2016 年 10 月更新
Android 支持库 25.0.0 版本引入了DividerItemDecoration class:
DividerItemDecoration 是一个 RecyclerView.ItemDecoration,可以用作项目之间的分隔线LinearLayoutManager
。它同时支持HORIZONTAL
and VERTICAL
方向。
Usage:
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(),
layoutManager.getOrientation());
recyclerView.addItemDecoration(dividerItemDecoration);
之前的回答
有些答案要么使用已被弃用的方法,要么没有提供完整的解决方案,因此我尝试做一个简短的最新总结。
Unlike ListView
, the RecyclerView
类没有任何与分隔符相关的参数。相反,您需要扩展ItemDecoration, a RecyclerView
的内部类:
An ItemDecoration
允许应用程序将特殊的绘图和布局偏移添加到适配器数据集中的特定项目视图。这对于在项目、突出显示、视觉分组边界等之间绘制分隔线非常有用。
All ItemDecorations
按照添加顺序绘制,在项目视图之前(在onDraw()
)和项目之后(在 onDrawOver(Canvas
, RecyclerView
, RecyclerView.State)
.
Vertical
间距ItemDecoration
Extend ItemDecoration
,添加一个占用空间的自定义构造函数height
作为参数并覆盖getItemOffsets()
method:
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:还可以修改outRect.top
, outRect.left
and outRect.right
属性以获得所需的效果。
Divider ItemDecoration
Extend ItemDecoration
并覆盖onDraw()
method:
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);
}
}
}
例如,您可以调用使用默认 Android 分隔符属性的第一个构造函数,也可以调用使用您自己的可绘制对象的第二个构造函数可绘制/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:如果你想绘制分隔线over你的物品,覆盖onDrawOver()
方法代替。
Usage
要使用您的新课程,请添加VerticalSpaceItemDecoration
or DividerSpaceItemDecoration
to RecyclerView
,例如在您的片段中onCreateView()
method:
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;
}
还有卢卡斯·罗查的图书馆这应该是为了简化物品装饰过程。不过我还没试过。
其中,其features are:
- 库存装饰品的集合,包括:
- 项目间距水平/垂直分隔线。
- 项目清单