Question

用 java 怎么做进度条？

Answer 1

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;

public class MyProgressBar extends Canvas {
private float scaleSize;
private float currentValue;

public MyProgressBar() {
this(100, 50);
}

public MyProgressBar(float scaleSize, float currentValue) {
this.scaleSize = scaleSize;
this.currentValue = currentValue;

this.setBackground(Color.lightGray);
this.setForeground(Color.magenta);
setSize(150, 25);
}

public float getCurrentValue() {
return currentValue;
}

public void setCurrentValue(float currentValue) {
this.currentValue = Math.max(0, currentValue);
if (this.scaleSize < this.currentValue) {
this.currentValue = this.scaleSize;
}
}

public float getScaleSize() {
return scaleSize;
}

public void setScaleSize(float scaleSize) {
this.scaleSize = Math.max(1.0f, scaleSize);
if (this.scaleSize < this.currentValue) {
this.scaleSize = this.currentValue;
}
}

public synchronized void paint(Graphics g) {
int w = getSize().width;
int h = getSize().height;

g.setColor(getBackground());
g.fillRect(1, 1, w - 2, h - 2);
g.fill3DRect(0, 0, w - 1, h - 1, true);

g.setColor(getForeground());
g.fillRect(3, 3, (int) (currentValue * (w - 6) / scaleSize), h - 6);
}
}

下面是程序执行入口点：
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;

public class TestMyProgressBar extends JFrame implements Runnable,
ActionListener {

private MyProgressBar bar;
private JButton btnStart;
static TestMyProgressBar tmpb;

public TestMyProgressBar() {
setSize(400, 300);
setLocation(400, 400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setTitle("演示自定义进度条");
setLayout(new FlowLayout());
btnStart = new JButton("开始");
this.add(btnStart);
btnStart.addActionListener(this);
bar = new MyProgressBar();
setVisible(true);
}

public static void main(String[] args) {
tmpb = new TestMyProgressBar();
}

@Override
public void run() {
for (int i = 1; i <= 20; i++) {
int x = i * 5;
bar.setCurrentValue(x);
if (x > 0 && x < 100) {
btnStart.setEnabled(false);
}
if (x == 100) {
btnStart.setEnabled(true);
}
try {
Thread.sleep(200);
add(bar);

} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

@Override
public void actionPerformed(ActionEvent e) {
if (e.getActionCommand().equals("开始")) {
Thread t = new Thread(tmpb);
t.start();
}
}
}

追问

这不是我想要的，要让它自动起动，自动消失。

追答

那样的话 你可以自己写个 啊
难道别人帮你做成现成的
你拿过去就用
这未必就有点太懒了吧

Answer 2

用servlet吧，网上有很多！