RecyclerVIew 中使用 GridLayoutManger 的装饰间距和跨度

Question

I am trying to implement this kind of RecyclerView by using GridLayoutMangaer as its layout. However, I am facing the issue while implementing the item spacing for each item in the grid.

My aim is to have an implementation like image below

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Any solutions for this kind of implementation would be appreciated

Answer 1

        public class GridRec extends RecyclerView.ItemDecoration {
          private int space;
        
          public GridRec(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;
        
            if (parent.getChildLayoutPosition(view) == 0) {
                outRect.top = space;
            } else {
                outRect.top = 0;
            }
          }
        }
        
        
        int my_space = getResources().getDimension(R.dimen.test);
        myRecyclerView.addItemDecoration(new GridRec(my_space));
    
    
    
    
    
    
    
    
    
    
    
    
    
    
    -----------------------------------------------------------
    
 


public class abc extends RecyclerView.ItemDecoration {

    private int myPadding_psx;
    private int myPadding_edge_psx;

    public abc(Activity activity) {
        final Resources resources = activity.getResources();
        myPadding_psx = (int) resources.getDimension(R.dimen.myDefault);
        myPadding_edge_psx = (int) resources.getDimension(R.dimen.mYDefaultEdge);
    }

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

        final int itemPosition = parent.getChildAdapterPosition(view);
        if (itemPosition == RecyclerView.NO_POSITION) {
            return;
        }
        int orientation = getOrientation(parent);
        final int itemCount = state.getItemCount();

        int left = 0;
        int top = 0;
        int right = 0;
        int bottom = 0;

        //Horizontal
        if (orientation == LinearLayoutManager.HORIZONTAL) {
            left = myPadding_psx;
            right =myPadding_psx;

            if (itemPosition == 0) {
                left += myPadding_edge_psx;
            }

            else if (itemCount > 0 && itemPosition == itemCount - 1) {
                right += myPadding_edge_psx;
            }
        }

        //Vertical
        else {
            top = myPadding_psx;
            bottom = myPadding_psx;

            if (itemPosition == 0) {
                top += myPadding_edge_psx;
            }
            else if (itemCount > 0 && itemPosition == itemCount - 1) {
                bottom += myPadding_edge_psx;
            }
        }

        if (!isReverseLayout(parent)) {
            outRect.set(left, top, right, bottom);
        } else {
            outRect.set(right, bottom, left, top);
        }
    }

    private boolean isReverseLayout(RecyclerView parent) {
        if (parent.getLayoutManager() instanceof LinearLayoutManager) {
            LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
            return layoutManager.getReverseLayout();
        } else {
            throw new IllegalStateException("Error.");
        }
    }

    private int getOrientation(RecyclerView parent) {
        if (parent.getLayoutManager() instanceof LinearLayoutManager) {
            LinearLayoutManager layoutManager = (LinearLayoutManager) parent.getLayoutManager();
            return layoutManager.getOrientation();
        } else {
            throw new IllegalStateException("Error.");
        }
    }
}