引导页底部带点的

代码

public class MainActivity extends AppCompatActivity {

    private ViewPager viewpager;
    private LinearLayout linear;
    private Button button;
    private int[] resimage = {R.mipmap.mg3, R.mipmap.mg4, R.mipmap.mg5};
    private List<ImageView> imagelist;
    private List<ImageView> dotlist;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
        initData();
        initAdapter();
        initListener();

    }

    private void initListener() {
        viewpager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                for (int i = 0; i < 3; i++) {
                    if(position==i){
                        dotlist.get(i).setImageResource(R.drawable.selectdot);
                    }else{
                        dotlist.get(i).setImageResource(R.drawable.normaldot);
                    }

                    if(position==imagelist.size()-1){
                        button.setVisibility(View.VISIBLE);
                        linear.setVisibility(View.GONE);
                    }else{
                        button.setVisibility(View.GONE);
                        linear.setVisibility(View.VISIBLE);
                    }
                }

            }

            @Override
            public void onPageScrollStateChanged(int state) {

            }
        });

    }

    private void initAdapter() {
        MyAdapter myAdapter = new MyAdapter(imagelist);
        viewpager.setAdapter(myAdapter);
    }

    private void initData() {

        imagelist = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
            ImageView imageView = new ImageView(this);
            imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
            imageView.setImageResource(resimage[i]);
            imagelist.add(imageView);
        }

        dotlist = new ArrayList<>();
        for (int i = 0; i < 3; i++) {

            ImageView imageView = new ImageView(this);
            LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
            params.leftMargin = 10;
            params.rightMargin = 10;
            params.width = 30;
            params.height = 30;

            imageView.setLayoutParams(params);
            if (i == 0) {
                imageView.setImageResource(R.drawable.selectdot);
            } else {
                imageView.setImageResource(R.drawable.normaldot);
            }
            dotlist.add(imageView);

            linear.addView(imageView);
        }

    }

    private void initView() {
        viewpager = (ViewPager) findViewById(R.id.viewpager);
        linear = (LinearLayout) findViewById(R.id.linear);
        button = (Button) findViewById(R.id.btn_enter);
    }
}

适配器

public class MyAdapter  extends PagerAdapter {

    private List<ImageView>  imagelist;

    public MyAdapter(List<ImageView> imagelist) {
        this.imagelist = imagelist;
    }

    @Override
    public int getCount() {
        return imagelist.size();
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view==object;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
//        super.destroyItem(container, position, object);
        container.removeView(imagelist.get(position));
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        container.addView(imagelist.get(position));
        return imagelist.get(position);
    }
}

drawable里面写

《selectdot》

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval">
    <corners android:radius="30dp" />
    <solid android:color="#fc05a9" />
</shape>

《normaldot》

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="oval"
    >
    <corners android:radius="30dp" />
    <solid android:color="#d1d1d1" />

</shape>

xml里面写

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.day09viewpagercircle.MainActivity">

    <android.support.v4.view.ViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"></android.support.v4.view.ViewPager>

    <LinearLayout
        android:id="@+id/linear"
        android:layout_width="match_parent"
        android:layout_height="54dp"
        android:orientation="horizontal"
        android:layout_gravity="bottom"
        android:background="#00acff"></LinearLayout>

<Button
    android:visibility="gone"
    android:layout_gravity="bottom"
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="立即体验"
    android:id="@+id/btn_enter"
    />
</FrameLayout>