未解析的外部符号“public: virtual struct QMetaObject const * __thiscall Parent

I inherited a class from QObject :

class Parent: public QObject
{
    Q_OBJECT
    QObject* cl;

public:
    Parent(QObject *parent=0):QObject(parent) {
        cl = NULL;
    }

    QObject* getCl() const {
        return cl;
    }
    void setCl(QObject *obj) {
        cl = obj;
    }
};

但是当我写:

Parent ev;

我收到以下错误:

main.obj:-1: error: LNK2001: unresolved external symbol "public: virtual struct QMetaObject const * __thiscall Parent::metaObject(void)const " (?metaObject@Parent@@UBEPBUQMetaObject@@XZ)

main.obj:-1: error: LNK2001: unresolved external symbol "public: virtual void * __thiscall Parent::qt_metacast(char const *)" (?qt_metacast@Parent@@UAEPAXPBD@Z)

main.obj:-1: error: LNK2001: unresolved external symbol "public: virtual int __thiscall Parent::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@Parent@@UAEHW4Call@QMetaObject@@HPAPAX@Z)

推荐答案

您应该删除应用程序的 debug 文件夹，然后再次运行以解决此问题.