Question

我已在recyclerView项上设置了滑动手势以进行编辑。我已经做到了：

private val swipeHelper = object : ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT or ItemTouchHelper.RIGHT) {

    override fun onMove(recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder, target: RecyclerView.ViewHolder): Boolean {
            return false
        }

        override fun onSwiped(viewHolder: RecyclerView.ViewHolder, direction: Int) {
            val position = viewHolder.adapterPosition //get position which is swipe

            if (direction == ItemTouchHelper.RIGHT) {
                … // do stuff
            }
        }

    override fun onChildDraw(c: Canvas, recyclerView: RecyclerView, viewHolder: RecyclerView.ViewHolder, dX: Float, dY: Float, actionState: Int, isCurrentlyActive: Boolean) {
            val icon: Bitmap

            if (actionState == ItemTouchHelper.ACTION_STATE_SWIPE) {
                val itemView = viewHolder.itemView
                val height: Float = (itemView.bottom.toFloat() - itemView.top.toFloat())
                val width = height / 3

                if (dX > 0) {
                    paint.color = Color.parseColor("#FF9300")
                    val background = RectF(itemView.left.toFloat(), itemView.top.toFloat(), dX, itemView.bottom.toFloat())
                    c.drawRect(background, paint)
                    icon = BitmapFactory.decodeResource(resources, R.drawable.pencil)
                    val iconDest = RectF(
                            itemView.left.toFloat() + width,
                            itemView.top.toFloat() + width,
                            itemView.left.toFloat() + 2*width,
                            itemView.bottom.toFloat() - width)
                    c.drawBitmap(icon, null, iconDest, paint)
                }
            }
            super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)
        }

}

我面临的问题是，我无法弄清楚如何解决的问题是，在滑动之后，由于我没有删除元素，因此在完全重新启动活动之前，不会重置动画。

以下是说明图：

有人处理过这个问题吗？关于如何解决它而不必重新启动整个活动的任何想法？

Answer 1

在适配器上呼叫notifyItemChanged。这将重置适配器。

Answer 2

您可以在活动中通过调用notifyDatasetChanged();或notifyItemChanged();来做到这一点：

    ItemTouchHelper.SimpleCallback callback = new RecyclerItemTouchHelper(this, 0, ItemTouchHelper.LEFT
            , new RecyclerItemTouchHelper.RecyclerItemTouchHelperListener() {
            @Override
            public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction, final int position) {
            if (direction == ItemTouchHelper.LEFT) {
                // do what you want here and after that call the function below:
                recyclerAdapter.notifyItemChanged(position);
            }
        }
    });
    new ItemTouchHelper(callback).attachToRecyclerView(recyclerView);

Android-RecyclerView滑动动画不会消失

2 个答案: