Question

我在Oracle网站上发现了这个test project因为我想在我的项目中添加循环进度条。

我正在使用Netbeans开发应用程序，当我启动应用程序时，应该使用圆圈的JPanel ....令人失望。

我删除了所有无法解决此问题的代码，并且我已经获得了此代码：

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import javax.swing.*;
import javax.swing.plaf.LayerUI;


public class Loading_Test extends javax.swing.JFrame
{
    static final WaitLayerUI layerUI = new WaitLayerUI();
    public Loading_Test()
    {

        JPanel panel = new JPanel();
        JLayer<JPanel> jlayer = new JLayer<>(panel, layerUI);
        add(jlayer);

        initComponents();
    }

    @SuppressWarnings("unchecked")
    private void initComponents() {

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 300, Short.MAX_VALUE)
        );

        pack();
    }

    public static void main(String args[])
    {
        java.awt.EventQueue.invokeLater(new Runnable()
        {

            @Override
            public void run()
            {                
                JFrame frame = new Loading_Test();
                frame.setVisible(true);
                layerUI.start();
            }
        });
    }
}
class WaitLayerUI extends LayerUI<JPanel> implements ActionListener
{

    private boolean mIsRunning;
    private boolean mIsFadingOut;
    private Timer mTimer;
    private int mAngle;
    private int mFadeCount;
    private int mFadeLimit = 15;

    @Override
    public void paint(Graphics g, JComponent c)
    {
        int w = c.getWidth();
        int h = c.getHeight();

        // Paint the view.
        super.paint(g, c);

        if (!mIsRunning)
        {
            return;
        }

        Graphics2D g2 = (Graphics2D) g.create();

        float fade = (float) mFadeCount / (float) mFadeLimit;
        // Gray it out.
        Composite urComposite = g2.getComposite();
        g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .5f * fade));
        g2.fillRect(0, 0, w, h);
        g2.setComposite(urComposite);

        // Paint the wait indicator.
        int s = Math.min(w, h) / 5;
        int cx = w / 2;
        int cy = h / 2;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setStroke(new BasicStroke(s / 4, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
        g2.setPaint(Color.white);
        g2.rotate(Math.PI * mAngle / 180, cx, cy);
        for (int i = 0; i < 12; i++)
        {
            float scale = (11.0f - (float) i) / 11.0f;
            g2.drawLine(cx + s, cy, cx + s * 2, cy);
            g2.rotate(-Math.PI / 6, cx, cy);
            g2.setComposite(AlphaComposite.getInstance(
                    AlphaComposite.SRC_OVER, scale * fade));
        }

        g2.dispose();
    }

    @Override
    public void actionPerformed(ActionEvent e)
    {
        if (mIsRunning)
        {
            firePropertyChange("tick", 0, 1);
            mAngle += 3;
            if (mAngle >= 360)
            {
                mAngle = 0;
            }
            if (mIsFadingOut)
            {
                if (--mFadeCount == 0)
                {
                    mIsRunning = false;
                    mTimer.stop();
                }
            }
            else if (mFadeCount < mFadeLimit)
            {
                mFadeCount++;
            }
        }
    }

    public void start()
    {
        if (mIsRunning)
        {
            return;
        }

        // Run a thread for animation.
        mIsRunning = true;
        mIsFadingOut = false;
        mFadeCount = 0;
        int fps = 24;
        int tick = 1000 / fps;
        mTimer = new Timer(tick, this);
        mTimer.start();
    }

    public void stop()
    {
        mIsFadingOut = true;
    }

    @Override
    public void applyPropertyChange(PropertyChangeEvent pce, JLayer l)
    {
        if ("tick".equals(pce.getPropertyName()))
        {
            l.repaint();
        }
    }
}

如果你“按原样”运行此代码，你应该有同样的问题，JPanel没有显示。

但我发现如果删除与布局相关的行（27~36），进度条就会开始工作。

您还必须手动设置窗口大小添加

setSize(300, 300);

之后

pack();

