REFERENCE TO NON-EXISTENT FIELD 'labelList'

Matlab is generating the 'reference to non-existent field' error for my code. As below there is the error in my code.

Reference to non-existent field 'labelList'. Error in innalillah>draw_Callback (line 156) num = get(handles.labelList,'Value');

function draw_Callback(hObject, eventdata, handles)
% hObject    handle to draw (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
images = getappdata(0, 'images');
method = getappdata(0, 'method');
img = getappdata(0, 'img');
num = get(handles.labelList,'Value'); %Reference to non-existent field 'labelList'.
buf = [];
if method == 3
  axes(handles.imgArea);
  hold on;
  h = imshow(img);
  replot_seeds(handles);
  hold off;
  e = imfreehand(gca);
  mask = uint8(createMask(e, h));
  switch num
    case 1
      buf = mask;
      if isempty(images.regionOne)
        images.regionOne = buf;
      else
        [xx, yy] = find(buf == num);
        for n = 1:length(xx)
          images.regionOne(xx(n), yy(n)) = num;
        end
      end
    case 2
      buf = mask * num;
      if isempty(images.regionTwo)
        images.regionTwo = buf;
      else
        [xx, yy] = find(buf == 2);
        for n = 1:length(xx)
          images.regionTwo(xx(n), yy(n)) = num;
        end
      end
    case 3
      buf = mask * num;
      if isempty(images.regionThree)
        images.regionThree = buf;
      else
        [xx, yy] = find(buf == 3);
        for n = 1:length(xx)
          images.regionThree(xx(n), yy(n)) = 3;
        end
      end
    case 4
      buf = mask * num;
      if isempty(images.regionFour)
        images.regionFour = buf;
      else
        [xx, yy] = find(buf == num);
        for n = 1:length(xx)
          images.regionFour(xx(n), yy(n)) = num;
        end
      end
    case 5
      buf = mask * num;
      if isempty(images.regionFive)
        images.regionFive = buf;
      else
        [xx, yy] = find(buf == num);
        for n = 1:length(xx)
          images.regionFive(xx(n), yy(n)) = num;
        end
      end
  end
  setappdata(0, 'images', images);
  replot_seeds(handles);
else
  [~,xpts,ypts] = freehanddraw(handles.imgArea,'color',handles.LST{num},'linewidth', 2);
  buf=[xpts,ypts];
  buf = (floor(buf));
  buf(end + 1, :) = NaN;
  switch num
    case 1
      if isempty(images.labelOne)
        images.labelOne = buf;
      else
        label = images.labelOne;
        images.labelOne = double([label;buf]);
      end
    case 2
      if isempty(images.labelTwo)
        images.labelTwo = buf;
      else
        label = images.labelTwo;
        images.labelTwo = double([label;buf]);
      end
    case 3
      if isempty(images.labelThree)
        images.labelThree = buf;
      else
        label = images.labelThree;
                images.labelThree = double([label;buf]);      
end
    case 4
      if isempty(images.labelFour)
        images.labelFour = buf;
      else
        label = images.labelFour;
        images.labelFour = double([label;buf]);
      end
    case 5
      if isempty(images.labelFive)
        images.labelFive = buf;
      else
        label = images.labelFive;
        images.labelFive = double([label;buf]);
      end
    otherwise

  end
end

assignin('base', 'buf', buf);
setappdata(0, 'images', images);
%guidata(gcbo,handles);

Answer 1

[Walter Roberson]

We as outside viewers have no reason to expect that handles.labelList will exist.

You appear to be using GUIDE, and it appears that you are expecting handles.labelList to be the handle of a uicontrol style 'listbox'. Perhaps you have a typing mistake in the name of the control -- for example perhaps it is handles.label_List or handles.labellist . Or perhaps it used to be handles.labelList but you renamed it.