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JAVA 进度条
直接上官方示例
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.beans.*;
import java.util.Random;
public class ProgressBarDemo extends JPanel
implements ActionListener,
PropertyChangeListener {
private JProgressBar progressBar;
private JButton startButton;
private JTextArea taskOutput;
private Task task;
class Task extends SwingWorkerVoid, Void {
/*
* Main task. Executed in background thread.
*/
@Override
public Void doInBackground() {
Random random = new Random();
int progress = 0;
//Initialize progress property.
setProgress(0);
while (progress 100) {
//Sleep for up to one second.
try {
Thread.sleep(random.nextInt(1000));
} catch (InterruptedException ignore) {}
//Make random progress.
progress += random.nextInt(10);
setProgress(Math.min(progress, 100));
}
return null;
}
/*
* Executed in event dispatching thread
*/
@Override
public void done() {
Toolkit.getDefaultToolkit().beep();
startButton.setEnabled(true);
setCursor(null); //turn off the wait cursor
taskOutput.append("Done!n");
}
}
public ProgressBarDemo() {
super(new BorderLayout());
//Create the demo's UI.
startButton = new JButton("Start");
startButton.setActionCommand("start");
startButton.addActionListener(this);
progressBar = new JProgressBar(0, 100);
progressBar.setValue(0);
progressBar.setStringPainted(true);
taskOutput = new JTextArea(5, 20);
taskOutput.setMargin(new Insets(5,5,5,5));
taskOutput.setEditable(false);
JPanel panel = new JPanel();
panel.add(startButton);
panel.add(progressBar);
add(panel, BorderLayout.PAGE_START);
add(new JScrollPane(taskOutput), BorderLayout.CENTER);
setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
}
/**
* Invoked when the user presses the start button.
*/
public void actionPerformed(ActionEvent evt) {
startButton.setEnabled(false);
setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
//Instances of javax.swing.SwingWorker are not reusuable, so
//we create new instances as needed.
task = new Task();
task.addPropertyChangeListener(this);
task.execute();
}
/**
* Invoked when task's progress property changes.
*/
public void propertyChange(PropertyChangeEvent evt) {
if ("progress" == evt.getPropertyName()) {
int progress = (Integer) evt.getNewValue();
progressBar.setValue(progress);
taskOutput.append(String.format(
"Completed %d%% of task.n", task.getProgress()));
}
}
/**
* Create the GUI and show it. As with all GUI code, this must run
* on the event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("ProgressBarDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Create and set up the content pane.
JComponent newContentPane = new ProgressBarDemo();
newContentPane.setOpaque(true); //content panes must be opaque
frame.setContentPane(newContentPane);
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}
Java中如何实现进度条效果
import java.awt.Color; import java.awt.Toolkit; import javax.swing.ImageIcon; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JProgressBar; import javax.swing.JWindow; @SuppressWarnings("serial") public class Demo extends JWindow implements Runnable { // 定义加载窗口大小 public static final int LOAD_WIDTH = 455; public static final int LOAD_HEIGHT = 295; // 获取屏幕窗口大小 public static final int WIDTH = Toolkit.getDefaultToolkit().getScreenSize().width; public static final int HEIGHT = Toolkit.getDefaultToolkit().getScreenSize().height; // 定义进度条组件 public JProgressBar progressbar; // 定义标签组件 public JLabel label; // 构造函数 public Demo() { // 创建标签,并在标签上放置一张图片 label = new JLabel(new ImageIcon("images/background.jpg")); label.setBounds(0, 0, LOAD_WIDTH, LOAD_HEIGHT - 15); // 创建进度条 progressbar = new JProgressBar(); // 显示当前进度值信息 progressbar.setStringPainted(true); // 设置进度条边框不显示 progressbar.setBorderPainted(false); // 设置进度条的前景色 progressbar.setForeground(new Color(0, 210, 40)); // 设置进度条的背景色 progressbar.setBackground(new Color(188, 190, 194)); progressbar.setBounds(0, LOAD_HEIGHT - 15, LOAD_WIDTH, 15); // 添加组件 this.add(label); this.add(progressbar); // 设置布局为空 this.setLayout(null); // 设置窗口初始位置 this.setLocation((WIDTH - LOAD_WIDTH) / 2, (HEIGHT - LOAD_HEIGHT) / 2); // 设置窗口大小 this.setSize(LOAD_WIDTH, LOAD_HEIGHT); // 设置窗口显示 this.setVisible(true); } public static void main(String[] args) { Demo t = new Demo(); new Thread(t).start(); } @Override public void run() { for (int i = 0; i 100; i++) { try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); } progressbar.setValue(i); } JOptionPane.showMessageDialog(this, "加载完成"); this.dispose(); } }
java多线程导出如何更新进度条
1:一个子进程进行计算
2:计算过程中返回计算的百分比，比如10%，20%。。。。。100%；
3:前端需要一个定时器不断请求进度，然后更新进度条。