RecyclerView SimpleItemDivider之间不添加分隔符

Question

我试图在回收站视图中的每个列表项之间添加一些空格，但由于某些原因它没有相应的工作。我一直在遵循实施此解决方案的指南，但似乎无法找到答案。它正在添加空间，但空间放在下一个列表项上。

这就是我的recyclerview目前的样子： - My RecyclerView

这是我的类： - divider.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
    android:shape="rectangle">

    <size
        android:width="40dp"
        android:height="40dp" />

    <solid 
        android:color="@color/white"/>

</shape>

SimpleDividerItemDecoration类

public class SimpleDividerItemDecoration extends RecyclerView.ItemDecoration {

    private Drawable mDivider;

    public SimpleDividerItemDecoration(Context context) {
        mDivider = ContextCompat.getDrawable(context,R.drawable.divider);
    }

    @Override
    public void onDrawOver(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);
        }
    }
}

我的Fragment类中的onCreate方法，我得到了对象

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View v = inflater.inflate(R.layout.fragment_popular_picks, container, false);

        recyclerView = (RecyclerView)v.findViewById(R.id.popular_pick_recyclerView);
        recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        recyclerView.addItemDecoration(new SimpleDividerItemDecoration(getContext()));

        getPopularPost();

        return v;
    }

Answer 1

添加以下行代码，希望它能解决您的问题

recyclerView.addItemDecoration（new GridSpacingItemDecoration（2，dpToPx（10），true））;

这里是GridSpacingItemDecoration类

/ ** * RecyclerView项目装饰 - 在网格项目周围给出相等的边距* /

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
            }
        }
    }
}

/**
 * Converting dp to pixel
 */
private int dpToPx(int dp) {
    Resources r = getResources();
    return Math.round(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, r.getDisplayMetrics()));
}

Answer 2

如果您只需要添加空间，请考虑将其添加到项目布局（列表项的.xml文件）。这可以是RecyclerView中每个项目的一些填充。

如果你需要添加常规分频器，请考虑使用默认的DividerItemDecoration。它可以从appcompat库25.0.0获得。

您可以这样添加它：

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

Answer 3

为什么不在您创建的背景下在recyclerview项目的底部添加自定义视图？