这是之前在ListView类中使用divider和dividerHeight参数实现的一个例子:

<ListView
    android:id="@+id/activity_home_list_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:divider="@android:color/transparent"
    android:dividerHeight="8dp"/>

然而,在RecyclerView类中我没有看到这样的可能性。

<android.support.v7.widget.RecyclerView
    android:id="@+id/activity_home_recycler_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:scrollbars="vertical"/>

在这种情况下,是否可以定义边距和/或直接添加自定义分隔符视图到列表项的布局中,或者是否有更好的方法来实现我的目标?


当前回答

您可以通过编程方式轻松地添加它。

如果你的布局管理器是线性布局,那么你可以使用:

DividerItemDecoration是一个RecyclerView。ItemDecoration即可以 用作LinearLayoutManager项之间的分隔符。它支持 水平方向和垂直方向。

mDividerItemDecoration =
  new DividerItemDecoration(recyclerView.getContext(),
                            mLayoutManager.getOrientation());
recyclerView.addItemDecoration(mDividerItemDecoration);

其他回答

其中一种方法是同时使用cardview和recycler视图。我们可以很容易地添加一个效果,比如分隔线。 示例:使用RecyclerView创建动态列表 另一种方法是将视图作为分隔符添加到回收器视图的list_item_layout中。 <视图 android: id =“@ + id / view1” android: layout_width = " match_parent " android: layout_height = " 1 dp " android:背景= " @color / colorAccent " / >

public class CommonItemSpaceDecoration extends RecyclerView.ItemDecoration {

    private int mSpace = 0;
    private boolean mVerticalOrientation = true;

    public CommonItemSpaceDecoration(int space) {
        this.mSpace = space;
    }

    public CommonItemSpaceDecoration(int space, boolean verticalOrientation) {
        this.mSpace = space;
        this.mVerticalOrientation = verticalOrientation;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.top = SizeUtils.dp2px(view.getContext(), mSpace);
        if (mVerticalOrientation) {
            if (parent.getChildAdapterPosition(view) == 0) {
                outRect.set(0, SizeUtils.dp2px(view.getContext(), mSpace), 0, SizeUtils.dp2px(view.getContext(), mSpace));
            } else {
                outRect.set(0, 0, 0, SizeUtils.dp2px(view.getContext(), mSpace));
            }
        } else {
            if (parent.getChildAdapterPosition(view) == 0) {
                outRect.set(SizeUtils.dp2px(view.getContext(), mSpace), 0, 0, 0);
            } else {
                outRect.set(SizeUtils.dp2px(view.getContext(), mSpace), 0, SizeUtils.dp2px(view.getContext(), mSpace), 0);
            }
        }
    }
}

这将增加每个项目的顶部和底部(或左右)的空间。然后你可以将它设置为你的recyclerView。

recyclerView.addItemDecoration(new CommonItemSpaceDecoration(16));

文件SizeUtils.java

public class SizeUtils {
    public static int dp2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return (int) (dpValue * scale + 0.5f);
    }
}

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"

为了在RecylerView中实现项目之间的间隔,我们可以使用ItemDecorators:

addItemDecoration(object : RecyclerView.ItemDecoration() {

    override fun getItemOffsets(
        outRect: Rect,
        view: View,
        parent: RecyclerView,
        state: RecyclerView.State,
    ) {
        super.getItemOffsets(outRect, view, parent, state)
        if (parent.getChildAdapterPosition(view) > 0) {
            outRect.top = 8.dp // Change this value with anything you want. Remember that you need to convert integers to pixels if you are working with dps :)
        }
    }
})

对于我粘贴的代码,有几件事需要考虑:

You don't really need to call super.getItemOffsets but I chose to, because I want to extend the behavior defined by the base class. If the library got an update doing more logic behind the scenes, we would miss it. As an alternative to adding top spacing to the Rect, you could also add bottom spacing, but the logic related to getting the last item of the adapter is more complex, so this might be slightly better. I used an extension property to convert a simple integer to dps: 8.dp. Something like this might work:

val Int.dp: Int
    get() = (this * Resources.getSystem().displayMetrics.density + 0.5f).toInt()

// Extension function works too, but invoking it would become something like 8.dp()

请注意一下Alex Fu在GitHub上的这个文件: 链接

它是“直接从支持演示中提取”的diveritemdecoration .java示例文件。

在我的项目中导入这个文件后,我能够很好地获得分隔线,并将其作为项目装饰添加到回收器视图。

下面是我的onCreateView在我的片段中包含Recyclerview的样子:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_recycler_view, container, false);

    mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
    mRecyclerView.addItemDecoration(new DividerItemDecoration(getActivity(), DividerItemDecoration.VERTICAL));

    mRecyclerView.setHasFixedSize(true);
    mLayoutManager = new LinearLayoutManager(getActivity());
    mRecyclerView.setLayoutManager(mLayoutManager);
    mRecyclerView.setItemAnimator(new DefaultItemAnimator());

    return rootView;
}

我确信可以做额外的造型,但这只是一个起点。:)