Swing JProgressBar

JProgressBar类是一个组件，它可视地显示某些任务的进度。

类声明

以下是声明 javax.swing.JProgressBar类：

public class JProgressBar
   extends JComponent
      implements SwingConstants, Accessible

字段域

以下是javax.swing.JProgressBar类的字段域：

protected ChangeEvent changeEvent --因为事件的唯一有趣的属性是不可改变的源，这是进度条，需要每个实例只有一个ChangeEvent事件。
protected ChangeListener changeListener --监听发送进度条的模型的变化事件，他们重新调度变更登记的的事件监听器后。
protected BoundedRangeModel model --对象保存数据进度条。
protected int orientation --无论是进度条是水平或垂直。
protected boolean paintBorder --是否显示进度条周围的边框。
protected boolean paintString --无论在进度条上显示的文本字符串。
protected String progressString --可以在进度条上显示的可选字符串。

类构造函数

S.N.	构造函数 & 描述
1	JProgressBar() Creates a horizontal progress bar that displays a border but no progress string.
2	JProgressBar(BoundedRangeModel newModel) Creates a horizontal progress bar that uses the specified model to hold the progress bar's data.
3	JProgressBar(int orient) Creates a progress bar with the specified orientation, which can be either SwingConstants.VERTICAL or SwingConstants.HORIZONTAL.
4	JProgressBar(int min, int max) Creates a horizontal progress bar with the specified minimum and maximum.
5	JProgressBar(int orient, int min, int max) Creates a progress bar using the specified orientation, minimum, and maximum.

类方法

S.N.	方法 & 描述
1	void addChangeListener(ChangeListener l) Adds the specified ChangeListener to the progress bar.
2	protected ChangeListener createChangeListener() Subclasses that want to handle change events from the model differently can override this to return an instance of a custom ChangeListener implementation.
3	protected void fireStateChanged() Send a ChangeEvent, whose source is this JProgressBar, to all ChangeListeners that have registered interest in ChangeEvents.
4	AccessibleContext getAccessibleContext() Gets the AccessibleContext associated with this JProgressBar.
5	ChangeListener[] getChangeListeners() Returns an array of all the ChangeListeners added to this progress bar with addChangeListener.
6	int getMaximum() Returns the progress bar's maximum value from the BoundedRangeModel.
7	int getMinimum() Returns the progress bar's minimum value from the BoundedRangeModel.
8	BoundedRangeModel getModel() Returns the data model used by this progress bar.
9	int getOrientation() Returns SwingConstants.VERTICAL or SwingConstants.HORIZONTAL, depending on the orientation of the progress bar.
10	double getPercentComplete() Returns the percent complete for the progress bar.
11	String getString() Returns a String representation of the current progress.
12	ProgressBarUI getUI() Returns the look-and-feel object that renders this component.
13	String getUIClassID() Returns the name of the look-and-feel class that renders this component.
14	int getValue() Returns the progress bar's current value from the BoundedRangeModel.
15	boolean isBorderPainted() Returns the borderPainted property.
16	boolean isIndeterminate() Returns the value of the indeterminate property.
17	boolean isStringPainted() Returns the value of the stringPainted property.
18	protected void paintBorder(Graphics g) Paints the progress bar's border if the borderPainted property is true.
19	protected String paramString() Returns a string representation of this JProgressBar.
20	void removeChangeListener(ChangeListener l) Removes a ChangeListener from the progress bar.
21	void setBorderPainted(boolean b) Sets the borderPainted property, which is true if the progress bar should paint its border.
22	void setIndeterminate(boolean newValue) Sets the indeterminate property of the progress bar, which determines whether the progress bar is in determinate or indeterminate mode.
23	void setMaximum(int n) Sets the progress bar's maximum value (stored in the progress bar's data model) to n.
24	void setMinimum(int n) Sets the progress bar's minimum value (stored in the progress bar's data model) to n.
25	void setModel(BoundedRangeModel newModel) Sets the data model used by the JProgressBar.
26	void setOrientation(int newOrientation) Sets the progress bar's orientation to newOrientation, which must be SwingConstants.VERTICAL or SwingConstants.HORIZONTAL.
27	void setString(String s) Sets the value of the progress string.
28	void setStringPainted(boolean b) Sets the value of the stringPainted property, which determines whether the progress bar should render a progress string.
29	void setUI(ProgressBarUI ui) Sets the look-and-feel object that renders this component.
30	void setValue(int n) Sets the progress bar's current value to n.
31	void updateUI() Resets the UI property to a value from the current look and feel.

方法继承

这个类从以下类继承的方法：

javax.swing.JComponent
java.awt.Container
java.awt.Component
java.lang.Object

JProgressBar 例子

选择使用任何编辑器创建以下java程序在 D:/ > SWING > com > yiibai > gui >

SwingControlDemo.java

package com.yiibai.gui;
 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
public class SwingControlDemo {
    
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel;

   public SwingControlDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      SwingControlDemo  swingControlDemo = new SwingControlDemo();      
      swingControlDemo.showProgressBarDemo();
   }

   private void prepareGUI(){
      mainFrame = new JFrame("Java Swing Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      headerLabel = new JLabel("", JLabel.CENTER);        
      statusLabel = new JLabel("",JLabel.CENTER);    

      statusLabel.setSize(350,100);

      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }

   private JProgressBar progressBar;
   private Task task;
   private JButton startButton;
   private JTextArea outputTextArea;
   
   private void showProgressBarDemo(){
      headerLabel.setText("Control in action: JProgressBar"); 

      progressBar = new JProgressBar(0, 100);
      progressBar.setValue(0);
      progressBar.setStringPainted(true);
      startButton = new JButton("Start");

      outputTextArea = new JTextArea("",5,20);

      JScrollPane scrollPane = new JScrollPane(outputTextArea);    
         startButton.addActionListener(new ActionListener() {
         @Override
         public void actionPerformed(ActionEvent e) {
            task = new Task();                
            task.start();
         }});

      controlPanel.add(startButton);
      controlPanel.add(progressBar);
      controlPanel.add(scrollPane);
      mainFrame.setVisible(true);  
   }

   private class Task extends Thread {    
      public Task(){
      }

      public void run(){
         for(int i =0; i<= 100; i+=10){
            final int progress = i;
            SwingUtilities.invokeLater(new Runnable() {
               public void run() {
                  progressBar.setValue(progress);
                  outputTextArea.setText(outputTextArea.getText() 
                  + String.format("Completed %d%% of task.
", progress));
               }
            });
            try {
               Thread.sleep(100);
            } catch (InterruptedException e) {}
         }
      }
   }   
}

编译程序，使用命令提示符。到 D:/ > SWING 然后输出以下命令。

D:SWING>javac comyiibaiguiSwingControlDemo.java

如果没有错误出现，这意味着编译成功。使用下面的命令来运行程序。

D:SWING>java com.yiibai.gui.SwingControlDemo

验证下面的输出