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

Posted by Ben Lee
Ben Lee
1,777 Points

message.getString(ParseConstants.KEY_FILE_TYPE) give null pointer exception. anything in that parameter = null

ParseObject message = mMessages.get(position);

    Log.d(TAG,"this is what get string gets: "+ message.getString("ParseConstants.KEY_FILE_TYPE"));
    //if(message.getString(ParseConstants.KEY_FILE_TYPE).equals(ParseConstants.TYPE_VIDEO)) {
        holder.iconImageView.setImageResource(R.mipmap.ic_action_picture);
    //}
    //else{ //if its a video
     //   holder.iconImageView.setImageResource(R.mipmap.ic_action_play_over_video);
    //}

    holder.nameLabel.setText(message.getString(ParseConstants.KEY_SENDER_NAME));
    return convertView;
}

private static class ViewHolder{
    ImageView iconImageView;
    TextView nameLabel;
}

}

like stated in the title, whatever key i use. the value of message.getString is null . I have gone so far as to copy ben's code from every file but the mainActivity file and it still gives me null..... has anyone come across this issue? could it be an issue with Parse.com? To clarify, my cloud has 5 items under the fileType key which are 3 images and 2 videos

Ivan Mcschool
Ivan Mcschool
6,990 Points

I just observed this issue also. It seems the view holder becomes null after initialized once.

1 Answer

Ivan Mcschool
Ivan Mcschool
6,990 Points
Ivan Mcschool
Ivan Mcschool
6,990 Points

Found the bug. 

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

    ViewHolder holder = new ViewHolder();

    if (convertView == null) {
        convertView = LayoutInflater.from(mContext).inflate(R.layout.message_item, null);
        holder.iconImageView = (ImageView) convertView.findViewById(R.id.messageIcon);
        holder.nameLabel = (TextView) convertView.findViewById(R.id.senderLabel);
        //set holder as tag
        convertView.setTag(holder);
    } else{
        holder = (ViewHolder)convertView.getTag();

    }

In the 'else' condition, the line: holder = (ViewHolder)convertView.getTag();

in the above line , calling "convertView.getTag()" without previously calling the corresponding "setTag()" in the 'if' condition.

Adding "convertView.setTag(holder);" after calling "convertView.findViewById(R.id.senderLabel);" in the 'if' condition should do the trick.