2016 年 10 月更新
Android Support Library 25.0.0 版本引入了DividerItemDecoration该类：
DividerItemDecoration 是一个 RecyclerView.ItemDecoration ，可用作 a 的项目之间的分隔符LinearLayoutManager。它同时支持HORIZONTAL和VERTICAL方向。
用法：
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
layoutManager.getOrientation());
recyclerView.addItemDecoration(dividerItemDecoration);
上一个答案
有些答案要么使用已被弃用的方法，要么没有给出完整的解决方案，所以我尝试做一个简短的、最新的总结。
与 不同ListView的是，RecyclerView该类没有任何与分隔符相关的参数。相反，您需要扩展ItemDecorationaRecyclerView的内部类：
允许应用ItemDecoration程序从适配器的数据集中向特定项目视图添加特殊的绘图和布局偏移。这对于在项目、突出显示、视觉分组边界等之间绘制分隔线很有用。
所有ItemDecorations都按照添加的顺序绘制，在项目视图之前（在 中onDraw()）和在项目之后（在 onDrawOver( Canvas, RecyclerView, RecyclerView.State).
Vertical间距ItemDecoration
扩展ItemDecoration，添加一个以空格height为参数的自定义构造函数并覆盖该getItemOffsets()方法：
public class VerticalSpaceItemDecoration extends RecyclerView.ItemDecoration {
private final int verticalSpaceHeight;
public VerticalSpaceItemDecoration(int verticalSpaceHeight) {
this.verticalSpaceHeight = verticalSpaceHeight;
}
@Override
public void getItemOffsets(Rect outRect, View view, RecyclerView parent,
RecyclerView.State state) {
outRect.bottom = verticalSpaceHeight;
}
}
如果您不想在最后一项下方插入空格，请添加以下条件：
if (parent.getChildAdapterPosition(view) != parent.getAdapter().getItemCount() - 1) {
outRect.bottom = verticalSpaceHeight;
}
注意：您还可以修改outRect.top,outRect.left和outRect.right属性以获得所需的效果。
分频器ItemDecoration
扩展ItemDecoration并覆盖该onDraw()方法：
public class DividerItemDecoration extends RecyclerView.ItemDecoration {
private static final int[] ATTRS = new int[]{android.R.attr.listDivider};
private Drawable divider;
/**
* Default divider will be used
*/
public DividerItemDecoration(Context context) {
final TypedArray styledAttributes = context.obtainStyledAttributes(ATTRS);
divider = styledAttributes.getDrawable(0);
styledAttributes.recycle();
}
/**
* Custom divider will be used
*/
public DividerItemDecoration(Context context, int resId) {
divider = 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 + divider.getIntrinsicHeight();
divider.setBounds(left, top, right, bottom);
divider.draw(c);
}
}
}
您可以调用第一个使用默认 Android 分隔符属性的构造函数，也可以调用第二个使用您自己的可绘制对象的构造函数，例如drawable/divider.xml：
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<size android:height="1dp" />
<solid android:color="#ff992900" />
</shape>
注意：如果您希望在您的项目上绘制分隔线，请改写该onDrawOver()方法。
用法
要使用您的新类，请添加VerticalSpaceItemDecoration或DividerSpaceItemDecoration，RecyclerView例如在您的片段onCreateView()方法中：
private static final int VERTICAL_ITEM_SPACE = 48;
private RecyclerView recyclerView;
private LinearLayoutManager linearLayoutManager;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_feed, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.fragment_home_recycler_view);
linearLayoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(linearLayoutManager);
//add ItemDecoration
recyclerView.addItemDecoration(new VerticalSpaceItemDecoration(VERTICAL_ITEM_SPACE));
//or
recyclerView.addItemDecoration(new DividerItemDecoration(getActivity()));
//or
recyclerView.addItemDecoration(
new DividerItemDecoration(getActivity(), R.drawable.divider));
recyclerView.setAdapter(...);
return rootView;
}
还有Lucas Rocha 的图书馆，旨在简化物品装饰过程。我还没有尝试过。
其特点包括：
- 库存物品装饰品的集合，包括：
- 项目间距水平/垂直分隔线。
- 项目清单
