是我自定义的JPanel

package au.com.tankwarz.view.custompanels;

import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;

import javax.swing.JPanel;

public class BackgroundPanel extends JPanel
{

    /**
     * 
     */
    private static final long serialVersionUID = 1659728640545162103L;

    public BackgroundPanel()
    {
    }

    @Override
    public void paintComponent(final Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D)g;
        g2d.drawImage(loadBackgroundImage(), 0, 0, this);    

        g2d.dispose();  
    }   

    private static BufferedImage loadBackgroundImage()
    {
         BufferedImage bi = new BufferedImage(800, 600, BufferedImage.TYPE_INT_ARGB);
         Graphics2D g2d = bi.createGraphics();
         g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

         // Paint a gradient from top to bottom
        GradientPaint gp = new GradientPaint( 0, 0, Color.BLACK, 0, 600, new Color(0, 0, 255).darker( ).darker() );

        g2d.setPaint( gp );
        g2d.fillRect( 0, 0, 800, 600 );

        g2d.dispose();

        return bi;
    }
}

这里是我尝试使用它来显示面板上的按钮的地方。

package au.com.tankwarz.view;
import java.awt.event.ActionListener;

import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;

import org.jdesktop.application.Application;

import au.com.tankwarz.view.custompanels.BackgroundPanel;

import com.cloudgarden.layout.AnchorConstraint;
import com.cloudgarden.layout.AnchorLayout;

public class NewGamePanel extends BackgroundPanel {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    private JLabel numberOfPlayersLable;
    private JComboBox numberOfPlayersCB;
    private JButton cancelButton;
    private JButton createPlayersButton;
    private JComboBox numberOfTanksCB;
    private JLabel numberOfTanksLable;
    private JComboBox numberOfRoundsCB;
    private JLabel numberOfRounds;

    public static final String[] numberOfPlayersCBValues = new String[] { "Two", "Three", "Four" };

    public static final String[] numberOfRoundsCBValues = new String[] { "One", "Two", "Three", "Four" };

    public static final String[] numberOfTanksCBValues = new String[] { "One", "Two", "Three", "Four" };

    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                //new NewGamePanel();


                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new NewGamePanel());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });


    }

    public NewGamePanel() {
        super();
        initGUI();
    }

    private void initGUI() {
        try {
            AnchorLayout thisLayout = new AnchorLayout();
            this.setLayout(thisLayout);
            this.setPreferredSize(new java.awt.Dimension(800, 600));
            this.setSize(800, 600);
            this.setOpaque(true);
            this.setName("this");
            {
                numberOfPlayersLable = new JLabel();
                this.add(numberOfPlayersLable, new AnchorConstraint(144, 320, 201, 77, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                numberOfPlayersLable.setName("numberOfPlayersLable");
                numberOfPlayersLable.setPreferredSize(new java.awt.Dimension(60, 40));
            }
            {
                ComboBoxModel numberOfPlayersCBModel = 
                    new DefaultComboBoxModel(numberOfPlayersCBValues);
                numberOfPlayersCB = new JComboBox();
                this.add(numberOfPlayersCB, new AnchorConstraint(125, 697, 219, 386, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                numberOfPlayersCB.setModel(numberOfPlayersCBModel);
                numberOfPlayersCB.setPreferredSize(new java.awt.Dimension(60, 40));
            }
            {
                numberOfRounds = new JLabel();
                this.add(numberOfRounds, new AnchorConstraint(298, 371, 355, 77, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                numberOfRounds.setName("numberOfRounds");
                numberOfRounds.setPreferredSize(new java.awt.Dimension(60, 40));
            }
            {
                ComboBoxModel numberOfRoundsCBModel = 
                    new DefaultComboBoxModel(numberOfRoundsCBValues);
                numberOfRoundsCB = new JComboBox();
                this.add(numberOfRoundsCB, new AnchorConstraint(283, 697, 366, 386, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                numberOfRoundsCB.setModel(numberOfRoundsCBModel);
                numberOfRoundsCB.setName("numberOfRoundsCB");
                numberOfRoundsCB.setPreferredSize(new java.awt.Dimension(60, 40));
            }
            {
                numberOfTanksLable = new JLabel();
                this.add(numberOfTanksLable, new AnchorConstraint(453, 320, 509, 77, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                numberOfTanksLable.setName("numberOfTanksLable");
                numberOfTanksLable.setPreferredSize(new java.awt.Dimension(60, 40));
            }
            {
                ComboBoxModel numberOfTanksCBModel = 
                    new DefaultComboBoxModel(numberOfTanksCBValues);
                numberOfTanksCB = new JComboBox();
                this.add(numberOfTanksCB, new AnchorConstraint(437, 697, 520, 386, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                numberOfTanksCB.setModel(numberOfTanksCBModel);
                numberOfTanksCB.setPreferredSize(new java.awt.Dimension(60, 40));
            }
            {
                createPlayersButton = new JButton();
                this.add(createPlayersButton, new AnchorConstraint(795, 758, 878, 511, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                createPlayersButton.setName("createPlayersButton");
                createPlayersButton.setPreferredSize(new java.awt.Dimension(99, 25));
            }
            {
                cancelButton = new JButton();
                this.add(cancelButton, new AnchorConstraint(795, 248, 878, 128, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL, AnchorConstraint.ANCHOR_REL));
                cancelButton.setName("cancelButton");
                cancelButton.setPreferredSize(new java.awt.Dimension(48, 25));
            }
            Application.getInstance().getContext().getResourceMap(getClass()).injectComponents(this);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void setCreatePlayersButtonActionListener(ActionListener actionListener)
    {
        createPlayersButton.addActionListener(actionListener);
    }

