求助：各位大侠，帮忙看看这小段程序有什么问题？(已解决) [复制链接]

#include <QtGui>
#include <QLabel>
#include <QPushButton>
#include <QApplication>

class Asdf : public QObject
{
    Q_OBJECT
public:
    QLabel *label;
    Asdf();
    ~Asdf();
public slots:
    void Open_Label();
};

Asdf::Asdf()
{
    label = new QLabel("Hello !");
}
Asdf::~Asdf()
{
    delete label;
}
void Asdf::Open_Label()
{
    label->show();
}

int main(int argc,char* argv[])
{
    QApplication app(argc,argv);
    QPushButton *pushButton = new QPushButton("Open");
    Asdf *asdf = new Asdf();
    Asdf::connect(pushButton,SIGNAL(clicked()),asdf,SLOT(Open_Label()));
    pushButton->show();
    return app.exec();
}

main.obj : error LNK2001: 无法解析的外部符号 "public: virtual struct QMetaObject const * __thiscall Asdf::metaObject(void)const " (?metaObject@Asdf@@UBEPBUQMetaObject@@XZ)
1>main.obj : error LNK2001: 无法解析的外部符号 "public: virtual void * __thiscall Asdf::qt_metacast(char const *)" (?qt_metacast@Asdf@@UAEPAXPBD@Z)
1>main.obj : error LNK2001: 无法解析的外部符号 "public: virtual int __thiscall Asdf::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@Asdf@@UAEHW4Call@QMetaObject@@HPAPAX@Z)
1>C:\Documents and Settings\Administrator\桌面\n\Debug\n.exe : fatal error LNK1120: 3 个无法解析的外部命令

分开写，
把该放头文件的东西放到头文件，moc时候要用到头文件。
把实现的东西放到cpp里面

Asdf::connect(pushButton,SIGNAL(clicked()),asdf,SLOT(Open_Label()));
改成 QObject::connect(pushButton,SIGNAL(clicked()),asdf,SLOT(Open_Label()));

谢谢，各位了~~~
原来这个问题是这么个情况：

Q_OBJECT不能出现在编译单元，也就是.cpp文件中

可以出现。。添加一句： #include "main.moc" 应该可以了