做了个实验，结论很令人困惑啊，QThread对象被delete之后居然还能用 - QTCN开发网

只看楼主倒序阅读楼主发表于: 2012-04-22

主要干了这么件事情：
让ThreadObj继承QThread，重写了run()，在run()里调用了deleteLater()
在main()里实例化了TheadObj，同时把ThreadObj的finished()信号连接至另一个槽，这个槽会调用ThreadObj的成员
听起来有点繁琐^-^
结果显示，ThreadObj的析构函数先被调用，然后那个槽才会被调用，而且槽里调用ThreadObj成员也是正确的。
这里不是有点矛盾吗？ThreadObj都被析构了，随后对其成员的调用怎么会正确呢？

代码：
main.h

复制代码

#ifndef MAIN_H
#define MAIN_H
#include <QtCore/QObject>
#include <QtCore/QThread>
#include <QtCore/QDebug>
#include <QEventLoop>
#include <QTimer>
class ThreadObj:public QThread
{
Q_OBJECT
public:
ThreadObj(QObject *parent=0):QThread(parent) {}
public slots:
void print(){ qDebug() <<"In ThreadObj::print(), current thread id is : " << currentThreadId(); }
protected:
void run(){
qDebug() << "Thread is running, current thread id is : " << currentThreadId();
QEventLoop loop;
QTimer::singleShot(2000, &loop, SLOT(quit()));
loop.exec();
deleteLater();
qDebug() << "Thread is finished";
}
public:
~ThreadObj() {
qDebug() << "delete QThread obj, current thread id is " << currentThreadId();
}
};
class Dummy:public QObject
{
Q_OBJECT
public:
Dummy(QObject* parent=0):QObject(parent) {}
public slots:
void slot() {
qDebug()<< "In dummy, current threaed id is : " << QThread::currentThreadId();
b->print();
}
public:
void set(ThreadObj *obj){ b = obj; }
private:
ThreadObj * b;
};
#endif // MAIN_H