而不是创建一个形状xml来改变分隔线的高度和颜色，你可以通过编程来创建它:

val divider = DividerItemDecoration(
                  context,
                  DividerItemDecoration.VERTICAL)

divider.setDrawable(ShapeDrawable().apply {
    intrinsicHeight = resources.getDimensionPixelOffset(R.dimen.dp_15)
    paint.color = Color.RED // Note:
                            //   Currently (support version 28.0.0), we
                            //   can not use tranparent color here. If
                            //   we use transparent, we still see a
                            //   small divider line. So if we want
                            //   to display transparent space, we
                            //   can set color = background color
                            //   or we can create a custom ItemDecoration
                            //   instead of DividerItemDecoration.
})

recycler_devices.addItemDecoration(divider)

这实际上并不能解决问题，但是作为一种临时的解决方法，您可以在XML布局中的卡片上设置useCompatPadding属性，使其与在前lollipop版本中测量的相同。

card_view:cardUseCompatPadding="true"

对于GridLayoutManager，我使用这个:

public class GridSpacesItemDecoration : RecyclerView.ItemDecoration
{
    private int space;

    public GridSpacesItemDecoration(int space) {
        this.space = space;
    }

    public override void GetItemOffsets(Android.Graphics.Rect outRect, View view, RecyclerView parent, RecyclerView.State state)
    {
        var position = parent.GetChildLayoutPosition(view);

        /// Only for GridLayoutManager Layouts
        var manager = parent.GetLayoutManager() as GridLayoutManager;

        if (parent.GetChildLayoutPosition(view) < manager.SpanCount)
            outRect.Top = space;

        if (position % 2 != 0) {
            outRect.Right = space;
        }

        outRect.Left = space;
        outRect.Bottom = space;
    }
}

这适用于任何跨度。

如果有人想为spaceBetween, paddingLeft, paddingTop, paddingRight和paddingBottom设置不同的值。

class ItemPaddingDecoration(
    private val spaceBetween: Int,
    private val paddingLeft: Int = spaceBetween,
    private val paddingTop: Int = spaceBetween,
    private val paddingRight: Int = spaceBetween,
    private val paddingBottom: Int = spaceBetween
) : RecyclerView.ItemDecoration() {

    override fun getItemOffsets(outRect: Rect, view: View, parent: RecyclerView, state: RecyclerView.State) {
        val position = parent.getChildAdapterPosition(view)
        val orientation = when (val layoutManager = parent.layoutManager) {
            is LinearLayoutManager -> {
                layoutManager.orientation
            }
            is GridLayoutManager -> {
                layoutManager.orientation
            }
            else -> {
                RecyclerView.HORIZONTAL
            }
        }
        if (orientation == RecyclerView.HORIZONTAL) {
            when {
                position == 0 -> {
                    outRect.set(paddingLeft, paddingTop, spaceBetween, paddingBottom)
                }
                position < parent.adapter!!.itemCount - 1 -> {
                    outRect.set(0, paddingTop, spaceBetween, paddingBottom)
                }
                else -> {
                    outRect.set(0, paddingTop, paddingRight, paddingBottom)
                }
            }
        } else {
            when {
                position == 0 -> {
                    outRect.set(paddingLeft, paddingTop, paddingRight, paddingBottom)
                }
                position < parent.adapter!!.itemCount - 1 -> {
                    outRect.set(paddingLeft, 0, paddingRight, spaceBetween)
                }
                else -> {
                    outRect.set(paddingLeft, 0, paddingRight, paddingBottom)
                }
            }
        }
    }
}

简单的方法是为RecyclerView设置背景色，为项目设置不同的背景色。这里有一个例子……

<android.support.v7.widget.RecyclerView
    android:background="#ECEFF1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:scrollbars="vertical"/>

和TextView项目(它可以是任何东西)与底线“x”dp或px。

<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_marginBottom="1dp"
    android:background="#FFFFFF"/>

输出……

如果有人只想在项目之间添加10dp的间距，你可以通过设置一个drawable到DividerItemDecoration来实现:

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(
    recyclerView.getContext(),
    layoutManager.getOrientation()
);

dividerItemDecoration.setDrawable(
    ContextCompat.getDrawable(getContext(), R.drawable.divider_10dp)
);

recyclerView.addItemDecoration(dividerItemDecoration);

其中，divider_10dpis一个可绘制资源，包含:

<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle">
    <size android:height="10dp"/>
    <solid android:color="@android:color/transparent"/>
</shape>