Trouble with callback with uimenus
조회 수: 1 (최근 30일)
이전 댓글 표시
function startup
File = uimenu(fig,'Label','File');
Message = uimenu(File,'Label','Message','Callback',@display);
end
function display(hObj,event)
disp('Hello world')
end
When this runs through and I click on the menu I get an error saying the following:
Maximum recursion limit of 500 reached. Use set(0,'RecursionLimit',N)
to change the limit. Be aware that exceeding your available stack space can
crash MATLAB and/or your computer.
Error in CreatingMenus>display
Error while evaluating uimenu Callback
Am I missing something really obvious?
댓글 수: 0
채택된 답변
Jan
2013년 5월 28일
편집: Jan
2013년 5월 28일
Yes, you are missing something more or less obvious: When a line does not end with an semicolon, the built-in function display() is called to show the results in the command window. When you shadow the original display() function with a user-defined one, this function is called. And when it contains a line without a trailing semi-colon, it calls itself recursively.
Shadowing built-in function is a problem frequently. Therefore I'd avoid names like "display" and "startup" might lead to unexpected effects also.
Btw. you can investigate such problems by using the debugger. Set a breakpoint in the code and step through the program line by line. Then you can find out, where the recursion appears.
댓글 수: 1
Image Analyst
2013년 5월 28일
Good to know. Sometimes you don't know you've overwritten a built-in function until you have a major fecal/turbine impact. I didn't know display() was a built in function, and only sometimes do I do "which -all myFunctionName" to see if it's a built-in function. I should have noticed startup when I read his post, but I didn't - good catch on your part. He really won the exacta when he picked two reserved function names!
추가 답변 (0개)
참고 항목
카테고리
Help Center 및 File Exchange에서 Startup and Shutdown에 대해 자세히 알아보기
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!