select some frames from a animation-list by using reflection（使用反射从动画列表里选择几个图片来显示）

select some frames from a animation-list by using reflection

        imageView = (ImageView) findViewById(R.id.myImageview);
        small_imageView = (ImageView) findViewById(R.id.small_image);
        imageView.setBackgroundResource(R.anim.m_anim);
        animationDrawable = (AnimationDrawable) imageView.getBackground();
        
    public void start(View view) {   //A button click
        if (!animationDrawable.isRunning()) {
            animationDrawable.start();
            controlFrame = new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        Field field = AnimationDrawable.class.getDeclaredField("mCurFrame");
                        field.setAccessible(true);
                        while (true) {
                            int currentFrame = field.getInt(animationDrawable);
                            if (currentFrame == 2 || currentFrame == 3) {
                                field.setInt(animationDrawable, 4);
                            }
                        }
                    } catch (Exception e) {
                        Log.e("ERROR", e.getMessage());
                    }
                }
            });
            controlFrame.start();
        } else {
            try {
                controlFrame.interrupt();

            } catch (Exception e) {
                Log.i("Thread Stop Exception", e.getMessage());
            }
            animationDrawable.stop();
////            int number = animationDrawable.getNumberOfFrames();
////            int duration = animationDrawable.getDuration(1);
//            Drawable drawable = animationDrawable.getCurrent();
//            int len = animationDrawable.getNumberOfFrames();
//            long currentTime1=System.nanoTime();
//            for (int i = 0; i < len; i++) {   //7ms ~ 12ms 运行时间
//                if (animationDrawable.getFrame(i).equals(animationDrawable.getCurrent())) {
//                    Toast.makeText(this, i+"", Toast.LENGTH_LONG).show();
//                    small_imageView.setImageDrawable(animationDrawable.getCurrent());
//                }
//            }
//            long currentTime2=System.nanoTime();
//            Log.i("eclipseTime",currentTime2-currentTime1+"");
////            small_imageView.setImageDrawable(drawable);
////            Toast.makeText(this, number + " " + duration, Toast.LENGTH_LONG).show();
        }

    }