Non-static field cannot be referenced from a static context
<p>I have a class as static with some attributes, the class is static, but I'm getting the error that the fields are not static. </p>

<p>I can't figure out for a solution, the examples I see looks like very similar. The view holder always are inside adapter as <strong>static</strong> or <strong>public static</strong></p>

<p>Here is my ArrayAdapter:</p>

<pre><code>public class NoteAdapter extends ArrayAdapter&lt;Note&gt; {

public static class ViewHolder{
    TextView noteTitle;
    TextView noteBody;
    ImageView noteIcon;
}

public NoteAdapter(Context context, ArrayList&lt;Note&gt; notes) {
    super(context, 0, notes);
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    Note note = getItem(position);
    ViewHolder viewHolder;

    if (convertView == null) {
        viewHolder = new ViewHolder();
        convertView = LayoutInflater.from(getContext()).inflate(R.layout.list_row, parent, false);

        // == Here I am getting the error == 
        ViewHolder.noteTitle = (TextView) convertView.findViewById(R.id.text_item_note_title);
        ViewHolder.noteBody = (TextView) convertView.findViewById(R.id.text_item_note_body);
        ViewHolder.noteIcon = (ImageView) convertView.findViewById(R.id.image_item_note);

        convertView.setTag(viewHolder);
    }

    return convertView;
}
</code></pre>

<p>}</p>

<p>Here is my note model:</p>

<pre><code>public class Note {
    private String title, message;
    private long noteId, dateCreateMilli;
    private Category category;

    public enum Category {PERSONAL, TECHNICAL, QUOTE, FINANCE}

    public Note(String title, String message, Category category) {
        this.title = title;
        this.message = message;
        this.category = category;
        this.noteId = 0;
        this.dateCreateMilli = 0;
    }

    public Note(String title, String message, Category category, long noteId, long dateCreateMilli) {
        this.title = title;
        this.message = message;
        this.category = category;
        this.noteId = noteId;
        this.dateCreateMilli = dateCreateMilli;
    }

    public String getTitle() {
        return this.title;
    }

    public String getMessage() {
        return this.message;
    }

    public long getNoteId() {
        return this.noteId;
    }

    public long getDateCreateMilli() {
        return this.dateCreateMilli;
    }

    public Category getCategory() {
        return this.category;
    }

    public TextDrawable getIconResource() {
        return TextDrawable.builder().buildRound("P", android.R.color.darker_gray);
    }
}
</code></pre>

<p>I will appreciate your help. Thanks in advance.</p>