How to get data from edit text box in GUI with a push button

Hi,

I am building a GUI with an edit text box and a puch button, and I want to save the data (which is written by the user) from the edit box to a variable when the button is pushed. So I was using this code, but I got the error of:

Attempt to reference field of non-structure array.

Error in untitled>button_send_Callback (line 105) data = get(handles.datatosend, 'String');

The code: global data; data = get(handles.datatosend, 'String');

I have no idea what can be the problem. Thank you for helping.

[Adam]

You've somehow messed up the handles structure so that it is no longer a struct. It's impossible to say how or where though without seeing the rest of your code.

The fact that you are using a global variable for data doesn't bode well though if you are using them in many other places too.

[Geoff Hayes]

Bence - how are you launching your GUI? i.e. from the command line, the run button in the GUI or m-file editor, or are you opening the *.fig file (which is incorrect).

[Bence Salanki]

I am opening the *.fig file I didn't know it is incorrect. I made a new GUI with just 2 boxes and one push button to try it and I still have the same problem. I have used GUI before, but I had Matlab 2013 now I am using 2015a and before I didn't have this problem, it used to work. So here is my full code:

function varargout = proba(varargin) % PROBA MATLAB code for proba.fig % PROBA, by itself, creates a new PROBA or raises the existing % singleton*. % % H = PROBA returns the handle to a new PROBA or the handle to % the existing singleton*. % % PROBA('CALLBACK',hObject,eventData,handles,...) calls the local % function named CALLBACK in PROBA.M with the given input arguments. % % PROBA('Property','Value',...) creates a new PROBA or raises the % existing singleton*. Starting from the left, property value pairs are % applied to the GUI before proba_OpeningFcn gets called. An % unrecognized property name or invalid value makes property application % stop. All inputs are passed to proba_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 proba

% Last Modified by GUIDE v2.5 03-Apr-2017 20:23:39

% Begin initialization code - DO NOT EDIT gui_Singleton = 1; gui_State = struct('gui_Name', mfilename, ... 'gui_Singleton', gui_Singleton, ... 'gui_OpeningFcn', @proba_OpeningFcn, ... 'gui_OutputFcn', @proba_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 proba is made visible. function proba_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 proba (see VARARGIN)

% Choose default command line output for proba handles.output = hObject;

% Update handles structure guidata(hObject, handles);

% UIWAIT makes proba wait for user response (see UIRESUME) % uiwait(handles.figure1);

% --- Outputs from this function are returned to the command line. function varargout = proba_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;

function edit1_Callback(hObject, eventdata, handles1) % hObject handle to edit1 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit1 as text % str2double(get(hObject,'String')) returns contents of edit1 as a double

% --- Executes during object creation, after setting all properties. function edit1_CreateFcn(hObject, eventdata, handles1) % hObject handle to edit1 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows. % See ISPC and COMPUTER. if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor')) set(hObject,'BackgroundColor','white'); end

function edit2_Callback(hObject, eventdata, handles1) % hObject handle to edit2 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA)

% Hints: get(hObject,'String') returns contents of edit2 as text % str2double(get(hObject,'String')) returns contents of edit2 as a double

% --- Executes during object creation, after setting all properties. function edit2_CreateFcn(hObject, eventdata, handles1) % hObject handle to edit2 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles empty - handles not created until after all CreateFcns called

% Hint: edit controls usually have a white background on Windows. % See ISPC and COMPUTER. if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor')) set(hObject,'BackgroundColor','white'); end

% --- Executes on button press in pushbutton1. function pushbutton1_Callback(hObject, eventdata, handles) s = get(handles.edit1, 'String'); set(handles.edit2,'String',s); % hObject handle to pushbutton1 (see GCBO) % eventdata reserved - to be defined in a future version of MATLAB % handles structure with handles and user data (see GUIDATA)

[Bence Salanki]

Okay, if I launch GUI from the editor it works properly, thank you very much!!

Answer 1

[Geoff Hayes]

GUIDE-created GUIs can be launched from the GUI editor, the m-file editor, or from the command line by invoking the name of the GUI. Opening the figure (the *.fig) file just opens the figure and it does not perform any of the initializations that are necessary/needed for using the GUI.