在我的
MainActivity.java
中,我有一个类似登录按钮的东西。 我还有4个片段,每个片段都包含一个可回收视图(imageview + textview)。 ImageView是隐藏的,但是当我按下按钮时,它就变得可见了。我该怎么做?在适配器中, notifyDataSetChanged()
不起作用,而且我不能在片段页面上调用它,因为它在 onCreateView
方法外部。以下是我的代码:
MainActivity:包含按钮
片段页面:
public class Classici_Tab extends Fragment {
LinkedList<Book> catalog = new LinkedList<>();
RecyclerView mRecyclerView;
BookListAdapter mAdapter;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View fragmentView = inflater.inflate(R.layout.classici_tab, container, false);
fillCatalog("catalog.csv"); //fill the LinkedList
mRecyclerView = (RecyclerView) fragmentView.findViewById(R.id.classici_rv);
mAdapter = new BookListAdapter(getContext(), catalog);
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
return fragmentView;
}
}
Adapter:
public class BookListAdapter extends RecyclerView.Adapter<BookListAdapter.BookViewHolder> {
// View Holder
class BookViewHolder extends RecyclerView.ViewHolder
{
public final ImageView cover;
public final TextView title;
public final TextView author;
public final ImageView availability;
final BookListAdapter mAdapter;
public BookViewHolder(View itemView, BookListAdapter adapter) {
super(itemView);
cover = (ImageView) itemView.findViewById(R.id.cover);
title = (TextView) itemView.findViewById(R.id.title);
author = (TextView) itemView.findViewById(R.id.author);
availability = (ImageView) itemView.findViewById(R.id.availability);
MainActivity m = new MainActivity();
if(m.loggedin) availability.setVisibility(View.VISIBLE);
else availability.setVisibility(View.INVISIBLE);
this.mAdapter = adapter;
}
}
private LinkedList<Book> mBookList = new LinkedList<>();
private LayoutInflater mInflater;
boolean isVisible = false;
public BookListAdapter() {}
public BookListAdapter(Context context, LinkedList<Book> bookList) {
mInflater = LayoutInflater.from(context);
this.mBookList = bookList;
}
//IT DOESN'T WORK
public void setPicturesVisibility(boolean isVisible){
this.isVisible = true;
notifyDataSetChanged();
}
@Override
public BookViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View mItemView = mInflater.inflate(R.layout.tab_list_item, parent, false);
return new BookViewHolder(mItemView, this);
}
@Override
public void onBindViewHolder(BookViewHolder holder, int position) {
holder.cover.setImageResource(mBookList.get(position).getCover());
holder.title.setText(mBookList.get(position).getTitle());
holder.author.setText(mBookList.get(position).getAuthor());
holder.availability.setImageResource(mBookList.get(position).getAvailability());
if(isVisible){
holder.availability.setVisibility(View.VISIBLE);
}else{
holder.availability.setVisibility(View.INVISIBLE);
}
}
@Override
public int getItemCount() {
return mBookList.size();
}
}