shixingya |
2020-01-09 18:32 |
qobject_cast转换为基类类型闹鬼事件,为什么会返回Null呢?
下面的问题原因Get了 如果既是QObject派生类,又用Q_DECLARE_INTERFACE声明为接口,用qobject_cast是会有问题的 ,用dynamic_cast 就不会有问题,如果非要用qobject_cast,则参考代码
- #undef Q_DECLARE_INTERFACE
#define Q_DECLARE_INTERFACE(IFace, IId) \ template <> inline IFace *qobject_cast<IFace *>(QObject *object) \ {IFace * face = reinterpret_cast<IFace *>((object ? object->qt_metacast(IId) : 0)); \ return face ? face : static_cast<IFace*>(reinterpret_cast<IFace*>(object)->staticMetaObject.cast(object));}
参考自 https://www.it610.com/article/4104865.htm [attachment=21240] 图中DrawToolInterface是基类,而且声明了接口类型,所以会有以上问题。
|
|