QObject: Cannot create children for a parent that is in a different thread

在Qt的官方文档，大家知道有两种方式使用 QThread。

• You can use worker objects by moving them to the thread using QObject::moveToThread().
• Another way to make code run in a separate thread, is to subclass QThread and reimplement run().

在使用MoveToThread这种方式时，经常会遇到下面类似的问题：

• QObject: Cannot create children for a parent that is in a different thread.

出现这样的问题根本原因就是，调用MoveToThread 之后，在 Worker的槽函数中Worker的私有成员中又进行了new操作，并且将this指针传给了构造函数。看下实例：

mainwindow.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QThread>
#include <QMainWindow>

#include "worker.h"

namespace Ui {
class MainWindow;
}

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

signals:
    void doWorkSignal();

private:
    Ui::MainWindow *ui;