Android Fragments 删除项目后RecyclerView不更新[重复]

kr98yfug  于 2022-12-19  发布在  Android
关注(0)|答案(7)|浏览(156)
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How to update RecyclerView Adapter Data(16个答案)
去年关闭了。
我在一个片段的底部有一个RecyclerView的水平图像滑块,片段的顶部显示了一些细节,一旦用户点击底部的图像,我们的想法是从图像滑块中删除该图像,并在片段中显示其信息。现在信息显示出来,但图像没有从RecyclerView中删除。这是我在最外层布局的Onclick中编写的代码。我尝试了所有相关的答案,但没有找到任何答案。它们都在代码中。请让我知道我做错了什么或缺少了什么。

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);
    }
}

}

2w3kk1z5

2w3kk1z51#

您需要使用这3行才能使其工作

mItemList.remove(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, mItemList.size());
9w11ddsr

9w11ddsr2#

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

qzwqbdag3#

在自定义RecylerView.Adapter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());
}

以及从MainActivity调用:

adapter.deleteData(position);
9njqaruj

9njqaruj4#

为了使代码正常工作,您需要按如下方式更改Adapter构造函数实现:

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

然后在onActivityResult中执行以下操作:

@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();
    }
}
slhcrj9b

slhcrj9b5#

不需要在那里做这么多复杂的事情,只需删除和通知

holder.itemRowRelativeLayout.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (isFiltering) {
            mItemList.remove(position);
            notifyItemRemoved(position);
        }
    }
});
gzszwxb4

gzszwxb46#

只加这两行

mItemList.remove(position);
notifyDataSetChanged();
b4lqfgs4

b4lqfgs47#

您需要使用这些行才能使其工作

mItemList.remove(position);
notifyDataSetChanged();

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