Build error when subclassing of subclassing from QObject
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build error is happen when subclassing of subclassing from QObject.
is there any solution to avoid this problem?
this is source code & error
!http://crazygun22.g3.cc/ee.png(source code & error)!
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this is my qt version
Qt Creator 3.3.0 (opensource)
Based on Qt 5.4.0 (MSVC 2010, 32 bit)Built on Dec 8 2014 at 15:24:21
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Do you need Q_OBJECT in 'sub' class ? This is the source of your error.
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i need to send signal in both base and sub classes,
so i wrote the Q_OBJECT in both class.if writing Q_OBJECT in both class is impossible, how can i send signal in both classes?
build error is also happen when writing emit function to send signal without Q_OBJECT in Sub class
-------------------------------Sub.h------------------------------------
class Sub : public Base
{
.......
signals:
void sendSigKey(const QString &key) const;
};-------------------------------Sub.c---------------
void Sub::send()
{
emit sendSigKey("asdf");
}
--------------------------------Error------------
error: undefined reference to `Sub::sendSigKey(QString const&) const' -
Did you do a clean qmake ?
Delete your build folder
Run qmake
Build your project.After that i think you have to remove the const qualifier in your constructor !
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Hi,
To add to my fellow, when adding/removing the Q_OBJECT macro you need to run qmake once to update the build part. Then it should build cleanly
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thank you, SGaist
your reply sloved my problem.