qt错误:未定义对"vtable for Thread"的引用 [英] qt error: undefined reference to `vtable for Thread'

问题描述

我有代码:

#include <iostream>
#include <QThread>
#include <unistd.h>
#include <stdlib.h>
#include <QApplication>


using std::cerr;
using std::endl;

class Thread : public QThread
{
    Q_OBJECT
public:
    Thread();
    ~Thread();
    void setMessage(const QString &_message);
    void stop();
protected:
    void run();
private:
    QString message;
    volatile bool stopped;
};

Thread::Thread()
{
    stopped = false;    
    run();
}

Thread::~Thread()
{

}


void Thread::run()
{
    while(!stopped){
        cerr << qPrintable(message);
        sleep(1);
    }
        stopped = false;
        cerr << endl;
}

void Thread::stop()
{
    stopped = true; 
}

void Thread::setMessage(const QString &_message)
{
    message = _message; 
}

int main(int argc,char *argv[])
{
    QApplication app(argc, argv);
    Thread *A,*B;
    A = new Thread();
    B = new Thread();
    A->setMessage("Thread A\n");
    B->setMessage("Thread B\n");
//.run();
//.run();
    sleep(10);
    A->stop();
    B->stop();
    return 0;
}

我有错误

g++ -Wl,--hash-style=gnu -Wl,--as-needed -Wl,-O1 -o tmp main.o    -L/usr/lib -lQtGui -lQtCore -lpthread 
main.o: In function `Thread::~Thread()':
main.cpp:(.text+0xa): undefined reference to `vtable for Thread'
main.o: In function `Thread::Thread()':
main.cpp:(.text+0x1da): undefined reference to `vtable for Thread'
collect2: ld returned 1 exit status
make: *** [tmp] Error 1

推荐答案

您必须使用moc生成标头.这可以通过Qt构建系统自动完成.而不是直接使用gcc，您应该使用qmake文件.

You must generate a header with moc. This can be done automatically with the Qt build system. Instead of using gcc directly, you should use a qmake file.

另外，您可能应该将声明和代码分为头文件和cpp文件.

Also you should probably separate the declaration and code into header file and cpp file.

以下是moc所做的描述: http://doc.qt.nokia.com/latest/moc.html

Here is a description of what moc does: http://doc.qt.nokia.com/latest/moc.html

还有一个关于stackoverflow的类似问题(带有答案):对vtable的未定义引用.尝试编译Qt项目

And a similar question (with answers) here on stackoverflow: Undefined reference to vtable. Trying to compile a Qt project

这篇关于qt错误:未定义对"vtable for Thread"的引用的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！