一个进度条的例子

 

import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.*;

public class MyJProgressBar implements ActionListener
{
JFrame f = null;

JProgressBar progressbar;

JLabel label;

Timer timer;

JButton b,stop;

public MyJProgressBar() {
f = new JFrame("ProgressBar Example");
Container contentPane = f.getContentPane();

label = new JLabel(" ", JLabel.CENTER); // 文本居中显示
progressbar = new JProgressBar();
progressbar.setOrientation(JProgressBar.HORIZONTAL); //进度条的滚动方向，必须为（JProgressBar.VERTICAL 或 JProgressBar.HORIZONTAL）
progressbar.setMinimum(0); // 设置进度条的最小值
progressbar.setMaximum(200); // 设置进度条的最大值
progressbar.setValue(0); // 设置进度条的值
progressbar.setStringPainted(true); // 进度文本10%
progressbar.setPreferredSize(new Dimension(200, 20)); // 设置进度条的长，高
progressbar.setBorderPainted(true); //设置进度条边框是否显示
progressbar.setBackground(Color.white); //设置进度条的背景色

JPanel panel = new JPanel();
b = new JButton("Start");
b.setForeground(Color.blue);
b.addActionListener(this);
panel.add(b);

stop = new JButton("stop");
stop.setForeground(Color.blue);
stop.addActionListener(this);
panel.add(stop);

timer = new Timer(100, this);

contentPane.add(panel, BorderLayout.NORTH);
contentPane.add(progressbar, BorderLayout.CENTER);
contentPane.add(label, BorderLayout.SOUTH);

f.pack(); // 调整此窗口的大小，以适合其子组件的首选大小和布局。
f.setVisible(true);

f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0); //JVM也退出
}
});
}

public static void main(String[] args) {
new MyJProgressBar();
}

public void actionPerformed(ActionEvent e) {
if (e.getSource() == b) {
timer.start();
}

if (e.getSource() == stop) {
timer.stop();
}

if (e.getSource() == timer) {
int value = progressbar.getValue();

if (value < 200) {
value++;
progressbar.setValue(value);
} else {
timer.stop();
Double dValue = new Double(200.0f);
System.out.println(dValue);
}

}
}

}