connect

hi, why do I have this console error?? thanks

Code:

---

//my is a pointer to MainForm class
//I'm inside MyWidget constructor
connect (my->pushButton21, SIGNAL (pressed()), this, SLOT (mySlot()) );
QObject::connect: Cannot connect (null)::pressed() to MyWidget::mySlot()

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Maybe because my->pushButton21 is null?

ok. but why is it null? button21 is a button of mainform; how do I use it?

Quote:

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Originally Posted by mickey

ok. but why is it null? button21 is a button of mainform; how do I use it?

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How do you create that "my" object? Maybe you create MyWidget before you initialize button21?

hi, I don't understand qaht you want say.....the situation is this..

Code:

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MyWidget::MyWidget( QWidget *parent, const char *name, const QGLWidget* shareWidget)
        :  QGLWidget ( parent, name, shareWidget){			
	 my = (myMainForm*) this->topLevelWidget();
         connect (w->pushButton21, SIGNAL (pressed()), this, SLOT (myStartTimer()) );	
}

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Could you post myMainForm constructor?

do u want this?

Code:

---

myMainForm::myMainForm( QWidget* parent, const char* name, WFlags fl )
    : MainForm( parent, name, fl )
{
..............
}

---

Quote:

---

Originally Posted by mickey

do u want this?

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Yes, do you initialize pushButton21 there?

Quote:

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Originally Posted by jacek

Yes, do you initialize pushButton21 there?

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what do you mean? I insert butt21 from designer....

Quote:

---

Originally Posted by mickey

I insert butt21 from designer....

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In that case maybe this is wrong:

Code:

---

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

---

What happens when you use dynamic_cast?

Code:

---

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

---

a rutime error!!! and application is closed...
and without casting (my way) Q_CHECK_PTR( my ); doens't get any arror...
but my is:

Code:

---

myMainForm* my;

---

Quote:

---

Originally Posted by mickey

a rutime error!!! and application is closed...

---

This means that topLevelWidget() might return some other widget than myMainForm.

hi, using that bellow

Code:

---

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

---

it print the follow pointer

Code:

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my_mainfom in myWidget 0012E388
 mainfom this in MainForm 0012E388
 my_mainfom this in myMainForm 0012E388

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so myw in MyWidget point to mainForm.....have you any idea? thanks

if you created the window in the designer you have to call setupUi( this ); first thing in your classes constructor. Afterwards your pushbutton should exist and you can try to connect it.

Quote:

---

Originally Posted by mikro

if you created the window in the designer you have to call setupUi( this ); first thing in your classes constructor.

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He's using Qt3, there is no such thing as setupUi() there.

ooops. sorry, hadn't realized that.:o