view的事件分发可参考：事件分发
实现效果
吸顶、嵌套滑动的解决
上下滑动：当滑动下方的recyclerView的时候，先和上方的imageView一起滑动，等imageView完全滑动完再滑动recyclerView
左右滑动：实现tab的切换
吸顶：当imageView的滑动完后，tabLayout的一栏，紧贴最上方
部分代码逻辑
activity_main.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayoutxmlns:android="/apk/res/android"xmlns:app="/apk/res-auto"xmlns:tools="/tools"android:layout_width="match_parent"android:layout_height="match_parent"tools:context=".MainActivity"android:orientation="vertical"><com.example.testone.mynestedscroll.MyNestedScrollLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><LinearLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"><ImageViewandroid:layout_gravity="center"android:layout_width="match_parent"android:layout_height="300dp"android:scaleType="fitXY"android:src="@drawable/panda1"/><LinearLayoutandroid:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="vertical"><com.google.android.material.tabs.TabLayoutandroid:id="@+id/tab_layout"android:layout_width="match_parent"android:layout_height="wrap_content"android:background="#F3F3FA"/><androidx.viewpager2.widget.ViewPager2android:id="@+id/view_pager"android:layout_width="match_parent"android:layout_height="match_parent"/></LinearLayout></LinearLayout></com.example.testone.mynestedscroll.MyNestedScrollLayout></LinearLayout>
fragment_tab.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayoutxmlns:android="/apk/res/android"xmlns:app="/apk/res-auto"xmlns:tools="/tools"android:layout_width="wrap_content"android:layout_height="wrap_content"android:background="#1AFD9C"tools:context=".MainActivity"><androidx.recyclerview.widget.RecyclerViewandroid:id="@+id/recycler_view_1"android:layout_width="match_parent"android:layout_height="wrap_content"/></LinearLayout>
item_recycler_view.xml
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="/apk/res/android"android:layout_width="match_parent"android:layout_height="wrap_content"android:orientation="vertical"><TextViewandroid:id="@+id/recycler_test_text_tv"android:layout_width="match_parent"android:layout_height="50dp"android:background="#ccc"android:text="hello"android:textSize="100px"android:gravity="center"/><TextViewandroid:layout_width="match_parent"android:layout_height="1dp"android:background="#fff"/></LinearLayout>
MyPageAdapter
public class MyPageAdapter extends FragmentStateAdapter {private List<Fragment> data;public MyPageAdapter(@NonNull FragmentActivity fragmentActivity, List<Fragment> data) {super(fragmentActivity);this.data = data;}@NonNull@Overridepublic Fragment createFragment(int position) {return data.get(position);}@Overridepublic int getItemCount() {return data.size();}}
MyRecyclerViewAdapter
public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.MyViewHolder> {Context context;List<String> strList;public MyRecyclerViewAdapter(Context context, List<String> strList){this.context = context;this.strList = strList;}@NonNull@Overridepublic MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {View view = LayoutInflater.from(context).inflate(R.layout.item_recycler_view, parent, false);return new MyViewHolder(view);}@Overridepublic void onBindViewHolder(@NonNull MyViewHolder holder, final int position) {holder.textView.setText(strList.get(position));holder.textView.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {Toast.makeText(context, "点击了"+strList.get(position), Toast.LENGTH_SHORT).show();}});}@Overridepublic int getItemCount() {return strList.size();}public class MyViewHolder extends RecyclerView.ViewHolder {TextView textView;public MyViewHolder(@NonNull View itemView) {super(itemView);textView = itemView.findViewById(R.id.recycler_test_text_tv);}}}
MyNestedScrollLayout
public class MyNestedScrollLayout extends NestedScrollView {private static final String TAG = "MyNestedScrollLayout";private ViewGroup contentView;private View topView;public MyNestedScrollLayout(@NonNull Context context) {super(context);}public MyNestedScrollLayout(@NonNull Context context, @Nullable AttributeSet attrs) {super(context, attrs);}public MyNestedScrollLayout(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {super(context, attrs, defStyleAttr);}@Overrideprotected void onFinishInflate() {super.onFinishInflate();// 获取第一个孩子的第一个孩子topView = ((ViewGroup) getChildAt(0)).getChildAt(0);// 获取第一个孩子的第二个孩子contentView = (ViewGroup)((ViewGroup)getChildAt(0)).getChildAt(1);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {// 调整contentView的高度为父容器高度，使之填充布局，避免父容器滚动后出现空白super.onMeasure(widthMeasureSpec, heightMeasureSpec);ViewGroup.LayoutParams lp = contentView.getLayoutParams();lp.height = getMeasuredHeight();contentView.setLayoutParams(lp);}// 让父亲先滑动，至父亲完全滑动不可见，自己再滑动@Overridepublic void onNestedPreScroll(@NonNull View target, int dx, int dy, @NonNull int[] consumed, int type) {boolean hideTop = dy > 0 && getScrollY() < topView.getMeasuredHeight();if (hideTop) {scrollBy(0, dy);consumed[1] = dy; // 消费了多少，如果没有，就会重复滑动}}}
TabFragment
public class TabFragment extends Fragment {@Nullable@Overridepublic View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {View view = inflater.inflate(R.layout.fragment_tab, container, false);RecyclerView recyclerView;MyRecyclerViewAdapter myRecyclerViewAdapter;List<String> strList = new ArrayList<>();for (int i=0; i<30; i++){strList.add(""+i);}myRecyclerViewAdapter = new MyRecyclerViewAdapter(view.getContext(), strList);recyclerView = view.findViewById(R.id.recycler_view_1);recyclerView.setLayoutManager(new LinearLayoutManager(view.getContext()));recyclerView.setAdapter(myRecyclerViewAdapter);return view;}}
MainActivity
public class MainActivity extends AppCompatActivity {ArrayList<Fragment> fragmentList = new ArrayList<>();ViewPager2 viewPager;MyPageAdapter myPageAdapter;TabLayout tab_layout;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);TabFragment tabFragment1 = new TabFragment();TabFragment tabFragment2 = new TabFragment();TabFragment tabFragment3 = new TabFragment();fragmentList.add(tabFragment1);fragmentList.add(tabFragment2);fragmentList.add(tabFragment3);viewPager = findViewById(R.id.view_pager);myPageAdapter = new MyPageAdapter(this, fragmentList);viewPager.setAdapter(myPageAdapter);tab_layout = findViewById(R.id.tab_layout);new TabLayoutMediator(tab_layout, viewPager, new TabLayoutMediator.TabConfigurationStrategy() {@Overridepublic void onConfigureTab(@NonNull TabLayout.Tab tab, int position) {tab.setText("TAB-"+position);}}).attach();}}
演示源码地址：
完整演示代码：TabLayout-ViewPager2
持续努力，不断输出中…