    public void setCancelButtonActionListener(ActionListener actionListener)
    {
        cancelButton.addActionListener(actionListener);
    }

    public JComboBox getNumberOfPlayersCB()
    {
        return numberOfPlayersCB;
    }

    public void setNumberOfPlayersCB(JComboBox numberOfPlayersCB)
    {
        this.numberOfPlayersCB = numberOfPlayersCB;
    }

    public JComboBox getNumberOfTanksCB()
    {
        return numberOfTanksCB;
    }

    public void setNumberOfTanksCB(JComboBox numberOfTanksCB)
    {
        this.numberOfTanksCB = numberOfTanksCB;
    }

    public JComboBox getNumberOfRoundsCB()
    {
        return numberOfRoundsCB;
    }

    public void setNumberOfRoundsCB(JComboBox numberOfRoundsCB)
    {
        this.numberOfRoundsCB = numberOfRoundsCB;
    }

}

任何帮助都会受到赞赏，因为我一直在努力解决这个问题。

Answer 1

不要在任何paintXxx方法中更改组件的状态，这可能会导致重启事件，重复此过程，直到CPU运行不热。
永远不要在任何paintXxx内更改组件的不透明度状态，这将导致一系列重复的重绘，因为Swing突然开始尝试找出当前可见的组件...
不要处置您未创建的Graphics上下文，这样做可能会阻止您在某些系统上呈现之后所绘制的内容。
尽量不要在每个绘制周期中创建背景图像，这不仅从内存的角度来看很昂贵，而且从时间的角度来看也很昂贵

我不确定你为什么要翻转不透明状态，你真的不希望它是透明的。只需致电super.paintComponent以准备图形状态，然后将图像绘制在顶部。

您还应避免使用setPreferredSize，有关详细信息，请参阅Should I avoid the use of set(Preferred|Maximum|Minimum)Size methods in Java Swing? ...

只是说明一点，这是你编码产生的（在我纠正了油漆问题之后）

enter image description here

这是我的测试代码产生的

enter image description here

已更新测试代码

import com.apple.eawt.Application;
import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.RenderingHints;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.swing.ComboBoxModel;
import javax.swing.DefaultComboBoxModel;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class BackgroundPanel extends JPanel {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                //new NewGamePanel();

                JFrame frame = new JFrame("Test");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new NewGamePanel());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }

        });

    }

    public BackgroundPanel() {
    }

    private static BufferedImage bi;

    @Override
    public void paintComponent(final Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g.create();
        g2d.drawImage(loadBackgroundImage(), 0, 0, this);
        g2d.dispose();
    }

    private static BufferedImage loadBackgroundImage() {
        if (bi == null) {
            bi = new BufferedImage(800, 600, BufferedImage.TYPE_INT_ARGB);
            Graphics2D g2d = bi.createGraphics();
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

