引导页_简单版

1.切记写引导页不用导依赖
2.写布局

<?xml version="1.0" encoding="utf-8"?>
<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.support.v4.view.ViewPager
    android:id="@+id/pag"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    />
<Button
    android:id="@+id/button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:layout_marginBottom="73dp"
    android:layout_weight="1"
    android:text="进入" />
<RadioGroup
    android:id="@+id/rg"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:orientation="horizontal"
    android:layout_alignParentBottom="true"
    android:gravity="center"
    android:layout_alignParentLeft="true"
    android:layout_weight="2"/>

3.往相对应的MainActivity页面写代码

public class MainActivity extends AppCompatActivity {

private ViewPager pag;

private Button button;
private RadioGroup rg;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    pag = findViewById(R.id.pag);
    button = findViewById(R.id.button);
    //点击跳转
    button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent in=new Intent(MainActivity.this,Main2Activity.class);
            startActivity(in);
        }
    });
    rg = findViewById(R.id.rg);
    //数组放的图片
    int arr[]={R.drawable.a1,R.drawable.a11,R.drawable.a2};
    //自己定义的list集合  和for循环
    final List<ImageView> list=new ArrayList<ImageView>();
    for (int i=0;i<arr.length;i++){
  		//定义图片
        ImageView imag=new ImageView(MainActivity.this);
        imag.setImageResource(arr[i]);
        list.add(imag);
        //写小圆点
        RadioButton rb=new RadioButton(MainActivity.this);
        rg.addView(rb);
    }
    rg.check(rg.getChildAt(0).getId());
    //适配器
    pag.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) {
        //设置图片
            ImageView ima=list.get(position);
            //添加图片布局
            container.addView(ima);
            return ima;
        }
        @Override
        public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
        //删除布局
            container.removeView((View) object);
        }
    });

    pag.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
        @Override
        public void onPageScrolled(int i, float v, int i1) {
        //判断隐藏按钮
            if (i==list.size()-1) {
                button.setVisibility(View.VISIBLE);
            }
            else {
                button.setVisibility(View.GONE);
            }
        }

        @Override
        public void onPageSelected(int i) {
        //选中页面
            rg.check(rg.getChildAt(i).getId());
        }

        @Override
        public void onPageScrollStateChanged(int i) {

        }
    });

}
}