因为布局线是由Netbeans自动生成的，所以我试图了解如何解决这个问题，因为这些特定的代码行被Netbeans编辑器阻止编辑。

Answer 1

我有一天失去了它仍然没有工作......我将在JLabel上使用GIF动画....故事结束！

@Robin有重要的信息，好像你受限于使用GuiBulder ......，那么我不想发表评论，结果是

enter image description here

来自一点点修改过的代码

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.beans.PropertyChangeEvent;
import javax.swing.*;
import javax.swing.plaf.LayerUI;

public class Loading_Test {

    static final WaitLayerUI layerUI = new WaitLayerUI();
    JFrame frame = new JFrame("JLayer With Animated Gif");

    public Loading_Test() {
        JPanel panel = new JPanel() {

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(400, 300);
            }
        };
        JLayer<JPanel> jlayer = new JLayer<>(panel, layerUI);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(jlayer);
        frame.pack();
        frame.setVisible(true);
        layerUI.start();
    }

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                Loading_Test loading_Test = new Loading_Test();

            }
        });
    }
}

class WaitLayerUI extends LayerUI<JPanel> implements ActionListener {

    private boolean mIsRunning;
    private boolean mIsFadingOut;
    private Timer mTimer;
    private int mAngle;
    private int mFadeCount;
    private int mFadeLimit = 15;

    @Override
    public void paint(Graphics g, JComponent c) {
        int w = c.getWidth();
        int h = c.getHeight();
        super.paint(g, c); // Paint the view.
        if (!mIsRunning) {
            return;
        }
        Graphics2D g2 = (Graphics2D) g.create();
        float fade = (float) mFadeCount / (float) mFadeLimit;
        Composite urComposite = g2.getComposite(); // Gray it out.
        g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, .5f * fade));
        g2.fillRect(0, 0, w, h);
        g2.setComposite(urComposite);
        int s = Math.min(w, h) / 5;// Paint the wait indicator.
        int cx = w / 2;
        int cy = h / 2;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setStroke(new BasicStroke(s / 4, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND));
        g2.setPaint(Color.white);
        g2.rotate(Math.PI * mAngle / 180, cx, cy);
        for (int i = 0; i < 12; i++) {
            float scale = (11.0f - (float) i) / 11.0f;
            g2.drawLine(cx + s, cy, cx + s * 2, cy);
            g2.rotate(-Math.PI / 6, cx, cy);
            g2.setComposite(AlphaComposite.getInstance(
                    AlphaComposite.SRC_OVER, scale * fade));
        }
        g2.dispose();
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        if (mIsRunning) {
            firePropertyChange("tick", 0, 1);
            mAngle += 3;
            if (mAngle >= 360) {
                mAngle = 0;
            }
            if (mIsFadingOut) {
                if (--mFadeCount == 0) {
                    mIsRunning = false;
                    mTimer.stop();
                }
            } else if (mFadeCount < mFadeLimit) {
                mFadeCount++;
            }
        }
    }

    public void start() {
        if (mIsRunning) {
            return;
        }
        mIsRunning = true;// Run a thread for animation.
        mIsFadingOut = false;
        mFadeCount = 0;
        int fps = 24;
        int tick = 1000 / fps;
        mTimer = new Timer(tick, this);
        mTimer.start();
    }

    public void stop() {
        mIsFadingOut = true;
    }

    @Override
    public void applyPropertyChange(PropertyChangeEvent pce, JLayer l) {
        if ("tick".equals(pce.getPropertyName())) {
            l.repaint();
        }
    }
}

必须添加两个JButtons，一个用于开始，第二个用于停止（显示和隐藏动画Gig）
请勿伪造JPanel已实施FlowLayout，非常接受PreferredSize来自其子女，

Answer 2

通过SwingLabs

找到了一个更好的简单（和工作）解决方案，其中包含Swing Components Extension

<强> JXBusyLabel

为编辑器提供了一个完全集成的NetBeans插件，因此使用起来非常简单

Answer 3

从您的问题和评论来看，您在Netbeans中实施JLayer时遇到问题，我建议您选择CardLayout，这样您就可以在正常{{1}之间切换和微调器的那个。

这是一个简单的教程：CardLayout With Netbeans

Java Swing循环进度条不起作用

3 个答案: