将位图从列表视图适配器传递到片段奇怪的行为

Question

将位图从列表视图中的网络图像视图传递到片段时，我遇到了一些奇怪的行为。

我从列表视图适配器中的 url 加载图像，然后当点击列表视图项时，该列表视图中的图像然后用作片段中的背景。但是，当我这样做时，片段中显示了错误的图像，显​​示的图像是当前在屏幕上可见的列表视图底部的项目。

这是我的适配器设置列表视图：

public class EventListAdapter extends BaseAdapter {

Context context;
public static ArrayList<EventObject> eventList;
private LayoutInflater mInflater;
private Bitmap bitmap;
private NetworkImageView img_main;
private RelativeLayout layoutItem;
private TextView txt_event_name;
private TextView txt_event_details;

public EventListAdapter(Context context, ArrayList<EventObject> eventList) {
    this.context = context;
    this.eventList = eventList;
    mInflater = LayoutInflater.from(context);
}


public void addItems(ArrayList<EventObject> eventList) {
    this.eventList.addAll(eventList);
    notifyDataSetChanged();
}

@Override
public int getCount() {
    return eventList.size();
}

@Override
public Object getItem(int position) {
    return eventList.get(position);
}

@Override
public long getItemId(int position) {
    return 0;
}

@SuppressLint("all")
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    try {
        // reuse of convertView
        if (convertView == null) {
            layoutItem = (RelativeLayout) mInflater.inflate(R.layout.view_event_list_item, parent, false);
        } else {
            layoutItem = (RelativeLayout) convertView;
        }

        img_main = (NetworkImageView) layoutItem.findViewById(R.id.img_main);
        txt_event_details = (TextView) layoutItem.findViewById(R.id.txt_event_details);
        txt_event_name = (TextView) layoutItem.findViewById(R.id.txt_event_name);

        txt_event_name.setTypeface(FontClass.getOpenSansRegular(context));
        txt_event_details.setTypeface(FontClass.getOpenSansLight(context));

        img_main.setDefaultImageResId(R.drawable.ic_weekends_matter_black);
        img_main.setImageUrl(eventList.get(position).getImageUrl(), new ImageLoader(NetworkManager.getInstance().requestQueue, new LruBitmapCache()));

        txt_event_name.setText(eventList.get(position).getEventName());
        txt_event_details.setText(eventList.get(position).getVenueName() + ", " + getFormattedDate(eventList.get(position).getEventDate()));

        layoutItem.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                ((HomeActivity) context).setEventProfileFrag(eventList.get(position).getFullJsonObject(), ((BitmapDrawable)img_main.getDrawable()).getBitmap());
            }
        });

    } catch (Exception e) {
        e.printStackTrace();
    }

    notifyDataSetChanged();
    return layoutItem;
}

private String getFormattedDate(String dateString) throws ParseException {

    //"2016-06-27 16:00:00"
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd", Locale.UK);
    Date newDate = format.parse(dateString);

    format = new SimpleDateFormat("EEEE dd MMMM", Locale.UK);
    String date = format.format(newDate);

    return date;
}
}

最后在片段中，我从传入片段的参数中检索图像：

 mParam2 = BitmapFactory.decodeByteArray(getArguments().getByteArray(ARG_PARAM2), 0, getArguments().getByteArray(ARG_PARAM2).length);

img_header.setImageBitmap(mParam2);

Answer 1

用下面的替换你的适配器类，它可能会起作用：

 public class EventListAdapter extends BaseAdapter {

      Context context;
      public static ArrayList<EventObject> eventList;
      private LayoutInflater mInflater;
      private Bitmap bitmap;
      private NetworkImageView img_main;

      class ViewHolder{

      private RelativeLayout layoutItem;
      private TextView txt_event_name;
      private TextView txt_event_details;
      }

      public EventListAdapter(Context context, ArrayList<EventObject> eventList) {
         this.context = context;
          this.eventList = eventList;
          mInflater = LayoutInflater.from(context);
       }


       public void addItems(ArrayList<EventObject> eventList) {
this.eventList.addAll(eventList);
notifyDataSetChanged();
 }

       @Override
        public int getCount() {
return eventList.size();
}

       @Override
   public Object getItem(int position) {
return eventList.get(position);
}

  @Override
 public long getItemId(int position) {
return 0;
}

   @SuppressLint("all")
   @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
try {
    // reuse of convertView
    ViewHolder holder;
            if (convertView == null) {
            holder=new ViewHolder();
            holder.layoutItem = (RelativeLayout) mInflater.inflate(R.layout.view_event_list_item, parent, false);
    } else {
        holder.layoutItem = (RelativeLayout) convertView;
    }

    holder.img_main = (NetworkImageView) layoutItem.findViewById(R.id.img_main);
    holder.txt_event_details = (TextView) layoutItem.findViewById(R.id.txt_event_details);
    holder.txt_event_name = (TextView) layoutItem.findViewById(R.id.txt_event_name);

    holder.txt_event_name.setTypeface(FontClass.getOpenSansRegular(context));
    txt_event_details.setTypeface(FontClass.getOpenSansLight(context));

        holder.img_main.setDefaultImageResId(R.drawable.ic_weekends_matter_black);
    holder.img_main.setImageUrl(eventList.get(position).getImageUrl(), new ImageLoader(NetworkManager.getInstance().requestQueue, new LruBitmapCache()));

    holder.txt_event_name.setText(eventList.get(position).getEventName());
    holder.txt_event_details.setText(eventList.get(position).getVenueName() + ", " + getFormattedDate(eventList.get(position).getEventDate()));

    holder.layoutItem.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            ((HomeActivity) context).setEventProfileFrag(eventList.get(holder.getPosition()).getFullJsonObject(), ((BitmapDrawable)img_main.getDrawable()).getBitmap());
        }
    });

} catch (Exception e) {
    e.printStackTrace();
}

notifyDataSetChanged();
return layoutItem;
}

 private String getFormattedDate(String dateString) throws ParseException {

//"2016-06-27 16:00:00"
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd", Locale.UK);
Date newDate = format.parse(dateString);

format = new SimpleDateFormat("EEEE dd MMMM", Locale.UK);
String date = format.format(newDate);

return date;
}
}