使用带有StaggeredGridLayoutManager的RecyclerView时,如何避免项目之间的双重空间？

Question

我正在使用带有StaggeredGridLayoutManager的RecyclerView来创建一个两列列表.但是如何在左列和右列之间设置右边距.我已经使用此代码从顶部创建右边距,但如何解决列之间的双倍空格.

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 or second item to avoid double space between items
        // Add top margin only for the first or second item to avoid double space between items
        if((parent.getChildCount() > 0 && parent.getChildPosition(view) == 0)
            || (parent.getChildCount() > 1 && parent.getChildPosition(view) == 1))
        outRect.top = space;
}

在活动中:

recyclerView.addItemDecoration(new SpacesItemDecoration(20));

我试过用view.getX(),它总是返回0.

谁能帮我？非常感谢!

Answer 1

以下代码将处理StaggeredGridLayoutManager,GridLayoutManager和LinearLayoutManager.

public class SpacesItemDecoration extends RecyclerView.ItemDecoration {

    private int halfSpace;

    public SpacesItemDecoration(int space) {
        this.halfSpace = space / 2;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {

        if (parent.getPaddingLeft() != halfSpace) {
            parent.setPadding(halfSpace, halfSpace, halfSpace, halfSpace);
            parent.setClipToPadding(false);
        }

        outRect.top = halfSpace;
        outRect.bottom = halfSpace;
        outRect.left = halfSpace;
        outRect.right = halfSpace;
    }
}

Answer 2

在您的情况下,您可以将两个边距设置为RecyclerView.但在我的情况下,在RecyclerView中有一个与屏幕宽度匹配的图像,我使用ItemDecoration来解决问题.

  class ViewItemDecoration extends RecyclerView.ItemDecoration {

    public ViewItemDecoration() {
    }

    @Override
    public void getItemOffsets(Rect outRect, final View view, final RecyclerView parent, RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        int position = parent.getChildAdapterPosition(view);
        int spanIndex = ((StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams()).getSpanIndex();
        int type = adapter.getItemViewType(position);
        switch(type){
          case YOUR_ITEMS:
                if (spanIndex == 0) {
                    outRect.left = 10;
                    outRect.right = 5;
                } else {//if you just have 2 span . Or you can use (staggeredGridLayoutManager.getSpanCount()-1) as last span
                    outRect.left = 5;
                    outRect.right = 10;
                }
        }
    }

}

Answer 3

public class EqualGapItemDecoration extends RecyclerView.ItemDecoration {

    private int spanCount;
    private int spacing;

    public EqualGapItemDecoration(int spanCount, int spacing) {
        this.spanCount = spanCount;
        this.spacing = spacing;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {

        StaggeredGridLayoutManager.LayoutParams layoutParams = (StaggeredGridLayoutManager.LayoutParams) view.getLayoutParams();

        if (layoutParams.isFullSpan()) {
            outRect.set(0, 0, 0, 0);
        } else {
            int spanIndex = layoutParams.getSpanIndex();
            int layoutPosition = layoutParams.getViewLayoutPosition();
            int itemCount = parent.getAdapter().getItemCount();

            boolean leftEdge = spanIndex == 0;
            boolean rightEdge = spanIndex == (spanCount - 1);

            boolean topEdge = spanIndex < spanCount;
            boolean bottomEdge = layoutPosition >= (itemCount - spanCount);

            int halfSpacing = spacing / 2;

            outRect.set(
                    leftEdge ? spacing : halfSpacing,
                    topEdge ? spacing : halfSpacing,
                    rightEdge ? spacing : halfSpacing,
                    bottomEdge ? spacing : 0
            );
        }
    }
}

Answer 4

我自己通过设置项目边距和 RecyclerView 填充解决了这个问题。margin 和 padding 都是预期空间的一半，因此问题消失了。