相关疑难解决方法(0)

我试图禁用用户拖动BottomSheet.我想禁用的原因是两件事.1.它阻止ListView向下滚动,2.我不希望用户使用拖动但是使用按钮来解除BottomSheetView.这就是我所做的

 bottomSheetBehavior = BottomSheetBehavior.from(bottomAnc);
    bottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(@NonNull View bottomSheet, int newState) {
            if (newState == BottomSheetBehavior.STATE_EXPANDED) {
                //Log.e("BottomSheet", "Expanded");
            } else if (newState == BottomSheetBehavior.STATE_COLLAPSED) {
                //Log.e("BottomSheet", "Collapsed");
            }
        }

        @Override
        public void onSlide(@NonNull View bottomSheet, float slideOffset) {
            // React to dragging events
            bottomSheet.setOnTouchListener(new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    int action = MotionEventCompat.getActionMasked(event);
                    switch (action) {
                        case MotionEvent.ACTION_DOWN:
                            return false;
                        default:
                            return true;
                    } …

LinearLayout bottomSheetViewgroup = (LinearLayout) findViewById(R.id.bottomSheet);

bottomSheetBehavior = BottomSheetBehavior.from(bottomSheetViewgroup);

bottomSheetBehavior.setState(BottomSheetBehavior.STATE_EXPANDED); //this line

我在我的activity的onCreate()方法中有这个代码,当执行最后一行时,我得到了下面的NPE异常:

引发者:java.lang.NullPointerException:尝试在android.support.design.widget.BottomSheetBehavior.setState上的空对象引用上调用虚方法'java.lang.Object java.lang.ref.WeakReference.get()'( BottomSheetBehavior.java:440)

如何禁用BottomSheetDialogFragment手指拖动？

我看到了类似的问题,但他们BottomSheet都不是BottomSheetDialogFragment.