            // Paint a gradient from top to bottom
            GradientPaint gp = new GradientPaint(0, 0, Color.BLACK, 0, 600, new Color(0, 0, 255).darker().darker());

            g2d.setPaint(gp);
            g2d.fillRect(0, 0, 800, 600);

            g2d.dispose();
        }

        return bi;
    }

    public static class NewGamePanel extends BackgroundPanel {

        /**
         *
         */
        private static final long serialVersionUID = 1L;
        private JLabel numberOfPlayersLable;
        private JComboBox numberOfPlayersCB;
        private JButton cancelButton;
        private JButton createPlayersButton;
        private JComboBox numberOfTanksCB;
        private JLabel numberOfTanksLable;
        private JComboBox numberOfRoundsCB;
        private JLabel numberOfRounds;

        public static final String[] numberOfPlayersCBValues = new String[]{"Two", "Three", "Four"};

        public static final String[] numberOfRoundsCBValues = new String[]{"One", "Two", "Three", "Four"};

        public static final String[] numberOfTanksCBValues = new String[]{"One", "Two", "Three", "Four"};

        public NewGamePanel() {
            super();
            initGUI();
        }

        private void initGUI() {
            try {
                GridBagLayout thisLayout = new GridBagLayout();
                this.setLayout(thisLayout);
                this.setPreferredSize(new java.awt.Dimension(800, 600));
                this.setSize(800, 600);
                this.setOpaque(true);
                this.setName("this");

                GridBagConstraints gbc = new GridBagConstraints();
                gbc.gridwidth = gbc.REMAINDER;
                {
                    numberOfPlayersLable = new JLabel();
                    this.add(numberOfPlayersLable, gbc);
                    numberOfPlayersLable.setName("numberOfPlayersLable");
                }
                {
                    ComboBoxModel numberOfPlayersCBModel
                                    = new DefaultComboBoxModel(numberOfPlayersCBValues);
                    numberOfPlayersCB = new JComboBox();
                    this.add(numberOfPlayersCB, gbc);
                    numberOfPlayersCB.setModel(numberOfPlayersCBModel);
                }
                {
                    numberOfRounds = new JLabel();
                    this.add(numberOfRounds, gbc);
                    numberOfRounds.setName("numberOfRounds");
                }
                {
                    ComboBoxModel numberOfRoundsCBModel
                                    = new DefaultComboBoxModel(numberOfRoundsCBValues);
                    numberOfRoundsCB = new JComboBox();
                    this.add(numberOfRoundsCB, gbc);
                    numberOfRoundsCB.setModel(numberOfRoundsCBModel);
                    numberOfRoundsCB.setName("numberOfRoundsCB");
                }
                {
                    numberOfTanksLable = new JLabel();
                    this.add(numberOfTanksLable, gbc);
                    numberOfTanksLable.setName("numberOfTanksLable");
                }
                {
                    ComboBoxModel numberOfTanksCBModel
                                    = new DefaultComboBoxModel(numberOfTanksCBValues);
                    numberOfTanksCB = new JComboBox();
                    this.add(numberOfTanksCB, gbc);
                    numberOfTanksCB.setModel(numberOfTanksCBModel);
                }
                {
                    createPlayersButton = new JButton();
                    this.add(createPlayersButton, gbc);
                    createPlayersButton.setName("createPlayersButton");
                }
                {
                    cancelButton = new JButton();
                    this.add(cancelButton, gbc);
                    cancelButton.setName("cancelButton");
                }
//                Application.getInstance().getContext().getResourceMap(getClass()).injectComponents(this);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public void setCreatePlayersButtonActionListener(ActionListener actionListener) {
            createPlayersButton.addActionListener(actionListener);
        }

        public void setCancelButtonActionListener(ActionListener actionListener) {
            cancelButton.addActionListener(actionListener);
        }

        public JComboBox getNumberOfPlayersCB() {
            return numberOfPlayersCB;
        }

        public void setNumberOfPlayersCB(JComboBox numberOfPlayersCB) {
            this.numberOfPlayersCB = numberOfPlayersCB;
        }

        public JComboBox getNumberOfTanksCB() {
            return numberOfTanksCB;
        }

        public void setNumberOfTanksCB(JComboBox numberOfTanksCB) {
            this.numberOfTanksCB = numberOfTanksCB;
        }

        public JComboBox getNumberOfRoundsCB() {
            return numberOfRoundsCB;
        }

        public void setNumberOfRoundsCB(JComboBox numberOfRoundsCB) {
            this.numberOfRoundsCB = numberOfRoundsCB;
        }

    }

}

按钮被背景图像隐藏

1 个答案: