编译器错误“collect2: Id returned 1 exit status”将类与 QObject 一起使用（带有 Qt Creator 的 QT 4.7）

Question

我当前的项目中出现以下情况：编译器使用以下代码返回“collect2: Id returned 1 exit status”：

#ifndef BASE_02_H
#define BASE_02_H

#include <QtCore>

class Base_02
{

public:
    Base_02();

    virtual void method()=0;
};

#endif // BASE_02_H

#include "base_02.h"
#include <QtCore>

Base_02::Base_02()
{

}

//----------------------------------------------------------------------------------------------------------------------------------

#ifndef DERIVED_02_H
#define DERIVED_02_H

#include <QtCore>
#include "base_02.h"

class Derived_02 : public Base_02
{

public:
    Derived_02();
    void method();
};

#endif // DERIVED_02_H

#include "derived_02.h"
#include <QtCore>

Derived_02::Derived_02()
{

}

void Derived_02::method()
{
    qDebug() << "Derived_02::method()";
}

//----------------------------------------------------------------------------------------------------------------------------------

#ifndef BASE_H
#define BASE_H

#include <QtCore>

class Base : public QObject
{
    Q_OBJECT

public:
    Base(Base* p=NULL);

    virtual void method()=0;
};

#endif // BASE_H

#include "base.h"
#include <QtCore>

Base::Base(Base* p)
{

}

//----------------------------------------------------------------------------------------------------------------------------------

#ifndef DERIVED_H
#define DERIVED_H

#include <QtCore>
#include "base.h"

class Derived : public Base
{
    Q_OBJECT

public:
    Derived(Derived* p=NULL);
    void method();
};

#endif // DERIVED_H

#include "derived.h"
#include "derived_02.h"
#include <QtCore>

Derived::Derived(Derived* p)
{

}

void Derived::method()
{
    Derived_02 d;
    d.method();
}

//----------------------------------------------------------------------------------------------------------------------------------

#include <QtCore/QCoreApplication>
#include <QtCore>
#include "base.h"
#include "derived.h"

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);



    Derived* derived = new Derived();



    return a.exec();
}

编译器显示以下内容：

... mingw32-make：进入目录 C:/Entwicklung SVN/debug test/dataSenderReceiverExample' C:/Qt/2010.04/mingw/bin/mingw32-make -f Makefile.Debug mingw32-make[1]：进入目录C:/Entwicklung SVN/debug test/dataSenderReceiverExample' g++ -c -g -frtti -fexceptions -mthreads -Wall -DUNICODE -DQT_LARGEFILE_SUPPORT -DQT_DLL -DQT_CORE_LIB -DQT_THREAD_SUPPORT -I"......\Qt\2010.04\qt\include\QtCore" -I".... ..\Qt\2010.04\qt\include" -I"..\dataSenderReceiver" -I"......\Qt\2010.04\qt\include\ActiveQt" -I"调试" -I"... ...\Qt\2010.04\qt\mkspecs\win32-g++" -o debug\main.o main.cpp main.cpp：在函数“int main(int, char**)”中： main.cpp：14：警告：未使用的变量“派生” g++ -enable-stdcall-fixup -Wl,-enable-auto-import -Wl,-enable-runtime-pseudo-reloc -Wl,-subsystem,console -mthreads -Wl -o debug\dataSenderReceiverExample.exe debug/main.o -L"c:\Qt\2010.04\qt\lib" -L../dataSenderReceiver/debug -ldataSenderReceiver -lQtCored4 mingw32-make[1]：离开目录 C:/Entwicklung SVN/debug test/dataSenderReceiverExample' mingw32-make：离开目录C:/Entwicklung SVN/debug test/dataSenderReceiverExample' ../dataSenderReceiver/debug/libdataSenderReceiver.a(衍生.o):C:\Entwicklung SVN\debug test\dataSenderReceiver/衍生.cpp:14: 未定义引用 Derived_02::Derived_02()' ../dataSenderReceiver/debug/libdataSenderReceiver.a(衍生.o):C:\Entwicklung SVN\debug test\dataSenderReceiver/衍生.cpp:15: 未定义引用Derived_02::method()' Collect2: ld 返回 1 退出状态 mingw32-make[1]: * [debug\dataSenderReceiverExample.exe] 错误 1 mingw32-make: * [调试] 错误 2 Prozess“C:/Qt/2010.04/mingw/bin/mingw32-make.exe”将在 Rückgabewert %2 中运行。 Fehler beim Erstellen des Projekts dataSenderReceiverExample（Ziel：桌面） Beim Ausführen des Build-Schritts 'Make'

请帮忙！

Answer 1

#include "base_02.h"
#include <QtCore>

必须是：

#include <QtCore>
#include "base_02.h"

然后它就可以编译了！

Answer 2

我在以下情况下遇到了这个问题：

---

说

A 是一个可执行（fi 控制台）项目并且
B 和 C 是库（fi static lib）项目并且
A 使用 B，B 使用 C。

那么

A 必须通过 .pro 文件了解 B 库和 C 库，并且
B 必须通过 .pro 文件了解 C 库。

---

假设

在 A .pro 文件中，库 C 在库 B 之前表示：

LIBS *= -L"../C/debug"
LIBS *= -lC
INCLUDEPATH *= "../C"

LIBS *= -L"../B/debug"
LIBS *= -lB
INCLUDEPATH *= "../B"

那么

就会出现上述错误。

---

解决方案：

在 A .pro 文件中将库 B 命名在库 C 之前：

LIBS *= -L"../B/debug"
LIBS *= -lB
INCLUDEPATH *= "../B"

LIBS *= -L"../C/debug"
LIBS *= -lC
INCLUDEPATH *= "../C"

Answer 3

I got same problem here...??
#include<iostream>
using namespace std;
class employee{
    protected:
        int id; 
        string name;
        int day;
        int salary;
    public:
        virtual void calsalary()=0;
};
class facultyemp:public employee{
    public:
        static int k;
        facultyemp(){
            k++;
            id=k;
        }
        void setname(){
            cout<<"Enter name:";
            cin>>name;
        }
        void setday(){
            cout<<"Enter worked days:";
            cin>>day;
        }
        void setsalary(){
            cout<<"Enter salary pr day:";
            cin>>salary;
        }
        void getname(){
            cout<<"Name: "<<name;
        }
        void getid(){
            cout<<"\nID: "<<id;
        }
        void calsalary(){
            cout<<"The net salary: ";
            cout<<day*salary;
        }

};
static int k=0;
int main(){
    employee *e;
    facultyemp f;
    e=&f;
    f.setname();
    f.setday();
    f.setsalary();
    f.getname();
    f.getid();
    e->calsalary();

}