Hi everyone,

I'm new to this forum as to C++ and now Qt. Currently I'm studying this tutorial http://doc.qt.nokia.com/4.4/tutorials-tutorial-t8.html . I hope that some of you are familiar with it?

CODE IN TUTORIAL
~~~~~~~~~~~~~~~~~~~~~~~
In the tutorial they do several connects. I believe those are relevant atm:
  • In lcdrange.cpp:
    Qt Code: 
    1. connect(slider, SIGNAL(valueChanged(int)), this, SIGNAL(valueChanged(int)));
    To copy to clipboard, switch view to plain text mode 
  • In main.cpp
    Qt Code: 
    1. LCDRange *angle = new LCDRange;
    2. connect(angle, SIGNAL(valueChanged(int)), cannonField, SLOT(setAngle(int)));
    To copy to clipboard, switch view to plain text mode 


So, they connect slider.valueChanged(int) with the slot cannonField.setAngle(int) "via" the signal angle.valueChanged(int).


PROBLEM
~~~~~~~~~~~~~~~~~~~~~~~~~~~
I tried to connect them directly. In main.cpp I added the line
Qt Code: 
  1. connect(angle->slider, SIGNAL(valueChanged(int)), cannonField, SLOT(setAngle(int)));
To copy to clipboard, switch view to plain text mode 

(I also turned the QSlider * slider public in lcdrange.h)

But then the build problem occurs "cannot convert parameter 1 from 'QSlider *' to 'const QObject *' Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast". I don't really understand the problem. In my view, they were connected already before, just indirect.

I would be grateful if anybody could explain it to me, thanks!