使用网格布局显示额外间距的Recyclerview

<androidx.recyclerview.widget.RecyclerView
    android:id="@+id/recyclerView"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    />

RecyclerView recyclerView = findViewById(R.id.recyclerView);
recyclerView.setLayoutManager(new GridLayoutManager(this, 列数));

public class GridSpacingItemDecoration extends RecyclerView.ItemDecoration {

    private int spacing; // 间距大小

    public GridSpacingItemDecoration(int spacing) {
        this.spacing = spacing;
    }

    @Override
    public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {
        outRect.left = spacing / 2;
        outRect.right = spacing / 2;
        outRect.top = spacing / 2;
        outRect.bottom = spacing / 2;
    }
}

int spacing = getResources().getDimensionPixelSize(R.dimen.spacing); // 间距大小
recyclerView.addItemDecoration(new GridSpacingItemDecoration(spacing));