C++ (Qt)F=@Variant(\0\0\0?A\x1e\x66\x66)
C++ (Qt)float F;...F= ui->lineEdit->text().toFloat();....settings.setValue("F",F);
C++ (Qt)QString F;...F= ui->lineEdit->text().toString();....settings.setValue("F",F);
settings.setValue("F",QString::number(F, 'f', 6));
F = settings.value("F").toFloat();
C++ (Qt)settings.setValue("F",QLocale::c().toString(F, 'f', 6));
C++ (Qt)F = QLocale::c().toFloat(settings.value("F").toString());
C++ (Qt)QChar QLocale::decimalPoint () const