No Such Slot

[anda_skoa]

ars already explained the situation and its solutions but just to be more precise: your error message are actually two error messages.

The first line is from the "connected by name" feature and complains that there is no signal with the name "valuechanged" on object sizeslider, because it only has "valueChanged" (capitalization error).

The second and third line are from the connect() statement, since you had "int value" in your SLOT macro, but it only expects argument types, so just "int".

And of course I also fully agree with ars' assessment regarding using "connect by name". I.e. I would also always use and recommend explicit connect.

Cheers,
_