View事件分发原理和ViewPager+ListView嵌套滑动冲突

btn.setOnClickListener(new View.OnClickListener() {
  @Override
  public void onClick(View v) {
    Log.e("hover","onCLick");
  }
});
btn.setOnTouchListener(new View.OnTouchListener() {
  @Override
  public boolean onTouch(View v, MotionEvent event) {
    Log.e("hover", "onTouch:"   event.getAction());
    //return false;//return false的话两个打印日志都有
    return true;//只有onTouch日志会打印
  }
});

dispatchTransformedTouchEvent(ev, false, child, idBitsToAssign)
handled = child.dispatchTouchEvent(event);    

public class SlideInflictFragment extends Fragment {
  private BasePager mPager;
  List<MyListView> mListViews = new ArrayList<>();
  private String[] data={"Apple","Banana","Orange","Watermelon","Pear","Grape","Pineapple",
      "Strawberry","Cherry","Mango","Apple","Banana","Orange","Watermelon","Pear","Grape",
      "Pineapple","Strawberry","Cherry","Mango"};
  @Nullable
  @Override
  public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    return inflater.inflate(R.layout.slide_inflict_view_layout, container, false);
  }
  @Override
  public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

  }
  @Override
  public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
    super.onViewCreated(view, savedInstanceState);
    mPager = view.findViewById(R.id.viewPager);
    initListViews();
    mPager.setAdapter(new MyPagerAdapter(mListViews));
  }
  private void initListViews(){
    MyListView l1 = new MyListView(getContext());
    MyListView l2 = new MyListView(getContext());
    MyListView l3 = new MyListView(getContext());
    ArrayAdapter<String> adapter = new ArrayAdapter<>(getActivity(),R.layout.slide_inflict_list_item,data);
    l1.setAdapter(adapter);l2.setAdapter(adapter);l3.setAdapter(adapter);
    mListViews.add(l1);mListViews.add(l2);mListViews.add(l3);
  }
  public class MyPagerAdapter extends PagerAdapter{
    public List<MyListView> mListViews;
    public MyPagerAdapter(List<MyListView> mListViews) {
      this.mListViews = mListViews;
    }
    @Override
    public int getCount() {
      return mListViews.size();
    }

    @Override
    public boolean isViewFromObject(@NonNull View view, @NonNull Object object) {
      return view == object;
    }
    @NonNull
    @Override
    public Object instantiateItem(@NonNull ViewGroup container, int position) {
      container.addView(mListViews.get(position));
      return mListViews.get(position);
    }
    @Override
    public void destroyItem(@NonNull ViewGroup container, int position, @NonNull Object object) {
      container.removeView(mListViews.get(position));
    }
  }
}

public class MyListView extends ListView {
  public MyListView(Context context) {
    super(context);
  }
  public MyListView(Context context, AttributeSet attrs) {
    super(context, attrs);
  }
  public MyListView(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
  }
  private int mLastX,mLastY;
  @Override
  public boolean dispatchTouchEvent(MotionEvent event) {
    int x = (int) event.getX();
    int y = (int) event.getY();
    switch (event.getAction()){
      case MotionEvent.ACTION_DOWN:
        getParent().requestDisallowInterceptTouchEvent(true);//表示父容器不能拦截此事件
        break;
      case MotionEvent.ACTION_MOVE:
        int deltaX = x-mLastX;
        int deltaY = x-mLastY;
        if(Math.abs(deltaX)>Math.abs(deltaY)){
          getParent().requestDisallowInterceptTouchEvent(false);//表示可以拦截
        }
        break;
      default:
        break;
    }
    mLastX = x;
    mLastY = y;
    return super.dispatchTouchEvent(event);

  }
}

public class MyPager extends ViewPager {
  public MyPager(@NonNull Context context) {
    super(context);
  }
  public MyPager(@NonNull Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
  }
  @Override
  public boolean onInterceptTouchEvent(MotionEvent ev) {
    if (ev.getAction() == MotionEvent.ACTION_DOWN) {
      super.onInterceptTouchEvent(ev);
      return false;//必须要在down事件return false，否则listView就接收不到down事件，也就无法处理touchevent
    }
    return true;
  }
}