i tried create a matlab gui using a axes and a turn on button using an example i got from mathwork. However it give me these errors which i cannot fix. Can anyone tell me what happen?
Reference to non-existent field 'txtInfo'.
Error in realtime21>btnPreviewVideo_Callback (line 100) set(handles.txtInfo, 'string', errorMessage);
Error in gui_mainfcn (line 96) feval(varargin{:});
Error in realtime21 (line 42) gui_mainfcn(gui_State, varargin{:});
Error in @(hObject,eventdata)realtime21('btnPreviewVideo_Callback',hObject,eventdata,guidata(hObject))
Error while evaluating uicontrol Callback
the code
function varargout = realtime21(varargin)
% REALTIME21 MATLAB code for realtime21.fig
% REALTIME21, by itself, creates a new REALTIME21 or raises the existing
% singleton*.
%
% H = REALTIME21 returns the handle to a new REALTIME21 or the handle to
% the existing singleton*.
%
% REALTIME21('CALLBACK',hObject,eventData,handles,...) calls the local
% function named CALLBACK in REALTIME21.M with the given input arguments.
%
% REALTIME21('Property','Value',...) creates a new REALTIME21 or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before realtime21_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to realtime21_OpeningFcn via varargin.
%
% *See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one
% instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES
% Edit the above text to modify the response to help realtime21
% Last Modified by GUIDE v2.5 28-Apr-2015 11:02:05
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name', mfilename, ...
'gui_Singleton', gui_Singleton, ...
'gui_OpeningFcn', @realtime21_OpeningFcn, ...
'gui_OutputFcn', @realtime21_OutputFcn, ...
'gui_LayoutFcn', [] , ...
'gui_Callback', []);
if nargin && ischar(varargin{1})
gui_State.gui_Callback = str2func(varargin{1});
end
if nargout
[varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
gui_mainfcn(gui_State, varargin{:});
end
% End initialization code - DO NOT EDIT
% --- Executes just before realtime21 is made visible.
function realtime21_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% varargin command line arguments to realtime21 (see VARARGIN)
% Choose default command line output for realtime21
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
% UIWAIT makes realtime21 wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = realtime21_OutputFcn(hObject, eventdata, handles)
% varargout cell array for returning output args (see VARARGOUT);
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Get default command line output from handles structure
varargout{1} = handles.output;
% --- Executes on button press in btnPreviewVideo.
function btnPreviewVideo_Callback(hObject, eventdata, handles)
% hObject handle to btnPreviewVideo (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Initialize the video camera.
global vidobj; % Video camera object.
try
% Initialize Logitech webcam
vidobj = videoinput('winvideo', 1, 'YUY2_320x240');
if ~isempty(vidobj)
src = getselectedsource(vidobj);
vidobj.FramesPerTrigger = 1;
axes(handles.axesImage);
hImage = findobj(handles.axesImage, 'Type', 'image');
preview(vidobj, hImage);
% src.ZoomMode = 'manual';
% Turn on the live video preview. Display the bounding box over it if there is one selected.
TurnOnLiveVideo(handles);
end
% Turn on the live video preview. Display the bounding box over it if there is one selected.
TurnOnLiveVideo(handles);
catch ME
errorMessage = sprintf('Error in function logitech_webcam_OpeningFcn.\nNo Logitech webcam detected!\n\nError Message:\n%s', ME.message);
set(handles.txtInfo, 'string', errorMessage);
uiwait(warndlg(errorMessage));
end
%=====================================================================
% Turn on the live video preview. Display the bounding box over it if there is one selected.
function TurnOnLiveVideo(handles)
global vidobj; % Video camera object.
% Bail out if there is no video object class instantiated.
if isempty(vidobj), return, end;
% Switch the current graphic axes to handles.axesImage.
% This is where we want the video to go.
axes(handles.axesImage);
% Reset image magnification. Required if you ever displayed an image
% in the axes that was not the same size as your webcam image.
hold off;
axis auto;
% Get the handle to the image in the axes.
hImage = findobj(handles.axesImage, 'Type', 'image');
% Turn on the live video.
preview(vidobj, hImage);
% Put hold on so that displaying our bounding box doesn't blow away the image.
hold on;
% Retrieve our x,y coordinates of the bounding box corners.
GetImageMask(handles);
% They have been previously set elsewhere as global variables.
global maskVerticesXCoordinates;
global maskVerticesYCoordinates;
if ~(isempty(maskVerticesXCoordinates) || isempty(maskVerticesYCoordinates))
% If the bounding box coordinates exist,
% plot the bounding box over the live video.
plot(maskVerticesXCoordinates, maskVerticesYCoordinates);
end
% stoppreview(vidobj);
return; % from TurnOnLiveVideo
