java - Android: Implementing ViewHolder

Question

I am trying to implement ViewHolder in my Android app, but I keep getting that ViewHolder cannot be resolved to a type, without any suggestions for an import. Anyone know how to get around this?

Answer 1

That's because a ViewHolder is not a class that is from the Android SDK, you make it yourself. Based on what I can find, a ViewHolder is an implementation that stores Views (per row in a ListView usually) for a larger area, so it is a sort of helper class and cache mechanism. This is one example I found on Android Developers of what a ViewHolder would contain.

static class ViewHolder {
  TextView text;
  TextView timestamp;
  ImageView icon;
  ProgressBar progress;
  int position;
}

Then you can implement it in a ListAdapter or a similar class.