ViewPager轮播图引导页

创建fragment将fragment对象添加到viewPager中，使其可以进行左右滑动的功能

  fragmentList.add(new Fragment1());
        fragmentList.add(new Fragment2());
        fragmentList.add(new Fragment3());
        FragAdapter fragAdapter = new FragAdapter(getSupportFragmentManager(), fragmentList);
        
        vp.setAdapter(fragAdapter);

实现跟随页面滑动的小圆点,小圆点颜色跟着变化

   final List<ImageView> imglist = new ArrayList<>();
        
        for (int i = 0; i < fragmentList.size(); i++) {
            ImageView imageView = new ImageView(this);
            if (i == 0){
                imageView.setImageResource(R.drawable.t);
            }else {
                imageView.setImageResource(R.drawable.f);
            }
            imageView.setPadding(20,0,0,0);
            ll.addView(imageView);
            imglist.add(imageView);
        }
        vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                for (int i = 0; i < imglist.size() ; i++) {
                    if (position == i){
                        imglist.get(i).setImageResource(R.drawable.t);
                    }else {
                        imglist.get(i).setImageResource(R.drawable.f);
                    }
                }
            }
            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

手动搞一个小圆点选择器

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval">
<solid android:color="#03A9F4"></solid>
<size android:height="10dp" android:width="10dp"></size>
</shape>

<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="oval">
    <solid android:color="#929597"></solid>
    <size android:height="10dp" android:width="10dp"></size>
</shape>

当viewPager滑动到最后一页时,实现倒计时跳转的功能(好几种方式,这个是最简单)

//在主页面写一个Textview,当滑动到最后一页时,让他开始实现倒计时
  vp.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                if (position == fragmentList.size()-1){
                    Timer timer = new Timer();
                    timer.schedule(new TimerTask() {
                        @Override
                        public void run() {
                            index--;
                            runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    txt.setText("倒计时"+index);
                                    if (index == 0){
                                        Intent intent = new Intent(WelcomeActivity.this, MainActivity.class);
                                        startActivity(intent);
                                    }
                                }
                            });
                        }
                    },0,1000);
                }
            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });