java - 将图像传递给同一类中的另一个函数

Question

三天来我一直在寻找解决方案。如果大家有idea请帮帮我，我什至不认为实现起来有那么难，但它不是我的分支，如果你能这样说的话。

在包含多个项目的列表的 RecyclerView 中，每个项目都有一个标题 (TextView) 和一个封面图像 (ImageView)。

此数据在 Adapter 中设置，在 ViewHolder 中，更具体地说是在 OnBind 函数中设置。

那么我的问题在哪里呢？我创建了一个弹出窗口，其中除了几个按钮外，还包含一个占位符 ImageView 和一个占位符 TextView。我似乎无法找到一种方法将单击项目的数据放在占位符内的列表中。我认为它类似于 OnBind 方法，但它不起作用。

这是适配器(如果需要 GameItem 的代码，我很乐意发布):

import java.util.ArrayList;

public class GameViewAdapter extends RecyclerView.Adapter<GameViewAdapter.GameViewHolder> {
    private ArrayList<GameItem> mGameList;
    private OnItemClickListener mListener;

    public interface OnItemClickListener{
        void onGameClick(int position);
    }
    public void setOnItemClickListener(OnItemClickListener listener){
        mListener =listener;
    }
    public static class GameViewHolder extends RecyclerView.ViewHolder{
        public ImageView Cover;
        public TextView Title;
        public TextView Description;
        public PopupWindow popupWindow;
        public ImageView popUpImage;
        public TextView PopUpTitle;
        public EditText customAmount;
        public Button add;
        private Button addcustom;
        private  Button exit;

        public GameViewHolder(final View itemView, final OnItemClickListener listener) {
            super(itemView);
            add = itemView.findViewById(R.id.addaverage);
            addcustom = itemView.findViewById(R.id.addcustom);
            popUpImage = itemView.findViewById(R.id.popupimg);
            PopUpTitle = itemView.findViewById(R.id.popuptitle);
            customAmount = itemView.findViewById(R.id.gameamount);
            Cover = itemView.findViewById(R.id.GameCover);
            Title = itemView.findViewById(R.id.GameTitle);
            Description = itemView.findViewById(R.id.GameAmount);
            exit = itemView.findViewById(R.id.exit);

            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    showPopUp();
                }
            });
        }

        public void showPopUp() {
            final View popupView = LayoutInflater.from(itemView.getContext()).inflate(R.layout.popup, null);
            final PopupWindow popupWindow = new PopupWindow(popupView, WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT);
            exit = popupView.findViewById(R.id.exit);
            exit.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    popupWindow.dismiss();
                }
            });
            popupWindow.showAtLocation(popupView, Gravity.CENTER, 0, 0);

        }
    }

    public GameViewAdapter(ArrayList<GameItem> gameList){
        mGameList = gameList;
    }





    @Override
    public GameViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        Context context = viewGroup.getContext();
        View v = LayoutInflater.from(context).inflate(R.layout.game_entry, viewGroup, false);
        GameViewHolder GVH = new GameViewHolder(v, mListener);
        return GVH;
    }


        @Override
    public void onBindViewHolder(@NonNull GameViewHolder gameViewHolder, int position){
        GameItem currentItem = mGameList.get(position);
        Glide.with(gameViewHolder.Cover).load(currentItem.getCover()).into(gameViewHolder.Cover);
        gameViewHolder.Title.setText(currentItem.getTitle());
        gameViewHolder.Description.setText(currentItem.getDescription());

    }

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

Answer 1

In the OnBind method, the Image and Text are associated to the Items correctly, through Glide and gameViewHolder.Title.setText(currentItem.getTitle());. Now, I have created a PopUp, which should get the Image and the Text from the clicked item in the RecyclerView.

为了清楚起见，我重新排列了一些方法和属性，接下来，我将进行解释。

public class GameViewAdapter extends RecyclerView.Adapter<GameViewAdapter.GameViewHolder> {

    private ArrayList<GameItem> mGameList;
    private OnItemClickListener mListener;

    public GameViewAdapter(ArrayList<GameItem> mGameList, GameViewAdapter.OnItemClickListener mListener) {
        this.mGameList = mGameList;
        this.mListener = mListener;
    }

    @Override
    public GameViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        Context context = viewGroup.getContext();
        View v = LayoutInflater.from(context).inflate(R.layout.game_entry, viewGroup, false);
        GameViewHolder GVH = new GameViewHolder(v, mListener);
        return GVH;
    }

    @Override
    public void onBindViewHolder(@NonNull GameViewHolder gameViewHolder, int position){
        gameViewHolder.bind(mGameList.get(position));
    }

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

    class GameViewHolder extends RecyclerView.ViewHolder {

        private ImageView itemCover;
        private TextView itemTitle;
        private TextView itemDescription;
        private PopupWindow popupWindow;
        private ImageView popUpImage;
        private TextView PopUpTitle;
        private EditText customAmount;
        private Button add;
        private Button addcustom;
        private Button exit;

        public GameViewHolder(View itemView, GameViewAdapter.OnItemClickListener mListener) {
            super(itemView);
            setupViews(itemView);
        }

        public void bind(GameItem gameItem) {
            Glide.with(this.itemCover).load(gameItem.getCover()).into(this.itemCover);
            this.itemTitle.setText(gameItem.getTitle());
            this.itemDescription.setText(gameItem.getDescription());
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    showPopUp(itemView, gameItem);
                }
            });
        }

        private void setupViews(View itemView) {
            add = itemView.findViewById(R.id.addaverage);
            addcustom = itemView.findViewById(R.id.addcustom);
            popUpImage = itemView.findViewById(R.id.popupimg);
            PopUpTitle = itemView.findViewById(R.id.popuptitle);
            customAmount = itemView.findViewById(R.id.gameamount);
            itemCover = itemView.findViewById(R.id.GameCover);
            itemTitle = itemView.findViewById(R.id.GameTitle);
            itemDescription = itemView.findViewById(R.id.GameAmount);
            exit = itemView.findViewById(R.id.exit);
        }

        private void showPopUp(View itemView, GameItem gameItem) {
            final View popupView = LayoutInflater.from(itemView.getContext()).inflate(R.layout.popup, null);
            final PopupWindow popupWindow = new PopupWindow(popupView, WindowManager.LayoutParams.WRAP_CONTENT, WindowManager.LayoutParams.WRAP_CONTENT);

            final ImageView popupItemCover = popupView.findViewById(R.id.popupItemCover);
            final TextView popupItemTitle = popupView.findViewById(R.id.popupItemTitle);

            Glide.with(popupItemCover).load(gameItem.getCover()).into(popupItemCover);
            popupItemTitle.setText(gameItem.getTitle());

            exit = popupView.findViewById(R.id.exit);
            exit.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    popupWindow.dismiss();
                }
            });
            popupWindow.showAtLocation(popupView, Gravity.CENTER, 0, 0);
        }

    }

    public interface OnItemClickListener{
        void onGameClick(int position);
    }
}

发生了什么变化？首先，我们现在在 ViewHolder 中有一个名为 bind 的方法，我们负责设置来自 Adapter 的数据并将其委托(delegate)给ViewHolder。其次，由于每次调用 onBindViewHolder 时都会调用该方法，因此您将拥有实际的 GameItem。所以？对于该项目，我们现在在 bind 方法中设置它，而不是在 GameViewHolder 构造函数中设置 onClickListener 以打开 PopUp。但是，它有什么好处呢？每次我们将数据绑定(bind)到它的 View 时，我们都会准备我们的 Popup 然后显示它。

应该改变什么？我想，出于性能目的，您应该实例化构造函数，然后每次都用新数据填充它，而不是每次调用 onBindViewHolder 时都重新创建一个新实例。

编辑:由于我不知道您的弹出 View ID，因此我创建了一些虚拟 ID。希望你明白。

最好的。