checkBoxOnTophandleA
is
null
and never becomes anything else. And when
checkBoxOnTophandleA
is
null
, then
checkBoxOnTop_CheckedChanged
calls itself, but because
checkBoxOnTophandleA
does not become anything other than
null
,
checkBoxOnTop_CheckedChanged
keeps calling itself which causes a StackOverflowException because such an Exception happens
when you have too many nested method calls[
^].