android - 如何将左侧和右侧的 ItemDecoration 都应用于 RecyclerView 项目？

Question

长期以来，我一直在努力实现这一目标。我想要的是将选定的 RecyclerView 项从左到右重叠，如下图所示。

我可以通过 ItemDecoration 实现向左或向右的效果，如下所示:

class OverlapDecoration(private val overlapWidth:Int) : RecyclerView.ItemDecoration() {
    private val overLapValue = -40

    val TAG = OverlapDecoration::class.java.simpleName

    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State?) {

        val itemPosition = parent.getChildAdapterPosition(view)

        if (itemPosition == 0) {
            return
        } else {
            outRect.set(overLapValue, 0, 0, 0)
        }
    }
}

到目前为止，我已经实现了如下图所示。

我已经尝试过 CarouselLayoutManager但这不是我要找的。

Answer 1

要获得您正在寻找的结果，您需要采取两个步骤:

首先，修正装饰器的计算:

if (itemPosition == 0) {
    return
} else {
    outRect.set(-1 * overLapValue, 0, overLapValue, 0) //Need left, AND right
}

其次，你需要实际添加阴影

并且，对类进行快速清理，您不需要 private val overLapValue。

改为:

class OverlapDecoration(private val overlapWidth:Int = 40) : RecyclerView.ItemDecoration() {