Question

我写了一个RecyclerView，可以拖动其中的项目。当我拖动项目随机移动。然后我看到数据，适配器中数据的顺序和RecyclerView中显示的数据顺序是不一样的？为什么，谁能帮帮我？代码如下：

@Override
public int getMovementFlags(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder) {
    int dragFlag, swipeFlag;
    RecyclerView.LayoutManager layoutManager = recyclerView.getLayoutManager();
    if (layoutManager instanceof GridLayoutManager) {
        dragFlag = ItemTouchHelper.DOWN | ItemTouchHelper.UP | ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT;
        swipeFlag = 0;
    } else {
        dragFlag = ItemTouchHelper.DOWN | ItemTouchHelper.UP;
        swipeFlag = ItemTouchHelper.END;
    }
    return makeMovementFlags(dragFlag, swipeFlag);
}

@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
    int fromPosi = viewHolder.getAdapterPosition();
    int toPosi = target.getAdapterPosition();
    adapter.move(fromPosi, toPosi);
    EventBus.getDefault().post(new EventMessage(ModifyMainMenuActivity.class.getSimpleName()));
    return true;
}

****并且遵循适配器***

public class ShopDecorationAdapter extends 
  BaseRecyclerViewAdapter<ProductListResponse.ProductItem> {

private int imageHeight, imageWidth;

public ShopDecorationAdapter(Context context, int layout, OnItemClickListener onItemClickListener) {
    super(context, layout, onItemClickListener);
}

public void setImageSize(int imgH, int imgW) {
    this.imageHeight = imgH;
    this.imageWidth = imgW;
}

@Override
protected void bindData(BaseViewHolder holder, ProductListResponse.ProductItem data, int position) {
    holder.getTextView(R.id.tv_product_name).setText(data.name);
    ViewGroup.LayoutParams imgLayoutParam = holder.getImageView(R.id.product_icon).getLayoutParams();
    imgLayoutParam.height = imageHeight;
    imgLayoutParam.width = imageWidth;
    holder.getItemView().setLayoutParams(imgLayoutParam);
    holder.getImageView(R.id.product_icon).setLayoutParams(imgLayoutParam);
    if (data.isAddBtn) {
        holder.getTextView(R.id.tv_product_name).setGravity(Gravity.CENTER_HORIZONTAL);

// ImgLoadUtils.loadLocalResourceDrawable（mContext，R.drawable.icon_add_in_teaching_record， // holder.getImageView（R.id.product_icon））; holder.getImageView（R.id.product_icon）.setImageResource（R.drawable.icon_add_in_teaching_record）; holder.getTextView（R.id.tv_product_price）.setVisibility（View.GONE）; } else { holder.getTextView（R.id.tv_product_price）.setVisibility（View.VISIBLE）; holder.getTextView（R.id.tv_product_price）.setText（mContext.getString（R.string.im_product_price，data.zhimaPrice））; ImgLoadUtils.loadIntoUseFitWith（mContext，R.drawable.artisan_icon_miss，EncodeUtils.urlString（data.coverPic），holder.getImageView（R.id.product_icon））; if（data.isSelected＆amp;＆amp;！data.isAddBtn）{ 。holder.getItemView（）setBackgroundResource（R.drawable.bg_cf34270_border1dp_solid_white）;

        } else {
            holder.getItemView().setBackgroundResource(R.drawable.bg_white);
        }
    }

}
public void move(int origin, int target) {
        Collections.swap(datas, origin, target);
        if (origin < target) {
            for (int i = origin; i < target; i++) {
                Collections.swap(datas, i, i + 1);
            }
        }
        if (origin > target) {
            for (int i = origin; i > target; i--) {
                Collections.swap(datas, i, i - 1);
            }
        }
        notifyItemMoved(origin, target);
    }

}

Answer 1

删除不必要的交换

public void move(int origin, int target) {
    //Collections.swap(datas, origin, target);  !!!!!!!!
    if (origin < target) {
        for (int i = origin; i < target; i++) {
            Collections.swap(datas, i, i + 1);
        }
    }
    if (origin > target) {
        for (int i = origin; i > target; i--) {
            Collections.swap(datas, i, i - 1);
        }
    }
    notifyItemMoved(origin, target);
}

Answer 2

转到文件 - >设置 - ＆gt;构建，执行，部署 - ＆gt; Gradle-＆gt;取消选中离线工作选项。

为什么数据排序和recylerview视图排序不同

2 个答案: