Problem with my Callback function or handles values

Hi everybody, I have a problem with my function and I do not understand why.

Here is some part of my code:

handles.STANumber = 1;
handles.PanelPosition = [60 670 1098 80];
handles.AddSTA = uicontrol( 'Parent',handles.MainFigure,...
                              'style','pushbutton',...
                              'String','Add STA',...
                              'Tag','AddSTA',...
                              'Callback', {@AddSTA,handles});
handles.STANumber = handles.STANumber + 1;

....
function [handles] = AddSTA(hObject,eventdata,handles)
handles.AddSTA = hObject; % I DO NOT KNOW WHY THIS IS NEEDED. without this
                          % handles.AddSTA is not recognized - but all the
                          % other handles are recognized
handles.STANumber = handles.STANumber + 1;

My main problems are:

1. When I enter the AddSTA function the handles structure does not have AddSTA field

2. Every time I enter the AddSTA function - handles.STANumber is '1' (even though I prev' increased it) - On the same not - handles.PanelPosition is also in his default value.

Answer 1

[Brian B]

You need to save handles back to the figure after each call, as in:

handles.STANumber = handles.STAumber + 1;
guidata(hObject,handles);

See http://www.mathworks.com/help/matlab/ref/guidata.html.

[Nimrodb]

I tried that already. I places 1 in my main function (at the end) and got the folloiwng error:

Reference to a cleared variable hObject.

Error in SimulationMain (line 28)
guidata(hObject,handles);

and I also tried to place 1 at the end of the AddSTA function and that did not produce an error - but also did not do anything.

[Walter Roberson]

Do you have "clear all" statements in your code?