On Thursday 20 January 2005 23:48, Mohsen Pahlevanzadeh wrote: > It mean that i must derive a class from KTMainwindow? No. ClassName x = ClassName(); invokes the copy constructor of class name when initializing x. QObject subclasses like QWidget or KMainWindow cannot be copied, their copy constructor is private, thus the compiler error. Either create the instance on the heap or initialize the instance directly ClassName* x = new ClassName(parameters); or ClassName x(parameters); Btw, the example looks like KDE1 code, are you sure you are developing for that version? Moreover development question are better suited for kde-devel :) Cheers, Kevin -- Kevin Krammer <kevin.krammer@xxxxxx> Qt/KDE Developer, Debian User www.mrunix.de - German Unix/Linux programming forum www.qtforum.org - Qt programming forum ___________________________________________________ . Account management: https://mail.kde.org/mailman/listinfo/kde. Archives: http://lists.kde.org/. More info: http://www.kde.org/faq.html.