Android BottomSheetDialogFragment 状态变化监听器

Question

我正在使用

BottomSheetDialogFragment

，我需要知道状态何时发生变化。

例如有

BottomSheetBehavior

的状态

PEEK_HEIGHT_AUTO - Peek at the 16:9 ratio keyline of its parent.    
STATE_COLLAPSED - The bottom sheet is collapsed.
STATE_DRAGGING - The bottom sheet is dragging.
STATE_EXPANDED - The bottom sheet is expanded.
STATE_HIDDEN - The bottom sheet is hidden.
STATE_SETTLING - The bottom sheet is settling.

我想根据当前状态更改一些视图 - 例如，当

BottomSheetDialogFragment

将展开全屏时，我想在右上角显示十字图标以关闭它等..

我如何才能收听此类事件？

Answer 1

晚了，但可能是您问题的答案。你必须使用bottomSheetBehavior回调。

bottomSheetBehavior.setBottomSheetCallback(new BottomSheetBehavior.BottomSheetCallback() {
        @Override
        public void onStateChanged(View bottomSheet, int newState) {
  switch (newState) {
                case BottomSheetBehavior.STATE_COLLAPSED:
                    Log.d("Bottom Sheet Behavior", "STATE_COLLAPSED");
                    break;
                case BottomSheetBehavior.STATE_DRAGGING:
                    Log.d("Bottom Sheet Behavior", "STATE_DRAGGING");
                    break;
                case BottomSheetBehavior.STATE_EXPANDED:
                    Log.d("Bottom Sheet Behavior", "STATE_EXPANDED");

                    break;
                case BottomSheetBehavior.STATE_HIDDEN:
                    Log.d("Bottom Sheet Behavior", "STATE_HIDDEN");
                    bottomSheetBehavior.setState(BottomSheetBehavior.STATE_COLLAPSED);
                    break;
                case BottomSheetBehavior.STATE_SETTLING:
                    Log.d("Bottom Sheet Behavior", "STATE_SETTLING");
                    break;
            }
        }

Answer 2

要从

BottomSheetBehaviour

获取

BottomSheetDialogFragment

，您必须在

BottomSheetDialogFragment.from(yourView)

的

onCreateView

方法中使用

BottomSheetDialogFragment

。

结果（Kotlin）：

class MyFragment() : BottomSheetDialogFragment()
{
    override fun onCreateView(inflater: LayoutInflater,
                              container: ViewGroup?,
                              savedInstanceState: Bundle?): View?
    {
        var result = inflater.inflate(R.layout.fragment_bitmap, container, false)
        BottomSheetBehavior.from(result)
            .addBottomSheetCallback(object : BottomSheetBehavior.BottomSheetCallback()
                                    {

                                        override fun onStateChanged(bottomSheet: View,
                                                                    newState: Int)
                                        {
                                            // Here
                                        }

                                        override fun onSlide(p0: View, p1: Float)
                                        {
                                            //
                                        }
                                    })
        return result
    }
}