Calling a class method from a GUI
显示 更早的评论
Hello there?
I am making a OOP test program that we can run at a GUI. The code for the class is
classdef test_1 < handle
properties
name
connectStatus = 0
end
methods
% Constructor
function obj = test_1(test_name)
obj.name = test_name
end
function status = getStatus(obj)
status = obj.connectStatus
end
function obj = setStatus(obj, newStatus)
obj.connectStatus = newStatus
end
end
end
When I run this on workspace, I found that it works fine. I can check the values of the attributes of the object and I can run the method suich as getStatus, setStatus.
Now I made a GUI and tried to run the method whenever I push a button on the GUI. But Matlab gives me error messages like
'Undefined variable "obj" or class "obj.getStatus"'.
Here, obj is the object that I created and getStatus is the method.
I think the problem is simple but I do not know how to solve this.
So, I will be very thankful if someone give me a tip.
Thanks.
1 个评论
snow John
2019-9-2
Hello sir，
I have met the same problem ，can you give me some cases as reference.
Your help will be appreciated.
Bset!
-John
采纳的回答
Geoff Hayes
2015-3-29
Wooshik - I suspect that what is happening is that you have defined your obj object either in the base workspace (outside of the GUI) or you have created it as a local variable in one callback or the Opening Function of your GUI and are trying to reference it in the push button callback. If either is the case, then the error message makes sense since obj is not part of the function workspace (see http://www.mathworks.com/help/matlab/matlab_prog/base-and-function-workspaces.html for an explanation of the workspaces).
If you want to reference the obj across callback within your GUI, and assuming that you have used GUIDE to create the GUI, then use the handles object to store this data. For example, if you create obj in the Opening Function as
function myGui_OpeningFcn(hObject, eventdata, handles, varargin)
% Choose default command line output for untitled
handles.output = hObject;
% create the obj object
obj = test_1('Any name');
% save obj as a field within handles
handles.obj = obj;
% Update handles structure
guidata(hObject, handles);
The order in the above is important - we create the object obj, save it as a field of handles, and then update the handles structure with guidata so that all other callback will have the updated version of handles.
Now in your push button callback you would do something like
function pushbutton1_Callback(hObject, eventdata, handles)
if isfield(handles,'obj')
myObj = handles.obj;
myObj.getStatus;
end
In the above, we are checking to see if the obj field exists within handles before trying to access it.
Try the above and see what happens!
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Loops and Conditional Statements 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
