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Android Build a Self-Destructing Message Android App Retrieving and Viewing Messages Creating a Custom List Adapter for Messages

Jie Ding
Jie Ding
4,839 Points
Posted by Jie Ding
Jie Ding
4,839 Points

Why my Ribbit could not be launched after adding the custom MessageAdapter?

My code is exactly the same as in the lecture of "Creating a custom list adapter for messages", but it goes to error. From the logcat, the error comes from the NullPointerException from the getView() method in the MessageAdapter class. I still do not know why. Can anyone help me? I really appreciate your help!

1 Answer

Jie Ding
Jie Ding
4,839 Points
Jie Ding
Jie Ding
4,839 Points

OK I have solved the issue. I modified the getView() methods provided in the lecture to the following code. Hope it will help someone with similar problems.

@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View rowView = convertView;

        if (rowView == null) {
            rowView = LayoutInflater.from(mContext).inflate(R.layout.message_item, null);
            ViewHolder viewHolder = new ViewHolder();
            viewHolder.iconImageView = (ImageView) rowView.findViewById(R.id.message_icon);
            viewHolder.nameLabel = (TextView) rowView.findViewById(R.id.sender_label);
            rowView.setTag(viewHolder);
        }

        ViewHolder holder = (ViewHolder) rowView.getTag(); 

        ParseObject message = mMessages.get(position);

        if (message.getString(ParseConstants.KEY_FILE_TYPE).equals(ParseConstants.TYPE_IMAGE)) {
            holder.iconImageView.setImageResource(R.drawable.ic_action_picture);
        }
        else {
            holder.iconImageView.setImageResource(R.drawable.ic_action_play_over_video);
        }
        holder.nameLabel.setText(message.getString(ParseConstants.KEY_SENDER_NAME));

        return rowView;
    }