simple question:the slot and signal of QTreeWidget

[weixj2003ld]

I create a class as follows:

class CTreeClass:public QTreeWidget
{
public:
      CTreeClass(QWidget *parent);
public slots:
     void showMessage(QTreeWidgetItem *item, int index);
};

class CTreeClass:public QTreeWidget
{
public:
      CTreeClass(QWidget *parent);
public slots:
     void showMessage(QTreeWidgetItem *item, int index);
};

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and in the function CTreeClass,the part of code as follows:

CTreeClass::CTreeClass(QWidget *parent)
:QTreeWidget(parent)
{
...
QObject::connect(this,SIGNAL(itemClicked(QTreeWidgetItem *, int)),this,SLOT(showMessage(QTreeWidgetItem *, int)));
....
}

CTreeClass::CTreeClass(QWidget *parent)
:QTreeWidget(parent)
{
...
QObject::connect(this,SIGNAL(itemClicked(QTreeWidgetItem *, int)),this,SLOT(showMessage(QTreeWidgetItem *, int)));
....
}

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The function showMessage is only show a message(as a test),but when I click the item of the tree,nothing does,Why?

[caduel]

you forgot the Q_OBJECT macro in your class (whenever you declare a signal or slot, you need this macro in the class)

[weixj2003ld]

Thanks a lot.
But if I add the Q_OBJECT to my program,and compile it,the errors occur:

cprojecttree.obj : error LNK2001: unresolved external symbol  "public: virtual struct QMetaObject const * __thiscall CTreeClass::metaObject(void)const " (?metaObject@CTreeClass@@UBEPBUQMetaObject@@XZ)
cprojecttree.obj : error LNK2001: unresolved external symbol  "public: virtual void * __thiscall CTreeClass::qt_metacast(char const *)" (?qt_metacast@CTreeClass@@UAEPAXPBD@Z)
cprojecttree.obj : error LNK2001: unresolved external symbol  "public: virtual int __thiscall CTreeClass::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CTreeClass@@UAEHW4Call@QMetaObject@@HPAPAX@Z)

cprojecttree.obj : error LNK2001: unresolved external symbol  "public: virtual struct QMetaObject const * __thiscall CTreeClass::metaObject(void)const " (?metaObject@CTreeClass@@UBEPBUQMetaObject@@XZ)
cprojecttree.obj : error LNK2001: unresolved external symbol  "public: virtual void * __thiscall CTreeClass::qt_metacast(char const *)" (?qt_metacast@CTreeClass@@UAEPAXPBD@Z)
cprojecttree.obj : error LNK2001: unresolved external symbol  "public: virtual int __thiscall CTreeClass::qt_metacall(enum QMetaObject::Call,int,void * *)" (?qt_metacall@CTreeClass@@UAEHW4Call@QMetaObject@@HPAPAX@Z)

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[aamer4yu]

Try rebuilding the project ...
from step to making project file...(qmake -tp vc :::in windows)