我有一个非常简单的动画,一个大字体的文字不断(逐个像素)移动到左边.首先将文本转换为图像,然后启动定时器任务,重复(每10-20 ms)将图像的x坐标递减1,并进行重绘().

这个程序在某些系统上显示出一个奇怪的行为.在带有nVidia卡的电脑上,它运行顺利.在我的Vaio笔记本上,在一个BeagleBoneBlack和一个朋友的Mac上,它沉重地放下.看起来暂停一段时间,然后向左移动约10个像素,再次暂停等等.

什么困扰我的事实是,在这些系统上,如果您没有触摸鼠标,动画只会停留.只要您将鼠标光标移动到窗口内,无论多么缓慢,或者拖动窗口本身,动画运行顺利！

有人可以解释一下吗这是程序：

import java.awt.*;

import java.awt.image.*;

import java.awt.event.*;

import javax.swing.*;

import java.io.*;

import java.util.*;

class Textimg extends JComponent

{

String str;

Font font;

int x = 0;

final int ytext = 136;

Image img;

public Textimg(String s)

{

str = s;

font = new Font("Noserif",Font.PLAIN,96);

setLayout(null);

}

protected void paintComponent(Graphics g)

{

if (img == null)

{

img = createImage(4800,272);

Graphics gr = img.getGraphics();

gr.setFont(font);

gr.setColor(Color.BLACK);

gr.fillRect(0,4800,272);

gr.setColor(new Color(135,175,0));

gr.drawString(str,ytext);

gr.dispose();

}

g.drawImage(img,x,this);

}

public void addX(int dif)

{

if (isVisible())

{

x = x + dif;

Graphics g = getGraphics();

if (g != null) paintComponent(g);

}

}

}

public class Banner extends JFrame

{

StringBuffer buf;

int sleeptime = 10;

Banner(String path) throws IOException

{

setSize(new Dimension(480,272));

setTitle("Java Test");

setDefaultCloSEOperation(EXIT_ON_CLOSE);

setLayout(null);

BufferedReader reader = new BufferedReader(

new InputStreamReader(new FileInputStream(path),"UTF-8"));

buf = new StringBuffer();

while (true)

{

String line = reader.readLine();

if (line == null) break;

buf.append(line);

}

final Textimg textimg = new Textimg(buf.toString());

add(textimg);

textimg.setBounds(0,480,272);

final javax.swing.Timer timer = new javax.swing.Timer(200,new ActionListener()

{

public void actionPerformed(ActionEvent e)

{

textimg.addX(-1);

}

});

timer.setDelay(sleeptime);

timer.start();

}

//----------------------------------------------------------------------

public static void main(String[] args) throws Exception

{

new Banner(args[0]).setVisible(true);

}

}