日期:2014-05-20  浏览次数:20836 次

处理Applet闪烁问题
这是我的代码

public class myapplet extends Applet {

public void paint(Graphics g) {

Date date=new Date();
g.drawString(date.toString(),20,50);
repaint(1000);
}
public void update(Graphics g){ paint(g); } 
}

重写update解决了闪烁问题 但是画面没有刷新 新的画面和原先的都重叠在一起了 请问怎么解决啊?

------解决方案--------------------
用双缓冲

import java.applet.*;
import java.util.*;
import java.awt.*;

public class myapplet extends Applet 

private Image bgImage;
private Graphics bg;

public void paint(Graphics g) 

Date date=new Date(); 
g.drawString(date.toString(),20,50); 
repaint(1000); 
}
 
public void update (Graphics g)
{
if (bgImage == null)
{
bgImage = createImage (this.getSize().width, this.getSize().height);
bg = bgImage.getGraphics ();
}
bg.setColor (getBackground ());
bg.fillRect (0, 0, this.getSize().width, this.getSize().height);
bg.setColor (getForeground());
paint (bg);
g.drawImage (bgImage, 0, 0, this);
}

}
------解决方案--------------------
参考这个:在 paint 里调用 repaint(1000) AWT 线程得忙死。
Java code
import java.util.Date;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.awt.Font;
import java.awt.BorderLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseAdapter;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;

/**
 * TimerFrame - 倒计时窗口
 * @author SageZk
 * @version 1.0
 */
@SuppressWarnings("serial")
public class TimerFrame extends JFrame {

    private long time = (long) (1.2 * 60 * 1000L);  //倒计时时间(单位毫秒)
    private JLabel lblTime;
    private Thread runner;

    public TimerFrame() {
        super("TimerFrame");
        this.lblTime = new JLabel("单击开始");
        this.lblTime.setFont(new Font("Monospaced", Font.BOLD, 60));
        this.lblTime.setHorizontalAlignment(SwingConstants.CENTER);
        this.lblTime.addMouseListener(new MouseAdapter() {
            public void mouseClicked(MouseEvent e) {
                if (runner != null) runner.start();
            }
        });
        this.runner = new Thread(new Runnable() {
            public void run() {
                Date t = new Date();
                StringWriter sw = new StringWriter();
                StringBuffer sb = sw.getBuffer();
                PrintWriter pw = new PrintWriter(sw);
                long cur = 0L, end = System.currentTimeMillis() + time;
                while ((cur = end - System.currentTimeMillis()) > 0) {
                    t.setTime(cur);
                    pw.format("%1$tM:%1$tS.%tL", t);
                    pw.flush();
                    lblTime.setText(sb.toString());
                    sb.setLength(0);
                    try {
                        Thread.sleep(6L);
                    } catch (InterruptedException e) {
                    }
                }
                lblTime.setText("00:00.000");
                try {
                    Thread.sleep(1200L);
                } catch (InterruptedException e) {
                }
                lblTime.setText("Bomb!!!");
            }
        });
        this.runner.setDaemon(true);
        getContentPane().add(this.lblTime, BorderLayout.CENTER);
        setResizable(false);
        setBounds(0, 0, 460, 330);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        new TimerFrame().setVisible(true);
    }

}