ainActivity.java 重要 程式碼

public class MainActivity extends Activity{

private Thread thread1;

private Thread thread2;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

final FrameLayout frame=new FrameLayout(this);

setContentView(frame);

frame.findViewById(R.id.framelayout1);

final MyView view=new MyView(this);

thread1=new Thread(new Runnable(){

@Override

public void run(){

view.setOnTouchListener(new OnTouchListener(){

@Override

public boolean onTouch(View v,MotionEvent event){

++view.r;

view.invalidate();

return true;

}

});

}

});

thread2=new Thread(new Runnable(){

@Override

public void run(){

--view.r;

view.invalidate();

try {

Thread.sleep(100);

} catch (InterruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

});

thread1.start();

thread2.start();

frame.addView(view);

if (view.r==1)

{

thread2.interrupt();

}

if (view.r==100){

thread1.interrupt();

}

}

}

class MyView extends View{

int r=10,x,y;

public MyView(Context context){

super(context);

x=context.getResources().getDisplayMetrics().widthPixels/2;

y=context.getResources().getDisplayMetrics().heightPixels/2;

}

@Override

protected void onDraw(Canvas canvas){

super.onDraw(canvas);

canvas.drawColor(Color.WHITE);

Paint paint=new Paint();

paint.setAntiAlias(true);

paint.setStrokeWidth(3);

paint.setStyle(Style.STROKE);

paint.setColor(Color.BLUE);

canvas.drawCircle(x,y,r,paint);

}

}