findobj does not work

When the gui main program is running, I use findobj('Name', 'Gui_Main_Program');

This command does not work in timer callback function. It neither work in Matlab command window.

I see everyone says do not use global variables, so I put data in gui_main_hObject.UserData.

Thank you.

[Star Strider]

The first argument to findobj must the the handle to the object you want to use it with.

[Walter Roberson]

No, https://www.mathworks.com/help/matlab/ref/findobj.html shows multiple syntaxes in which there is no object passed

Answer 1

[Walter Roberson]

Either there is no object with exactly that name, or else the handle of it is not visible.

What shows up for

get(findall('type', 'figure'), 'Name')

[Rocky Zhang]

It shows

Invalid handles passed to findall.

Where do I get or set whether the handle is visible?

I solved my problem by using a global variable.

[Walter Roberson]

get(findall(0, 'type', 'figure'), 'Name')

I keep forgetting that findall requires a first parameter

[Rocky Zhang]

This one works.

Thank you Walter!