Android ViewPager 监听滑动

 vp.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {            @Override            public void onPageSelected(int arg0) {                switch (arg0) {                    case 0:                                                break;                    case 1:                                               break;                    case 2:                                                break;                }            }            @Override            public void onPageScrolled(int arg0, float arg1, int arg2) {            }            @Override            public void onPageScrollStateChanged(int arg0) {            }        });