使用这个类在你的RecyclerView中设置分隔符。

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {

    private int spanCount;
    private int spacing;
    private boolean includeEdge;

    public GridSpacingItemDecoration(int spanCount, int spacing, boolean includeEdge) {
        this.spanCount = spanCount;
        this.spacing = spacing;
        this.includeEdge = includeEdge;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        int position = parent.getChildAdapterPosition(view); // Item position
        int column = position % spanCount; // Item column

        if (includeEdge) {
            outRect.left = spacing - column * spacing / spanCount; // spacing - column * ((1f / spanCount) * spacing)
            outRect.right = (column + 1) * spacing / spanCount; // (column + 1) * ((1f / spanCount) * spacing)

            if (position < spanCount) { // Top edge
                outRect.top = spacing;
            }
            outRect.bottom = spacing; // Item bottom
        } else {
            outRect.left = column * spacing / spanCount; // column * ((1f / spanCount) * spacing)
            outRect.right = spacing - (column + 1) * spacing / spanCount; // spacing - (column + 1) * ((1f / spanCount) * spacing)
            if (position >= spanCount) {
                outRect.top = spacing; // Item top
            }
        }
    }
}

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……

我们可以使用附加到recyclerview的各种装饰器来装饰物品，例如:

简单地使用下面的…从答案中提取

public class DividerItemDecoration extends RecyclerView.ItemDecoration {

    private static final int[] ATTRS = new int[]{android.R.attr.listDivider};

    private Drawable mDivider;

    /**
     * Default divider will be used
     */
    public DividerItemDecoration(Context context) {
        final TypedArray styledAttributes = context.obtainStyledAttributes(ATTRS);
        mDivider = styledAttributes.getDrawable(0);
        styledAttributes.recycle();
    }

    /**
     * Custom divider will be used
     */
    public DividerItemDecoration(Context context, int resId) {
        mDivider = ContextCompat.getDrawable(context, resId);
    }

    @Override
    public void onDraw(Canvas c, RecyclerView parent, RecyclerView.State state) {
        int left = parent.getPaddingLeft();
        int right = parent.getWidth() - parent.getPaddingRight();

        int childCount = parent.getChildCount();
        for (int i = 0; i < childCount; i++) {
            View child = parent.getChildAt(i);

            RecyclerView.LayoutParams params = (RecyclerView.LayoutParams) child.getLayoutParams();

            int top = child.getBottom() + params.bottomMargin;
            int bottom = top + mDivider.getIntrinsicHeight();

            mDivider.setBounds(left, top, right, bottom);
            mDivider.draw(c);
        }
    }
}

然后用上面的方法如下:

RecyclerView.ItemDecoration itemDecoration = new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST);
recyclerView.addItemDecoration(itemDecoration);

这将在列表中的每个项目之间显示分隔符，如下所示:

对于那些想要了解更多细节的人，可以看看这个指南Using the recyclerview_ CodePath Android Cliffnotes。

这里的一些答案建议使用边距，但问题是:

如果你同时添加了上边距和下边距，它们将在项目之间显示为添加的，而且它们将太大。如果只添加其中之一，则整个列表的顶部或底部都没有边距。如果你在上面加上一半的距离，在下面加上一半的距离，外层的边缘就太小了。

因此，唯一美观上正确的解决方案是系统知道在哪里正确应用的分隔符:项目之间，但不是项目的上面或下面。

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。

因为我已经设置了ItemAnimators。ItemDecorator不会随着动画一起进入或退出。

我只是在我的项目视图布局文件中为每个项目设置了一个视图行。它解决了我的案子。对于一个简单的分割器来说，我觉得它的魔法太多了。

<View
    android:layout_width="match_parent"
    android:layout_height="1px"
    android:layout_marginLeft="5dp"
    android:layout_marginRight="5dp"
    android:background="@color/lt_gray"/>

一个简单的ItemDecoration实现，所有项目之间的空间相等:

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {
    private int space;

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

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.left = space;
        outRect.right = space;
        outRect.bottom = space;

        // Add top margin only for the first item to avoid double space between items
        if(parent.getChildAdapterPosition(view) == 0) {
            outRect.top = space;
        }
    }
}