connect

[jacek]

I insert butt21 from designer....

In that case maybe this is wrong:

my = (myMainForm*) this->topLevelWidget();

my = (myMainForm*) this->topLevelWidget();

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What happens when you use dynamic_cast?

my = dynamic_cast< myMainForm*>( topLevelWidget() );
Q_CHECK_PTR( my );

my = dynamic_cast< myMainForm*>( topLevelWidget() );
Q_CHECK_PTR( my );

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