疯狂JAVA讲义---第十二章：Swing编程（五）进度条和滑动条

前几天讲了Swing基本的控件，今天开始讲特殊控件。一天讲2个吧，首先讲用JProgressBar，ProgressMonitor和BoundedRangeModel来实现进度条。然后讲用JSlider和BoundedRangeModel来实现滑动条。

进度条，eg

public class TestJProgressBar { JFrame frame = new JFrame("测试进度条"); //创建一条垂直进度条 JProgressBar bar = new JProgressBar(JProgressBar.VERTICAL ); JCheckBox indeterminate = new JCheckBox("不确定进度"); JCheckBox noBorder = new JCheckBox("不绘制边框"); public void init() { Box box = new Box(BoxLayout.Y_AXIS); box.add(indeterminate); box.add(noBorder); frame.setLayout(new FlowLayout()); frame.add(box); //把进度条添加到JFrame窗口中 frame.add(bar); //设置在进度条中绘制完成百分比 bar.setStringPainted(true); noBorder.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { //根据该选择框决定是否绘制进度条的边框 bar.setBorderPainted(!noBorder.isSelected()); } }); final SimulatedTarget target = new SimulatedTarget(1000); //以启动一条线程的方式来执行一个耗时的任务 new Thread(target).start(); //设置进度条的最大值和最小值, bar.setMinimum(0); //以总任务量作为进度条的最大值 bar.setMaximum(target.getAmount()); Timer timer = new Timer(300 , new ActionListener() { public void actionPerformed(ActionEvent e) { //以任务的当前完成量设置进度条的value bar.setValue(target.getCurrent()); } }); timer.start(); indeterminate.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { //设置该进度条的进度是否确定 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(); } } //模拟一个耗时的任务 class SimulatedTarget implements Runnable { //任务的当前完成量 private volatile int current; //总任务量 private int amount; public SimulatedTarget(int amount) { current = 0; this.amount = amount; } public int getAmount() { return amount; } public int getCurrent() { return current; } //run方法代表不断完成任务的过程 public void run() { while (current < amount) { try { Thread.sleep(50); } catch(InterruptedException e) { } current++; } } }

SimulatedTarget模拟了一个耗时程序，JProgressBar存在BoundedRangeModel用于保存数据对象。ProgressMonitor是进度对话框，用起来很方便，但就缺乏了自主性，eg

public class TestProgressMonitor { Timer timer; public void init() { final SimulatedTarget target = new SimulatedTarget(1000); //以启动一条线程的方式来执行一个耗时的任务 final Thread targetThread = new Thread(target); targetThread.start(); //创建进度对话框 final ProgressMonitor dialog = new ProgressMonitor(null , "等待任务完成" , "已完成：" , 0 , target.getAmount()); //创建一个计时器 timer = new Timer(300 , new ActionListener() { public void actionPerformed(ActionEvent e) { //以任务的当前完成量设置进度对话框的完成比例 dialog.setProgress(target.getCurrent()); //如果用户单击了进度对话框的”取消“按钮 if (dialog.isCanceled()) { //停止计时器 timer.stop(); //中断任务的执行线程 targetThread.interrupt(); //系统退出 System.exit(0); } } }); timer.start(); } public static void main(String[] args) { new TestProgressMonitor().init(); } }

这个程序利用了上面的耗时程序。进度条就是那么简单。

滑动条和进度条差不多，他们共用一个模型BoundedRangeModel。下面是个滑动条的各样式的演示例子，eg

public class TestJSlider { JFrame mainWin = new JFrame("滑动条示范"); Box sliderBox = new Box(BoxLayout.Y_AXIS); JTextField showVal = new JTextField(); ChangeListener listener; public void init() { //定义一个监听器，用于监听所有滑动条 listener = new ChangeListener() { public void stateChanged(ChangeEvent event) { //取出滑动条的值，并在文本中显示出来 JSlider source = (JSlider) event.getSource(); showVal.setText("当前滑动条的值为：" + source.getValue()); } }; //-----------添加一个普通滑动条----------- JSlider slider = new JSlider(); addSlider(slider, "普通滑动条"); //-----------添加保留区为30的滑动条----------- slider = new JSlider(); slider.setExtent(30); addSlider(slider, "保留区为30"); //-----------添加带主、次刻度的滑动条,并设置其最大值，最小值----------- slider = new JSlider(30 , 200); //设置绘制刻度 slider.setPaintTicks(true); //设置主、次刻度的间距 slider.setMajorTickSpacing(20); slider.setMinorTickSpacing(5); addSlider(slider, "有刻度"); //-----------添加滑块必须停在刻度处滑动条----------- slider = new JSlider(); //设置滑块必须停在刻度处 slider.setSnapToTicks(true); //设置绘制刻度 slider.setPaintTicks(true); //设置主、次刻度的间距 slider.setMajorTickSpacing(20); slider.setMinorTickSpacing(5); addSlider(slider, "滑块停在刻度处"); //-----------添加没有滑轨的滑动条----------- slider = new JSlider(); //设置绘制刻度 slider.setPaintTicks(true); //设置主、次刻度的间距 slider.setMajorTickSpacing(20); slider.setMinorTickSpacing(5); //设置不绘制滑轨 slider.setPaintTrack(false); addSlider(slider, "无滑轨"); //-----------添加方向反转的滑动条----------- slider = new JSlider(); //设置绘制刻度 slider.setPaintTicks(true); //设置主、次刻度的间距 slider.setMajorTickSpacing(20); slider.setMinorTickSpacing(5); //设置方向反转 slider.setInverted(true); addSlider(slider, "方向反转"); //-----------添加绘制默认刻度标签的滑动条----------- slider = new JSlider(); //设置绘制刻度 slider.setPaintTicks(true); //设置主、次刻度的间距 slider.setMajorTickSpacing(20); slider.setMinorTickSpacing(5); //设置绘制刻度标签，默认绘制数值刻度标签 slider.setPaintLabels(true); addSlider(slider, "数值刻度标签"); //-----------添加绘制Label类型的刻度标签的滑动条----------- slider = new JSlider(); //设置绘制刻度 slider.setPaintTicks(true); //设置主、次刻度的间距 slider.setMajorTickSpacing(20); slider.setMinorTickSpacing(5); //设置绘制刻度标签 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")); //指定刻度标签，标签是JLabel slider.setLabelTable(labelTable); addSlider(slider, "JLable标签"); //-----------添加绘制Label类型的刻度标签的滑动条----------- slider = new JSlider(); //设置绘制刻度 slider.setPaintTicks(true); //设置主、次刻度的间距 slider.setMajorTickSpacing(20); slider.setMinorTickSpacing(5); //设置绘制刻度标签 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"))); //指定刻度标签，标签是ImageIcon slider.setLabelTable(labelTable); addSlider(slider, "Icon标签"); mainWin.add(sliderBox, BorderLayout.CENTER); mainWin.add(showVal, BorderLayout.SOUTH); mainWin.pack(); mainWin.setVisible(true); } //定义一个方法，用于将滑动条添加到容器中 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(); } }