Java Swing編程：進度條和滑動條

前幾天講了Swing基本的控件，今天開始講特殊控件。一天講2個吧，首先講用JProgressBar，ProgressMonitor和BoundedRangeModel來實現進度條。然後講用JSlider和BoundedRangeModel來實現滑動條。

進度條，eg

public class TestJProgressBar  
{  
    JFrame frame = new JFrame("測試進度條");  
    //創建一條垂直進度條  
    JProgressBar bar = new JProgressBar(JProgressBar.VERTICAL );  
    JCheckBox indeterminate = new JCheckBox("不確定進度");  
    JCheckBox noBorder = new JCheckBox("不繪制邊框");  
    public void init()  
    {  
        Box box = new Box(BoxLayout.Y_AXIS);  
        box.add(indeterminate);  
        box.add(noBorder);  
        frame.setLayout(new FlowLayout());  
        frame.add(box);  
        //把進度條添加到JFrame窗口中  
        frame.add(bar);  
 
        //設置在進度條中繪制完成百分比  
        bar.setStringPainted(true);  
        noBorder.addActionListener(new ActionListener()  
        {    
            public void actionPerformed(ActionEvent event)  
            {  
                //根據該選擇框決定是否繪制進度條的邊框  
                bar.setBorderPainted(!noBorder.isSelected());  
            }  
        });  
        final SimulatedTarget target = new SimulatedTarget(1000);  
        //以啟動一條線程的方式來執行一個耗時的任務  
        new Thread(target).start();  
        //設置進度條的最大值和最小值,  
        bar.setMinimum(0);   
        //以總任務量作為進度條的最大值  
        bar.setMaximum(target.getAmount());  
        Timer timer = new Timer(300 , new ActionListener()  
        {  
            public void actionPerformed(ActionEvent e)  
            {  
                //以任務的當前完成量設置進度條的value  
                bar.setValue(target.getCurrent());  
            }  
        });  
        timer.start();  
        indeterminate.addActionListener(new ActionListener()  
        {    
            public void actionPerformed(ActionEvent event)  
            {  
                //設置該進度條的進度是否確定  
                bar.setIndeterminate(indeterminate.isSelected());  
                bar.setStringPainted(!indeterminate.isSelected());  
            }  
        });  
        frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);  
        frame.pack();  
        frame.setVisible(true);  
    }  
    public static void main(String[] args)   
    {  
        new TestJProgressBar().init();  
    }  
}  
//模擬一個耗時的任務  
class SimulatedTarget implements Runnable  
{   
    //任務的當前完成量  
    private volatile int current;  
    //總任務量  
    private int amount;  
    public SimulatedTarget(int amount)  
    {    
        current = 0;  
        this.amount = amount;  
    }  
 
    public int getAmount()  
    {    
      return amount;  
    }  
 
    public int getCurrent()  
    {    
        return current;  
    }  
    //run方法代表不斷完成任務的過程  
    public void run()  
    {    
 
        while (current < amount)  
        {   
            try 
            {  
                Thread.sleep(50);  
            }  
            catch(InterruptedException e)  
            {  
 
            }  
            current++;  
        }  
    }  
} 

SimulatedTarget模擬了一個耗時程序，JProgressBar存在BoundedRangeModel用於保存數據對象。

ProgressMonitor是進度對話框，用起來很方便，但就缺乏了自主性，eg

public class TestProgressMonitor  
{  
    Timer timer;  
    public void init()  
    {  
        final SimulatedTarget target = new SimulatedTarget(1000);  
        //以啟動一條線程的方式來執行一個耗時的任務  
        final Thread targetThread = new Thread(target);  
        targetThread.start();  
        //創建進度對話框  
        final ProgressMonitor dialog = new ProgressMonitor(null ,  
            "等待任務完成" , "已完成：" , 0 , target.getAmount());  
        //創建一個計時器  
        timer = new Timer(300 , new ActionListener()  
        {  
            public void actionPerformed(ActionEvent e)  
            {  
                //以任務的當前完成量設置進度對話框的完成比例  
                dialog.setProgress(target.getCurrent());  
                //如果用戶單擊了進度對話框的”取消“按鈕  
                if (dialog.isCanceled())  
                {  
                    //停止計時器  
                    timer.stop();  
                    //中斷任務的執行線程  
                    targetThread.interrupt();  
                    //系統退出  
                    System.exit(0);  
                }  
            }  
        });  
        timer.start();  
    }  
    public static void main(String[] args)   
    {  
        new TestProgressMonitor().init();  
    }  
} 

這個程序利用了上面的耗時程序。進度條就是那麼簡單。

滑動條和進度條差不多，他們共用一個模型BoundedRangeModel。下面是個滑動條的各樣式的演示例子，eg

public class TestJSlider  
{  
    JFrame mainWin = new JFrame("滑動條示范");  
    Box sliderBox = new Box(BoxLayout.Y_AXIS);  
    JTextFIEld showVal = new JTextFIEld();  
    ChangeListener listener;  
    public void init()   
    {  
        //定義一個監聽器，用於監聽所有滑動條  
        listener = new ChangeListener()  
        {    
            public void stateChanged(ChangeEvent event)  
            {    
                //取出滑動條的值，並在文本中顯示出來  
                JSlider source = (JSlider) event.getSource();  
                showVal.setText("當前滑動條的值為：" + source.getValue());  
            }  
        };  
        //-----------添加一個普通滑動條-----------  
        JSlider slider = new JSlider();  
        addSlider(slider, "普通滑動條");  
 
        //-----------添加保留區為30的滑動條-----------  
        slider = new JSlider();  
        slider.setExtent(30);  
        addSlider(slider, "保留區為30");  
 
        //-----------添加帶主、次刻度的滑動條,並設置其最大值，最小值-----------  
        slider = new JSlider(30 , 200);  
        //設置繪制刻度  
        slider.setPaintTicks(true);  
        //設置主、次刻度的間距  
        slider.setMajorTickSpacing(20);  
        slider.setMinorTickSpacing(5);  
        addSlider(slider, "有刻度");  
 
        //-----------添加滑塊必須停在刻度處滑動條-----------  
        slider = new JSlider();  
        //設置滑塊必須停在刻度處  
        slider.setSnapToTicks(true);  
        //設置繪制刻度  
        slider.setPaintTicks(true);  
        //設置主、次刻度的間距  
        slider.setMajorTickSpacing(20);  
        slider.setMinorTickSpacing(5);  
        addSlider(slider, "滑塊停在刻度處");  
 
        //-----------添加沒有滑軌的滑動條-----------  
        slider = new JSlider();  
        //設置繪制刻度  
        slider.setPaintTicks(true);  
        //設置主、次刻度的間距  
        slider.setMajorTickSpacing(20);  
        slider.setMinorTickSpacing(5);  
        //設置不繪制滑軌  
        slider.setPaintTrack(false);  
        addSlider(slider, "無滑軌");  
 
        //-----------添加方向反轉的滑動條-----------  
        slider = new JSlider();  
        //設置繪制刻度  
        slider.setPaintTicks(true);  
        //設置主、次刻度的間距  
        slider.setMajorTickSpacing(20);  
        slider.setMinorTickSpacing(5);  
        //設置方向反轉  
        slider.setInverted(true);  
        addSlider(slider, "方向反轉");  
 
        //-----------添加繪制默認刻度標簽的滑動條-----------  
        slider = new JSlider();  
        //設置繪制刻度  
        slider.setPaintTicks(true);  
        //設置主、次刻度的間距  
        slider.setMajorTickSpacing(20);  
        slider.setMinorTickSpacing(5);  
        //設置繪制刻度標簽，默認繪制數值刻度標簽  
        slider.setPaintLabels(true);  
        addSlider(slider, "數值刻度標簽");  
 
        //-----------添加繪制Label類型的刻度標簽的滑動條-----------   
        slider = new JSlider();  
        //設置繪制刻度  
        slider.setPaintTicks(true);  
        //設置主、次刻度的間距  
        slider.setMajorTickSpacing(20);  
        slider.setMinorTickSpacing(5);  
        //設置繪制刻度標簽  
        slider.setPaintLabels(true);  
        Dictionary<Integer, Component> labelTable = new Hashtable<Integer, Component>();  
        labelTable.put(0, new JLabel("A"));  
        labelTable.put(20, new JLabel("B"));  
        labelTable.put(40, new JLabel("C"));  
        labelTable.put(60, new JLabel("D"));  
        labelTable.put(80, new JLabel("E"));  
        labelTable.put(100, new JLabel("F"));  
        //指定刻度標簽，標簽是JLabel  
        slider.setLabelTable(labelTable);  
        addSlider(slider, "JLable標簽");  
 
        //-----------添加繪制Label類型的刻度標簽的滑動條-----------   
        slider = new JSlider();  
        //設置繪制刻度  
        slider.setPaintTicks(true);  
        //設置主、次刻度的間距  
        slider.setMajorTickSpacing(20);  
        slider.setMinorTickSpacing(5);  
        //設置繪制刻度標簽  
        slider.setPaintLabels(true);  
        labelTable = new Hashtable<Integer, Component>();  
        labelTable.put(0, new JLabel(new ImageIcon("ico/0.GIF")));  
        labelTable.put(20, new JLabel(new ImageIcon("ico/2.GIF")));  
        labelTable.put(40, new JLabel(new ImageIcon("ico/4.GIF")));  
        labelTable.put(60, new JLabel(new ImageIcon("ico/6.GIF")));  
        labelTable.put(80, new JLabel(new ImageIcon("ico/8.GIF")));  
        //指定刻度標簽，標簽是ImageIcon  
        slider.setLabelTable(labelTable);  
        addSlider(slider, "Icon標簽");  
 
        mainWin.add(sliderBox, BorderLayout.CENTER);  
        mainWin.add(showVal, BorderLayout.SOUTH);  
        mainWin.pack();  
        mainWin.setVisible(true);  
 
    }  
    //定義一個方法，用於將滑動條添加到容器中  
    public void addSlider(JSlider slider, String description)  
    {          
        slider.addChangeListener(listener);  
        Box box = new Box(BoxLayout.X_AXIS);  
        box.add(new JLabel(description + "："));  
        box.add(slider);  
        sliderBox.add(box);  
    }  
 
    public static void main(String[] args)  
    {  
        new TestJSlider().init();  
    }  
}