引导页 布局配置

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

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

    </android.support.v4.view.ViewPager>



    <RadioGroup
        android:id="@+id/rdg"
        android:layout_width="match_parent"
        android:layout_height="30dp"
        android:layout_marginTop="888dp"
        android:gravity="center"
        android:orientation="horizontal"
        >
    </RadioGroup>

    <Button
        android:id="@+id/but"
        android:layout_width="188dp"
        android:layout_height="66dp"
        android:layout_alignParentBottom="true"
        android:gravity="center"
        android:layout_marginLeft="215dp"
        android:textSize="40sp"
        android:background="#00dddddd"
        android:layout_marginBottom="200dp"
        android:text="立即进入"
        android:textColor="#0f0"
        />

</RelativeLayout>

主题代码

public class MainActivity extends AppCompatActivity {

    private ViewPager vpr;
    private Button but;
    private RadioGroup rdg;
    private ArrayList<ImageView> list;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //获取控件
        vpr = findViewById(R.id.vpr);
        but = findViewById(R.id.but);
        rdg = findViewById(R.id.rdg);
        //隐藏
        but.setVisibility(View.GONE);
        //跳转
        but.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(MainActivity.this,Main2Activity.class);
                startActivity(intent);
                finish();
            }
        });
        //创建数组
        int arr[] = {R.drawable.a,R.drawable.b,R.drawable.c,R.drawable.d};
        //定义集合
        list = new ArrayList<ImageView>();
        //循环
        for (int i = 0;i<arr.length;i++){
            ImageView imageView = new ImageView(MainActivity.this);
            imageView.setImageResource(arr[i]);
            list.add(imageView);
            //创建小圆点
            RadioButton radioButton = new RadioButton(MainActivity.this);
            //加入小圆点
            rdg.addView(radioButton);
        }
        //选中第一个
        rdg.check(rdg.getChildAt(0).getId());
        //适配器
        vpr.setAdapter(new PagerAdapter() {
            @Override
            public int getCount() {
                return list.size();
            }

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

            @NonNull
            @Override
            public Object instantiateItem(@NonNull ViewGroup container, int position) {
                ImageView imageView = list.get(position);
                container.addView(imageView);
                return imageView;
            }

            @Override
            public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
                container.removeView((View) object);
            }
        });
        //联动
        vpr.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int i, float v, int i1) {

            }

            @Override
            public void onPageSelected(int i) {
                //判断隐藏
                if (i==list.size()-1){
                    but.setVisibility(View.VISIBLE);
                }else{
                    but.setVisibility(View.GONE);
                }
                rdg.check(rdg.getChildAt(i).getId());
            }

            @Override
            public void onPageScrollStateChanged(int i) {

            }
        });


    }
}