删除项目后,RecyclerView不会更新

时间:2017-07-31 10:24:10

标签: android android-fragments android-recyclerview android-adapter recycler-adapter

我在片段底部有一个RecyclerView水平图像滑块。片段的顶部显示了一些细节。一旦用户点击底部的图像,想法是从图像滑块中删除该图像并在片段中显示其信息。现在信息显示但图像不会从RecyclerView中删除。这是我在最外层布局的Onclick中编码的内容。我已经尝试了所有可以找到的相关答案,但没有任何效果。它们都在代码中。请让我知道我做错了什么或错过了什么。

holder.itemRowRelativeLayout.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            if (isFiltering) {
                mItemList.clear();
                mItemList.addAll(mOriginalItemList);
                mItemList.remove(position);// At this point mItemList holds the correct. That is all the images but not the one that was clicked. 

                notifyItemRemoved(position); //solution 1
                notifyItemRangeRemoved(position, getItemCount()); // solution 2
                notifyItemRangeRemoved(0, getItemCount()); // solution 3
                notifyDataSetChanged();//solution 4
            }
        }
    });

适配器的完整代码

public class ImageGallery16X9Adapter<T extends GalleryItem> extends RecyclerView.Adapter<ImageGallery16X9Adapter.GalleryItemViewHolder> {

public enum GalleryMode {
    All_SAME,
    FIRST_DIFFERENT
}

private Context mContext;
private BasePresenter mPresenter;
private List<T> mItemList;
private List<T> mOriginalItemList;
private GalleryItem mFirstItem;
private GalleryMode mGalleryMode;
private int deviceWidth, itemWidth, marginSingle, marginDouble;
private boolean isFiltering;

public ImageGallery16X9Adapter(Context context, BasePresenter presenter, GalleryMode galleryMode, List<T> itemList, GalleryItem firstItem, boolean isFiltering) {
    mContext = context;
    mPresenter = presenter;
    mGalleryMode = galleryMode;
    mItemList = new ArrayList<>(itemList);
    mOriginalItemList = new ArrayList<>(itemList);
    mFirstItem = firstItem;
    deviceWidth = CommonUtils.getDeviceWidth((Activity) mContext);
    itemWidth = (int) (deviceWidth * 0.9);
    marginDouble = (int) (deviceWidth * 0.05);
    marginSingle = (int) (deviceWidth * 0.025);
    this.isFiltering = isFiltering;
}

@Override
public GalleryItemViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    return new GalleryItemViewHolder(LayoutInflater.from(parent.getContext()).
            inflate(R.layout.row_image_gallery_16x9_item, parent, false));
}

@Override
public void onBindViewHolder(GalleryItemViewHolder holder, final int position) {
    RecyclerView.LayoutParams layoutParams = (RecyclerView.LayoutParams) holder.itemRowRelativeLayout.getLayoutParams();
    RelativeLayout.LayoutParams rlParams = (RelativeLayout.LayoutParams) holder.itemImageView.getLayoutParams();
    layoutParams.width = itemWidth;
    rlParams.height = (int) (layoutParams.width * Constant.HEIGHT_FACTOR_16X9);

    if (position == 0) {
        layoutParams.leftMargin = marginDouble;
        layoutParams.rightMargin = 0;
        if (mGalleryMode == GalleryMode.FIRST_DIFFERENT) {
            holder.itemTitle.setVisibility(View.VISIBLE);
            holder.itemTitle.setText(mFirstItem.getItemTitle());
            if (mFirstItem.getItemImage() != null) {
                Picasso.with(MyApplication.getAppContext()).load(mFirstItem.getItemImage()).fit().placeholder(R.drawable.error_image).error(R.drawable.error_image).into(holder.itemImageView);
            } else {
                Picasso.with(MyApplication.getAppContext()).load(R.drawable.error_image).placeholder(R.drawable.error_image).error(R.drawable.error_image).fit().into(holder.itemImageView);
            }
            holder.itemDescription.setText(mFirstItem.getItemDescription());
        }
    } else {
        if (mGalleryMode == GalleryMode.FIRST_DIFFERENT) {
            if (position == mItemList.size()) {
                layoutParams.rightMargin = marginDouble;
            } else {
                layoutParams.rightMargin = 0;
            }
        } else {
            if (position == mItemList.size() - 1) {
                layoutParams.rightMargin = marginDouble;
            } else {
                layoutParams.rightMargin = 0;
            }
        }
        layoutParams.leftMargin = marginSingle;
    }

    int itemPosition = position;
    if (mGalleryMode == GalleryMode.FIRST_DIFFERENT && position > 0) {
        itemPosition = position - 1;
        T item = mItemList.get(itemPosition);
        holder.itemTitle.setVisibility(View.GONE);
        holder.itemDescription.setText(item.getItemDescription());
        Picasso.with(mContext).load(item.getItemImage()).fit().placeholder(R.drawable.error_image).error(R.drawable.error_image).into(holder.itemImageView);

    } else if (mGalleryMode == GalleryMode.All_SAME) {
        T item = mItemList.get(itemPosition);
        holder.itemTitle.setVisibility(View.GONE);
        holder.itemDescription.setText(item.getItemDescription());
        Picasso.with(mContext).load(item.getItemImage()).fit().placeholder(R.drawable.error_image).error(R.drawable.error_image).into(holder.itemImageView);
    }

    holder.itemRowRelativeLayout.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mGalleryMode == GalleryMode.FIRST_DIFFERENT) {
                if (position == 0) {
                    mPresenter.onItemClicked(mFirstItem);
                } else {
                    mPresenter.onItemClicked(mItemList.get(position - 1));
                }
            } else {
                mPresenter.onItemClicked(mItemList.get(position));
                if (isFiltering) {
                    mItemList.clear();
                    mItemList.addAll(mOriginalItemList);
                    mItemList.remove(position);

                    notifyItemRemoved(position); //solution 1
                    notifyItemRangeRemoved(position, getItemCount()); // solution 2
                    notifyItemRangeRemoved(0, getItemCount()); // solution 3
                    notifyDataSetChanged();//solution 4
                }
            }
        }
    });
}

@Override
public int getItemCount() {
    if (mGalleryMode == GalleryMode.FIRST_DIFFERENT)
        return mItemList.size() + 1;
    else
        return mItemList.size();
}


static class GalleryItemViewHolder extends RecyclerView.ViewHolder {
    private final TextView itemDescription, itemTitle;
    private final ImageView itemImageView, itemFavoriteImageView;
    private final RelativeLayout itemRowRelativeLayout;

    public GalleryItemViewHolder(View itemView) {
        super(itemView);
        itemRowRelativeLayout = (RelativeLayout) itemView.findViewById(R.id.rl_gallery_item_row);
        itemImageView = (ImageView) itemView.findViewById(R.id.img_gallery_item);
        itemFavoriteImageView = (ImageView) itemView.findViewById(R.id.img_gallery_item_favorite);
        itemTitle = (TextView) itemView.findViewById(R.id.txt_gallery_item_name);
        itemDescription = (TextView) itemView.findViewById(R.id.txt_gallery_item_description);
    }
}

}

7 个答案:

答案 0 :(得分:14)

您需要使用这3行才能使其正常工作

mItemList.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, mItemList.size());

答案 1 :(得分:1)

private void removerecyclerItem(DraftStoriesPojo list) {
        int current_position = allStoriesPojoList.indexOf(list);
        allStoriesPojoList.remove(current_position);
        notifyItemRemoved(current_position);
        notifyItemRangeChanged (current_position, getItemCount());
    }

答案 2 :(得分:0)

为了使代码正常工作,您需要更改Adapter构造函数实现,如下所示:

    public RecyclerViewAdapter(Context context, List<Model> model) {
    this.context = context;
    this.model = model;
}

然后在onActivityResult中这样做:

    @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == 4) {
        listModel.clear();
        listModel.addAll(repository.consDataBase(context));
        recyclerViewAdapter.notifyDataSetChanged();
    }
}

答案 3 :(得分:0)

不需要在那里做那么复杂的事情,只需删除并通知

holder.itemRowRelativeLayout.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (isFiltering) {
            mItemList.remove(position);
            notifyItemRemoved(position);
        }
    }
});

答案 4 :(得分:0)

只添加这两行

mItemList.remove(position);
notifyDataSetChanged();

答案 5 :(得分:0)

您需要使用以下几行使其起作用

mItemList.remove(position);
notifyDataSetChanged();

答案 6 :(得分:0)

在自定义RecylerView中声明一个方法,如下所示

public void DeleteData(int position){

        recordingItems.remove(position);
        notifyItemRemoved(position);
        notifyItemRangeChanged(position, recordingItems.size());
    }

并通过mainActivity通话

adapter.DeleteData(position);