[移动开发]仿IOS滑动屏幕关闭界面实现

1、我们创建一个activity，然后添加ViewPager2的布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/vp_main"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</LinearLayout>

将需要展示的界面都添加到CopyOnWriteArrayList中并创建对应的Adapter,如下:

public class PageAdapter extends FragmentStateAdapter {
    private CopyOnWriteArrayList<Fragment> fragments;

    public PageAdapter(@NonNull FragmentActivity fragmentActivity, CopyOnWriteArrayList<Fragment> fragments) {
        super(fragmentActivity);
        this.fragments = fragments;
    }

    public PageAdapter(@NonNull FragmentActivity fragmentActivity) {
        super(fragmentActivity);
    }

    @NonNull
    @Override
    public Fragment createFragment(int position) {
        return fragments.get(position);
    }

    @Override
    public int getItemCount() {
        return fragments.size();
    }

}


CopyOnWriteArrayList fragments = new CopyOnWriteArrayList<>();

fragments.add(fragment界面1)

fragments.add(fragment界面2)

fragments.add(fragment界面3)...

ViewPager2.setAdapter(PageAdapter);

viewPager2.setOffscreenPageLimit(3);//表示三个界面之间来回切换都不会重新加载

viewPager2.setCurrentItem(0)//设置当前界面

2、引入第三方库

implementation 'com.r0adkll:slidableactivity:2.0.5'

在对应界面添加如下代码即可实现

SlidrConfig config = new SlidrConfig.Builder()
        .position(SlidrPosition.TOP)
        .scrimStartAlpha(1f)
        .scrimEndAlpha(1f)
        .edge(false)
        .build();
Slidr.attach(this, config);