RecyclerView沒有可以直接設定間距的屬性，但可以用ItemDecoration來裝飾一個item，所以繼承重寫ItemDecoration就可以實現間距了

public classSpaceItemDecorationextendsRecyclerView.ItemDecoration{  
  
        private int space;  
  
        public SpaceItemDecoration(int space) {  
            this.space = space;  
        }  
  
        @Override
 
  
        public void getItemOffsets(Rect outRect, View view, RecyclerView parent, RecyclerView.State state) {  
  
            if(parent.getChildPosition(view) != 0)  
                outRect.top = space;  
        }  
    }

int spacingInPixels = getResources().getDimensionPixelSize(R.dimen.space);
 mRecyclerView.addItemDecoration(new
 
 SpaceItemDecoration(spacingInPixels));