Object::connect:no such slot (loss of QT slot)

1. See if you have q_object in your class declaration and inherit the public qmainwindow{

For example:

Class Cplot:public qmainwindow{
	q_object

2, you declare the function to add the declaration:

Private Slots:

void xxxx ();

And you want to add the function above to the constructor, which is accessed directly by the constructor:

Public:
    Cplot (Qwidget *parent = 0);
    Private slots:
        void OpenFile ();
        void Segmentobj ();
        void Capture ();
        void Drawrays ();   

3, check the slot function name spelling is incorrect, and the corresponding signal and slot parameters are consistent

If not, clean up the project, delete the original moc_xxx.cpp, and perform qmake again.

or modify it yourself:

For example: adding slots:

static const char qt_meta_stringdata_openglviewer[] = {
	"mainviewer\0\0openfile () \0segmentobj ()"
	"capture () ""
};

void Cplot::qt_static_metacall (QObject *_o, qmetaobject::call _c, int _id, void **_a)
{
	if (_c = = Qmetaobject::in Vokemetamethod) {
		Q_assert (Staticmetaobject.cast (_o));
		Cplot *_t = Static_cast<cplot *> (_o);
		Switch (_id) {case
		0: _t->openfile ();
		Case 1: _t->segmentobj (); break;
		Case 2: _t->capture (); break;
		Default:;
		}
	}
	Q_unused (_a);
}