qt moveToThread槽函数未调用

Question

或者Controller.h：

#ifndef CONTROLLER_H
#define CONTROLLER_H

#include <QObject>
#include <QThread>

class Controller : public QObject
{

    Q_OBJECT
    QThread workerThread;
public:
    Controller(QObject *parent = 0);

    ~Controller();

public slots:
    void handleResults(const QString &str);
signals:
    void operate(const QString &str);
};

#endif // CONTROLLER_H

controller.cpp：

#include "controller.h"
#include <QDebug>
#include "worker.h"

Controller::Controller(QObject *parent) : QObject(parent), workerThread()
{
    Worker *worker = new Worker;
    connect(&workerThread, &QThread::finished, worker, &QObject::deleteLater);
    connect(this, &Controller::operate, worker, &Worker::doWork, Qt::QueuedConnection);
    connect(worker, &Worker::resultReady, this, &Controller::handleResults, Qt::QueuedConnection);
    worker->moveToThread(&workerThread);
    workerThread.start();
}

Controller::~Controller()
{
    workerThread.quit();
    workerThread.wait();
}

void Controller::handleResults(const QString &str)
{
    qDebug()<<"handleResult:"<<str;
}

worker.h：

#ifndef WORKER_H
#define WORKER_H

#include <QObject>
#include <QThread>
#include <QDebug>

class Worker : public QObject
{
    Q_OBJECT
public:
public slots:
      void doWork(const QString &parameter);
signals:
      void resultReady(const QString &result);
};

#endif // WORKER_H

worker.cpp：

#include "worker.h"
#include <QDebug>

void Worker::doWork(const QString &parameter) {
    /* ... here is the expensive or blocking operation ... */

   qDebug()<<"doWork:"<<parameter;
   emit resultReady(parameter);
}

main.cpp中：

#include <QCoreApplication>
#include "worker.h"
#include <QTimer>
#include <QEvent>
#include "controller.h"


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

    Controller con;
    while(1)
    {
        QString str = "hello";
        emit con.operate(str);
        QThread::sleep(1);
    }
    return app.exec();
}

我想通过操作信号调用doWork插槽功能，在执行doWork功能之前会发出resultReady信号，但不会执行插槽函数handleResults。

函数可以调用doWork，但为什么插槽handleResults没有被调用？