Question

我有一个类，我用一些按钮定义了一个回收站视图。在相对适配器中，我为每个按钮添加一个onClick方法。从onClick方法，我需要在另一个活动中调用一个方法。我能怎么做？我尝试了这个但是它没有用，除非我在第一个活动中调用该方法。

第一个活动，我宣布使用RecyclerView：

公共类Classici_Tab扩展了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;
}
}

}

适配器：

public class BookListAdapter extends RecyclerView.Adapter<BookListAdapter.BookViewHolder> {

    static Drawable borrow_top;
    static Drawable reserve_top;

    public BookListAdapter()
    {}

    // View Holder
    class BookViewHolder extends RecyclerView.ViewHolder
    {
        public final Button borrow;
        public final Button addfavorites;
        final BookListAdapter mAdapter;


        public BookViewHolder(final View itemView, BookListAdapter adapter) {
            super(itemView);
            borrow = (Button)itemView.findViewById(R.id.borrow);
            addfavorites = (Button)itemView.findViewById(R.id.addfavorites);

            this.mAdapter = adapter;

            addfavorites.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    final int cover_book = R.id.cover;
                    final String title_book = title.getText().toString();
                    final String author_book = author.getText().toString();

                    add_to_fav(itemView, new Book(cover_book, title_book, author_book));    //METHOD TO BE CALLED
                }
            });
        }
    }

    private LinkedList<Book> mBookList = new LinkedList<>();            //per Classici_Tab TODO
    private LinkedList<Book> mBookListFavorites = new LinkedList<>();     //per Favorites_page
    private LayoutInflater mInflater;
    boolean isVisible = false;
    public ItemTouchHelper.Callback callback;

    ClickListener clickListener;

    public BookListAdapter(Context context, LinkedList<Book> bookList) {
        mInflater = LayoutInflater.from(context);
        this.mBookList = bookList;
    }

    @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(final BookViewHolder holder, int position) {
       ...
    }

    @Override
    public int getItemCount() {
        ...
    }

    //INTERFACE TO CALL THE METHOD (IN THE SECOND ACTIVITY)
    public void setClickListener(ClickListener clickListener) {
        this.clickListener = clickListener;
    }

    public void add_to_fav(View v, Book book)
    {
        if(clickListener != null)
        {
            clickListener.itemClicked(v, book);
        }
    }

    public interface ClickListener
    {
        void itemClicked(View view, Book book);
    }
}

第二个活动，我宣布方法：

public class Favorites_Page extends Activity implements BookListAdapter.ClickListener {

    RecyclerView favorites_rv;
    BookListAdapter mAdapter_List;
    LinkedList<Book> favorites = new LinkedList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.favorites_page);

        favorites_rv = (RecyclerView)findViewById(R.id.favorites_rv);
        favorites_rv.setAdapter(mAdapter);
        favorites_rv.setLayoutManager(new LinearLayoutManager(this));

        mAdapter_List = new BookListAdapter();
        mAdapter_List.clickListener = (BookListAdapter.ClickListener)this;
    }


    @Override
    public void itemClicked(View view, Book book) {
        Toast.makeText(getApplicationContext(), "the method has been called successfully", Toast.LENGTH_SHORT).show();
    }
}

Answer 1

您需要序列化才能在两个活动之间进行通信。例如：

addfavorites.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final int cover_book = R.id.cover;
            final String title_book = title.getText().toString();
            final String author_book = author.getText().toString();

            Intent intent = new Intent( CurrentActivityClass.this, Favorites_Page.class )
            intent.putExtra(Favorites_Page.KEY_BOOK , Book) // Book need to implements Parcelable (or Serializable if all content is Serializable)
           CurrentActivityClass.this.startActivity(intent)
        }
    });

然后从您的fav活动中获得如下数据：

public class Favorites_Page extends Activity {

    public static final String KEY_BOOK = "book"
    RecyclerView favorites_rv;
    BookListAdapter mAdapter_List;
    LinkedList<Book> favorites = new LinkedList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.favorites_page);

        ...

        Book book = getIntent().getExtra(KEY_BOOK)
        ...
    }
...

适配器调用Activity方法（ViewHolder）

1 个答案: