android - 在自定义 TextWatcher 中更新 Adapter/RecyclerView

Question

我正在尝试通过自定义 TextWatcher 在我的 RecyclerView 中添加/删除 一个项目。

这是我的自定义文本观察器的一部分

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
    //get the position and size from edit text
    int position = (int) editText.getTag(R.string.position);
    int size = (int) editText.getTag(R.string.listSize);

    //if the character count equals 1
    if (count == 1){
        //check if the current position is proven to be the last item in the list
        if (position + 1 == size){
            //add an item to the list here

        }
    } 
}

它说“在此处向适配器列表添加一个项目”我想将一个项目添加到我的 recyclerview 并更新适配器。

我很确定没有办法轻松做到这一点。我是否需要使用 Singleton 设计模式 进行设置，或者有什么方法可以在我的 MainActivity 上创建一个自定义监听器，当我想添加一个元素？

我也在使用自定义适配器，如果有人需要，我可以发布。

**使用我的自定义适配器更新

public class PlayerAdapter extends RecyclerView.Adapter<PlayerAdapter.PlayerHolder>{

    private List<Players> playerList;

    public PlayerAdapter(List<Players> list) {
        playerList = list;
    }

    /* ViewHolder for each item */
    public class PlayerHolder extends RecyclerView.ViewHolder  {

        EditText playerName;

        PlayerHolder(View itemView) {
            super(itemView);
            Log.e("Holder","setview");
            playerName = itemView.findViewById(R.id.name);
            MyTextWatcher textWatcher = new MyTextWatcher(playerName);
            playerName.addTextChangedListener(textWatcher);
        }
    }

    @Override
    public PlayerHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View itemView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.new_player_item_layout, parent, false);
        return new PlayerHolder(itemView);
    }

    @Override
    public void onBindViewHolder(PlayerHolder holder, int position) {
        Players playerItem = playerList.get(position);

        //Sets Text
        //holder.playerName.setText(playerItem.getName());
        holder.playerName.setTag(R.string.listSize, playerList.size());
        holder.playerName.setTag(R.string.position, position);
    }

    @Override
    public int getItemCount() {
        return playerList.size();
    }

    public void updateList(List<Players> newList){
        playerList = newList;
        notifyDataSetChanged();
    }
}

Answer 1

编辑:添加而不是更新你想要的是一个接口(interface)来连接 TextWatcher 和 RecyclerView 的逻辑例如，您可以拥有此界面，但您可以根据需要修改它。

interface AddPlayerInterface {
    private void addPlayer(Player player);
}

您可以在您的 Adapter 中实现它例如

    class Adapter extends RecyclerView.Adapter implements AddPlayerInterface {
        // ... your other adapter implementation codes

        @override
        private void addPlayer(Player player) {
            // here you can add the new player to the list
            list.add(player);
            notifyDataSetChanged(); // or any of the helper methods to notify adapter of change like for specific rows
        }

    }

然后您通过

将您的监听器引用传递给textwatcher

@Override
public PlayerHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.new_player_item_layout, parent, false);


    return new PlayerHolder(itemView, listener);
}

您的 textwatcher 将包含对要调用的接口(interface)的引用 类 CustomWatcher 实现 TextWatcher { protected Player 播放器； 私有(private) AddPlayerInterface 监听器；

   private CustomWatcher(Player player, AddPlayerInterface interface)
   {
       this.player = player;
       this.listener = interface;
   }

   @Override
   public void afterTextChanged(Editable editable)
   {
        // if you want it on after textchanged you'd call it here and you would probably create the new player instance here
       Player player = new Player();
       listener.addPlayer(player); // this would call the listener implementation on your adapter 

   }
}