java画图中运用缓冲解决屏幕闪烁方案二

import javax.microedition.midlet.*;

import javax.microedition.lcdui.*;

public class BufferDrawExample extends MIDlet

{

  private Display  display;       

  private MyCanvas canvas;   

  public BufferDrawExample()

  {

//获取MIDlet的Display对象实例

    display = Display.getDisplay(this);

//声明Canvas屏幕对象

    canvas  = new MyCanvas (this);

  }

  protected void startApp()

  {

//显示屏幕对象

    display.setCurrent(canvas);

  }

  protected void pauseApp()

  { 

  }

  protected void destroyApp( boolean unconditional )

  { 

  }

  public void exitMIDlet()

  {

    destroyApp(true);

    notifyDestroyed();

  }

}

class MyCanvas extends Canvas implements CommandListener

{

  private Command exit;

  //声明图片对象

  private Image image;

  //声明作为缓冲区的可变图像对象

  private Image buffer;

  private BufferDrawExample bufferDrawExample;

  public MyCanvas (BufferDrawExample bufferDrawExample)

  {

this.bufferDrawExample = bufferDrawExample;

    exit = new Command("Exit", Command.EXIT, 1);

    addCommand(exit);

    setCommandListener(this);

try

{

//获得图像文件

image = Image.createImage("/12.png");    

}

catch (Exception e)

{

System.out.println(e);

}

//创建可变图像

buffer=Image.createImage(getWidth(),getHeight());

//获取缓冲区的Graphics对象

Graphics graphics=buffer.getGraphics();