我用Canvas画布屏幕设计来图形动画出现了错误，希望看看错在哪里？代码如下
import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;
import javax.microedition.lcdui.*;
public class showpicture extends MIDlet implements CommandListener{
public Display display;
private Mycanvas mycanvas;
private Command cmd_exit;
public showpicture() {
display=Display.getDisplay(this);
cmd_exit=new Command("Exit",Command.EXIT,1);
mycanvas = new Mycanvas();
mycanvas.addCommand(cmd_exit);
mycanvas.setCommandListener(this);
}
protected void destroyApp(boolean arg0) {
// TODO 自动生成方法存根
}
protected void pauseApp() {
// TODO 自动生成方法存根
}
protected void startApp() {
display.setCurrent(mycanvas);
Thread tr=new Thread(mycanvas);
tr.start();
}
public void commandAction(Command arg0, Displayable arg1) {
if(arg0==cmd_exit)
{
destroyApp(false);
notifyDestroyed();
}
}
}
class Mycanvas extends Canvas implements Runnable{
private Image image[]=new Image[5];
private int currentFrame=0;
private Display display;
public Mycanvas()
{
try{
for(int i=0;i<5;i++)
{
image[i]=Image.createImage("/"+i+".jpeg");
}
}catch(Exception e){}
currentFrame=0;
}
protected void paint(Graphics g) {
g.setColor(255, 255, 255);
g.fillRect(0,0, getWidth(),getHeight());
g.drawImage(image[currentFrame], getWidth()/2,getHeight()/2, g.HCENTER|g.VCENTER);
}
public void run() {
try{
Thread.sleep(200);
currentFrame=(currentFrame+1)%5;
repaint();
display.callSerially(this);
}catch(Exception ce){}
}
}
错误为：
java.lang.NullPointerException:
at Mycanvas.paint(+59)
at javax.microedition.lcdui.Canvas.callPaint(+85)
at javax.microedition.lcdui.Display.repaint(+82)
at javax.microedition.lcdui.Display.registerNewCurrent(+235)
at javax.microedition.lcdui.Display.access$700(+6)
at javax.microedition.lcdui.Display$DisplayAccessor.foregroundNotify(+46)
at javax.microedition.lcdui.Display$DisplayManagerImpl.notifyWantsForeground(+152)
at javax.microedition.lcdui.Display$DisplayManagerImpl.access$100(+6)
at javax.microedition.lcdui.Display.setCurrent(+70)
at showpicture.startApp(+11)
at javax.microedition.midlet.MIDletProxy.startApp(+7)
at com.sun.midp.midlet.Scheduler.schedule(+270)
at com.sun.midp.main.Main.runLocalClass(+28)
at com.sun.midp.main.Main.main(+80)
java.lang.NullPointerException:
at Mycanvas.paint(+59)
at javax.microedition.lcdui.Canvas.callPaint(+85)
at javax.microedition.lcdui.Display.repaint(+82)
at javax.microedition.lcdui.Display$DisplayAccessor.repaint(+14)
at javax.microedition.lcdui.Display$DisplayManagerImpl.repaint(+16)
at com.sun.midp.lcdui.DefaultEventHandler.repaintScreenEvent(+24)
at com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.run(+519)
Execution completed.
------解决方案--------------------------------------------------------
看看创建图片有没有错误.捕获一下.应该是画图片的时候报的空指针
------解决方案--------------------------------------------------------
应该是这个模拟器不支持jpeg格式吧
------解决方案--------------------------------------------------------
package core;
import javax.microedition.lcdui.Canvas;