<![CDATA[Connection failed on qchildevent after converting code from qt3 to qt4]]>Hi.

The two connects in the qchildevent function in qt4 fail, and I have no idea why.

At the top left you see the values of the variables in qt4 and at the bottom right in qt3.

The only thing I notice is unknown ‘clas’.

Can anyone help me?

Screenshot_20230520_175827.png

]]>https://forum.qt.io/topic/145251/connection-failed-on-qchildevent-after-converting-code-from-qt3-to-qt4RSS for NodeThu, 30 Apr 2026 19:29:39 GMTSat, 20 May 2023 16:34:31 GMT60<![CDATA[Reply to Connection failed on qchildevent after converting code from qt3 to qt4 on Sun, 21 May 2023 08:37:06 GMT]]>@SGaist @giusdbg I think I found and solved (if there will be no side effects), there are different event handling in qt4.

This way the added event is called while the Sensors object is still being built, and the connect fails.

Sensor::Sensor(SensorsList *parent,const char *name): QObject(parent)

In this way the added event takes place after the construction of the Sensors

Sensor::Sensor(SensorsList *parent,const char *name): QObject()
........
setParent(parent);

]]>https://forum.qt.io/post/758867https://forum.qt.io/post/758867Sun, 21 May 2023 08:37:06 GMT<![CDATA[Reply to Connection failed on qchildevent after converting code from qt3 to qt4 on Sat, 20 May 2023 20:51:31 GMT]]>@SGaist Thank you.
The one in sourceforge is my project.

The qchildevent situation is even stranger
-- In qt3 the events for inserted() are generated only after the exec() .
-- In qt4 the events for added() are all generated first, during the construction phase of the objects.

]]>https://forum.qt.io/post/758853https://forum.qt.io/post/758853Sat, 20 May 2023 20:51:31 GMT<![CDATA[Reply to Connection failed on qchildevent after converting code from qt3 to qt4 on Sat, 20 May 2023 19:05:14 GMT]]>Hi and welcome to devnet,

Someone seems to have already done the job. You might want to check this project.

]]>https://forum.qt.io/post/758848https://forum.qt.io/post/758848Sat, 20 May 2023 19:05:14 GMT