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

为视图添加边距。这对我很管用。

android:layout_marginTop="10dp"

如果你只是想在XML中添加相等的间距,只需在RecyclerView中设置padding,并在你膨胀到RecyclerView中的项目中设置等量的layoutMargin,并让背景颜色决定间距颜色。

其他回答

实现它自己的RecyclerView版本。ItemDecoration

public class SpacingItemDecoration extends RecyclerView.ItemDecoration {
    private int spacingPx;
    private boolean addStartSpacing;
    private boolean addEndSpacing;

    public SpacingItemDecoration(int spacingPx) {
        this(spacingPx, false, false);
    }

    public SpacingItemDecoration(int spacingPx, boolean addStartSpacing, boolean addEndSpacing) {
        this.spacingPx = spacingPx;
        this.addStartSpacing = addStartSpacing;
        this.addEndSpacing = addEndSpacing;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        if (spacingPx <= 0) {
            return;
        }

        if (addStartSpacing && parent.getChildLayoutPosition(view) < 1 || parent.getChildLayoutPosition(view) >= 1) {
            if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
                outRect.top = spacingPx;
            } else {
                outRect.left = spacingPx;
            }
        }

        if (addEndSpacing && parent.getChildAdapterPosition(view) == getTotalItemCount(parent) - 1) {
            if (getOrientation(parent) == LinearLayoutManager.VERTICAL) {
                outRect.bottom = spacingPx;
            } else {
                outRect.right = spacingPx;
            }
        }
    }

    private int getTotalItemCount(RecyclerView parent) {
        return parent.getAdapter().getItemCount();
    }

    private int getOrientation(RecyclerView parent) {
        if (parent.getLayoutManager() instanceof LinearLayoutManager) {
            return ((LinearLayoutManager) parent.getLayoutManager()).getOrientation();
        } else {
            throw new IllegalStateException("SpacingItemDecoration can only be used with a LinearLayoutManager.");
        }
    }
}

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;
        }
    }
}

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"/>

我觉得需要一个简单的、不使用XML的、基于代码的答案

DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(recyclerView.getContext(), DividerItemDecoration.VERTICAL);

ShapeDrawable shapeDrawableForDivider = new ShapeDrawable(new RectShape());

int dividerThickness = // (int) (SomeOtherView.getHeight() * desiredPercent);
shapeDrawableForDivider.setIntrinsicHeight(dividerThickness);
shapeDrawableForDivider.setAlpha(0);

dividerItemDecoration.setDrawable(shapeDrawableForDivider);

recyclerView.addItemDecoration(dividerItemDecoration);

我非常喜欢这个答案,我用Kotlin的单一表达式重新写了一遍:

    recyclerView.addItemDecoration(DividerItemDecoration(this,DividerItemDecoration.VERTICAL).also { deco ->
        with (ShapeDrawable(RectShape())){
            intrinsicHeight = (resources.displayMetrics.density * 24).toInt()
            alpha = 0
            deco.setDrawable(this)
        }
    })

这和@Nerdy最初的答案是一样的,只是它将分隔线的高度设置为24dp,而不是另一个视图高度的百分比。

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。:)