使用Qt编程。界⾯上有⼀个⽂本显示框 QLabel，计算 2 到 50 的斐波那契数列结果，每次计算完成后，将计算结果显示在 QLabel上。 要求： 计算过程中界⾯不能卡顿； 程序关闭时⽴即退出，并且不会出现崩溃； 分别使⽤QThread和moveToThread两种⽅式实现。

使用QThread实现：

// fibthread.h
#ifndef FIBTHREAD_H
#define FIBTHREAD_H

#include <QThread>

class FibThread : public QThread {
    Q_OBJECT
public:
    explicit FibThread(QObject *parent = nullptr);

signals:
    void result(int);

protected:
    void run() override;
};

#endif // FIBTHREAD_H

// fibthread.cpp
#include "fibthread.h"

FibThread::FibThread(QObject *parent) : QThread(parent) {}

void FibThread::run() {
    int fib1 = 0, fib2 = 1;
    for (int i = 2; i <= 50; ++i) {
        int fib = fib1 + fib2;
        fib1 = fib2;
        fib2 = fib;
        emit result(fib);
    }
}

// mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QThread>

namespace Ui {
class MainWindow;
}

class FibThread;

class MainWindow : public QMainWindow {
    Q_OBJECT

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

private slots:
    void onCalculateFinished(int fib);

private:
    Ui::MainWindow *ui;
    FibThread *fibThread;
};

#endif // MAINWINDOW_H

// mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "fibthread.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow),
    fibThread(new FibThread(this))
{
    ui->setupUi(this);

    connect(fibThread, &FibThread::result, this, &MainWindow::onCalculateFinished);
    fibThread->start();
}

MainWindow::~MainWindow()
{
    delete ui;
    fibThread->quit();
    fibThread->wait();
}

void MainWindow::onCalculateFinished(int fib) {
    ui->label->setText(QString::number(fib));
}

使用moveToThread实现：

// fibworker.h
#ifndef FIBWORKER_H
#define FIBWORKER_H

#include <QObject>
#include <QThread>

class FibWorker : public QObject {
    Q_OBJECT
public:
    explicit FibWorker(QObject *parent = nullptr);

public slots:
    void calculate();

signals:
    void result(int);
};

#endif // FIBWORKER_H

// fibworker.cpp
#include "fibworker.h"

FibWorker::FibWorker(QObject *parent) : QObject(parent) {}

void FibWorker::calculate() {
    int fib1 = 0, fib2 = 1;
    for (int i = 2; i <= 50; ++i) {
        int fib = fib1 + fib2;
        fib1 = fib2;
        fib2 = fib;
        emit result(fib);
    }
}

// mainwindow.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QThread>

namespace Ui {
class MainWindow;
}

class FibWorker;

class MainWindow : public QMainWindow {
    Q_OBJECT

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

private slots:
    void onCalculateFinished(int fib);

private:
    Ui::MainWindow *ui;
    QThread *workerThread;
    FibWorker *fibWorker;
};

#endif // MAINWINDOW_H

// mainwindow.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
#include "fibworker.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow),
    workerThread(new QThread(this)),
    fibWorker(new FibWorker)
{
    ui->setupUi(this);

    fibWorker->moveToThread(workerThread);
    connect(workerThread, &QThread::finished, fibWorker, &QObject::deleteLater);
    connect(this, &MainWindow::destroyed, workerThread, &QThread::quit);
    connect(fibWorker, &FibWorker::result, this, &MainWindow::onCalculateFinished);
    connect(this, &MainWindow::destroyed, fibWorker, &FibWorker::deleteLater);

    workerThread->start();
    QMetaObject::invokeMethod(fibWorker, "calculate", Qt::QueuedConnection);
}

MainWindow::~MainWindow()
{
    delete ui;
    workerThread->quit();
    workerThread->wait();
}

void MainWindow::onCalculateFinished(int fib) {
    ui->label->setText(QString::number(fib));
}