总结：运用JProgressBar类。还有线程相关

package com.v;import java.awt.image.*;import java.awt.Color;import java.awt.Dimension;import java.awt.Toolkit;import java.awt.FlowLayout;import javax.swing.ImageIcon;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JProgressBar;import javax.swing.JWindow;import java.awt.event.*;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_high = 295;	public static final int width = Toolkit.getDefaultToolkit().getScreenSize().width;	public static final int high = Toolkit.getDefaultToolkit().getScreenSize().height;	// 定义进度条组件@Override	public JProgressBar progressbar;	// 定义标签组件	public JLabel label;	// 构造方法	public Demo() {		// /创建标签并在表标签上放一个图片		label = new JLabel(new ImageIcon("images/background.jpg"));//		// label=new JLabel();//这里理解关键		label.setBounds(0, 0, load_width, load_high - 15);		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_high - 15, load_width, 15);// 这一步我漏掉了导致进程条不显示		// 添加标签		this.add(label);		// 添加进程条		this.add(progressbar);		// 设置窗口的大小		this.setSize(load_width, load_high);		// 设置窗口的初始位置		this.setLocation((high - load_high) / 2, (width - load_width) / 2);		// 设置窗体的布局		this.setLayout(null);		// this.setLayout(new FlowLayout());		// 设置窗口在屏幕中央显示		this.setLocationRelativeTo(null);		// 设置窗口显示		this.setVisible(true);	}	public static void main(String[] args) {		Demo demo = new Demo();// 创建对象		new Thread(demo).start();	}	public void run() {		for (int i = 0; i <= 100; i++) {			try {				Thread.sleep(100);// 线程			} catch (InterruptedException I) {				I.printStackTrace();			}			progressbar.setValue(i);		}		JOptionPane.showMessageDialog(this, "OK任务已完成！");		this.dispose();	}}