求教：如何在JWindow上显示滚动字幕

Question

笨辦法，用timer設定定時，設定不同時間字幕的不同位置~~~

Answer 1

marquee是IE专用的，html中好像还没有标准的滚动字幕的标签。
用个线程算了，不麻烦。

Answer 2

一般就是用一个线程来控制显示一个Label

Answer 3

JTextPane只对部分HTML支持，连CSS,JavaScript都不能正确显示
你自己弄个Timer控制吧

Answer 4

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.awt.image.*;public class ScrollText extends JComponent
{
private BufferedImage image;
private Dimension imageSize;
private volatile int currOffset;

private Thread internalThread;
private volatile boolean noStopRequested;

public ScrollText(String text)
{
currOffset=0;
buildImage(text);

this.setMinimumSize(imageSize);
this.setPreferredSize(imageSize);
this.setMaximumSize(imageSize);
this.setSize(imageSize);

noStopRequested=true;
Runnable r=new Runnable()
{
public void run()
{
try
{
runWork();
}
catch(Exception e)
{
e.printStackTrace();
}
}
};

internalThread=new Thread(r,"ScrollText");
internalThread.start();
}

private void buildImage(String text)
{
//请求绘制时，打开反锯齿，并运用高质量选项
RenderingHints renderHints=new RenderingHints(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
renderHints.put(RenderingHints.KEY_RENDERING,RenderingHints.VALUE_RENDER_QUALITY);

//创建一幅临时图像，用于判断文件的大小
BufferedImage scratchImage=new BufferedImage(1,1,BufferedImage.TYPE_INT_RGB);

Graphics2D scratchG2=scratchImage.createGraphics();
scratchG2.setRenderingHints(renderHints);

Font font=new Font("Serif",Font.BOLD|Font.ITALIC,24);

FontRenderContext frc=scratchG2.getFontRenderContext();
TextLayout t1=new TextLayout(text,font,frc);
Rectangle2D textBounds=t1.getBounds();
int textWidth=(int)Math.ceil(textBounds.getWidth());
int textHeight=(int)Math.ceil(textBounds.getHeight());
int horizontalPad=10;
int verticalPad=6;

imageSize=new Dimension(textWidth+horizontalPad,textHeight+verticalPad);

//创建适当大小的图像
image=new BufferedImage(imageSize.width,imageSize.height,BufferedImage.TYPE_INT_RGB);

Graphics2D g2=image.createGraphics();
g2.setRenderingHints(renderHints);

int baselineOffset=(verticalPad/2)-((int)textBounds.getY());

g2.setColor(Color.white);
g2.fillRect(0,0,imageSize.width,imageSize.height);

g2.setColor(Color.blue);
t1.draw(g2,0,baselineOffset);

//立即释放资源，但保持动画显示图像
scratchG2.dispose();
scratchImage.flush();
g2.dispose();
}

public void paint(Graphics g)
{
//不论当前大小，确保裁减边缘
g.setClip(0,0,imageSize.width,imageSize.height);

int localOffset=currOffset; //以防改变
g.drawImage(image,-localOffset,0,this);
g.drawImage(image,imageSize.width-localOffset,0,this);

//绘制轮廓
g.setColor(Color.black);
g.drawRect(0,0,imageSize.width-1,imageSize.height-1);
}

private void runWork()
{
while(noStopRequested)
{
try
{
Thread.sleep(100); //每秒10帧

//调整滚动位置
currOffset=(currOffset+1)%imageSize.width;

//通知事件线程调用paint()
repaint();
}
catch(InterruptedException e)
{
Thread.currentThread().interrupt();
}
}
}

public void stopRequest()
{
noStopRequested=false;
internalThread.interrupt();
}

public boolean isAlive()
{
return internalThread.isAlive();
}

public static void main(String args[])
    {
     ScrollText st=new ScrollText("Java can do animation!");
     JPanel p=new JPanel(new FlowLayout());
     p.add(st);
    
     JFrame f=new JFrame("ScrollText Demo");
     f.setContentPane(p);
     f.setSize(400,100);
     f.setVisible(true);
    }
  }