Bottomsheetdialogfragment conflicts with listview recyclerview Scrollview sliding

1. The phenomenon ：BottomSheetDialogFragment You can slide up and down through gestures , frequently-used ListView  RecyclerView ScrollView Can also slide up and down , There will be some conflict problems , such as ScrollView When you want to slide down ,ScrollView The content doesn't slide , however BottomSheetDialogFragment It was pulled down and closed .

2. Source code analysis

open BottomSheetDialog Source code ：

private View wrapInBottomSheet(int layoutResId, View view, ViewGroup.LayoutParams params) {
        final FrameLayout container = (FrameLayout) View.inflate(getContext(),
                R.layout.design_bottom_sheet_dialog, null);
        final CoordinatorLayout coordinator =
                (CoordinatorLayout) container.findViewById(R.id.coordinator);
        if (layoutResId != 0 && view == null) {
            view = getLayoutInflater().inflate(layoutResId, coordinator, false);
        }
        FrameLayout bottomSheet = (FrameLayout) coordinator.findViewById(R.id.design_bottom_sheet);
        mBehavior = BottomSheetBehavior.from(bottomSheet);
        mBehavior.setBottomSheetCallback(mBottomSheetCallback);
        mBehavior.setHideable(mCancelable);
        if (params == null) {
            bottomSheet.addView(view);
        } else {
            bottomSheet.addView(view, params);
        }
    	//... Omit 
        return container

Incoming View Will eventually be add Into one FrameLayout Of bottomSheet in , And then through bottomSheet To instantiate a BottomSheetBehavior, And then give this mBehavior Set up a mBottomSheetCallback, Let's see what it is ：

 private BottomSheetBehavior.BottomSheetCallback mBottomSheetCallback
            = new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View bottomSheet,
                @BottomSheetBehavior.State int newState) {
            if (newState == BottomSheetBehavior.STATE_HIDDEN) {
                cancel();
            }
        }
 
        @Override
        public void onSlide(@NonNull View bottomSheet, float slideOffset) {
        }
    };

3. Solution ：

3.1 Method 1： rewrite BottomSheetCallback The logic of judgment in

private BottomSheetBehavior.BottomSheetCallback mBottomSheetCallback
            = new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View bottomSheet,
                                   @BottomSheetBehavior.State int newState) {
            if (newState == BottomSheetBehavior.STATE_DRAGGING) {// When judged as drag down behavior , Then the forced setting status is expanded 
                bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED );
            }
            LogUtil.e(TAG, "onStateChanged——>" + newState);
        }
 
        @Override
        public void onSlide(@NonNull View bottomSheet, float slideOffset) {
            LogUtil.e(TAG, "onSlide——>" + slideOffset);
        }
    };

3.2 Method 2 ： Direct, simple and rough ：

Just in RecyclerView ListView A layer of outer covering NestedScrollViewl, If it was ScrollView Replace with NestedScrollViewl