Question

java双缓冲问题！！

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;

import javax.swing.JFrame;

public class zy23_1 extends JFrame{
BufferedImage x=null;
Graphics g1=null;
Image age=null;
Image age1=null;
Toolkit t1=null;
int i=0;
zy23_1()
{
A a=new A();
a.start();
x=new BufferedImage(400,400,BufferedImage.TYPE_INT_RGB);
g1=x.getGraphics();
t1=Toolkit.getDefaultToolkit();
age=t1.createImage("22.gif");
age1=t1.createImage("22.JPG");
this.setBounds(200,200,202,154);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setVisible(true);
}
public void paint(Graphics g)
{
g1.setColor(this.getBackground());
g1.fillRect(0,0,202,154);
g.drawImage(age1,0,0,200,150,i,96,96,i,this);
g.drawImage(age,0,0,200,150,0,0,200,150,this);
}
public static void main(String[] args) {
new zy23_1();
}
class A extends Thread
{
public void run()
{
while(true){
try {
sleep(10);
} catch (InterruptedException e) {
e.printStackTrace();
}
i++;
repaint();
if(i>=96) i=0;
}
}
}
}

我运行时图片还是会不停的闪烁，我已经做了双缓冲。哪里出问题了？？懂的朋友请讲解下！谢谢

Answer 1

paint()方法中其实并未实现双缓冲，双缓冲是在后台虚拟的Image中绘制完成后再返回当前窗口，而这个代码直接调用g进行两次drawImage，其实就是直接对当前窗口进行绘制，有覆盖区域，会产生闪烁，，按照下列修改paint()方法就可以了

public void paint(Graphics g) {
g1.setColor(this.getBackground());
g1.fillRect(0,0,202,154);
g1.drawImage(age1,0,0,200,150,i,96,96,i,this);
g1.drawImage(age,0,0,200,150,0,0,200,150,this);
g.drawImage(x,0,0,this); //把x图像返回到当前窗口
}

Answer 2

双缓冲的概念你还没搞清楚 你那样是同时画2张图片 重写update方法 把缓冲图画在update里面 然后再画到paint里面 PS：调用repaint方法会先调用update方法