如何使 QTimer 工作

项目结构如下：
device.h

#ifndef DEVICE_H
#define DEVICE_H

#include <QWidget>
class device : public QWidget
{
    Q_OBJECT
signals:
    void takeMidVal(int midVal);
public:
    device(QWidget *parent = nullptr);
public slots:
    void seek(int bin);

};

#endif // DEVICE_H

设备.cpp

#include "device.h"

device::device(QWidget *parent) :
    QWidget(parent)
{

}
void device::seek(int bin)
{
    int midVal = 800;
    emit(takeMidVal(midVal));
}

对话框.h

#ifndef DIALOG_H
#define DIALOG_H
#include <QApplication>
#include <QDialog>
#include <QPushButton>
#include <QVBoxLayout>
#include <math.h>
#include <windows.h>
#define ACCEPT_DIFF         100
#define SIZE_OF_SAMPLE      10
#define SIZE_OF_NOISE       10

#define MK_SILENCE             -2
#define MK_INCORRECT_RESPONSE  -1
#define MK_WAITING              0
#define MK_CORRECT_RESPONSE     1

class Dialog : public QDialog
{
    Q_OBJECT
signals:
    void sendCommand();
    void setBinToSeek(int bin);
public:
    int configRes;
    int result;
    int midCount;
    int midValue;
    bool waitFlag;
    QPushButton* btn;
    explicit Dialog(QWidget *parent = nullptr);
    ~Dialog();
public slots:
    void computeMid(int curVal);
private slots:
    void handleClick();


};

#endif // DIALOG_H

对话框.cpp

#include "dialog.h"

Dialog::Dialog(QWidget *parent) :
    QDialog(parent)
{
    QVBoxLayout *mainLayout = new QVBoxLayout;
    btn = new QPushButton();
    mainLayout->addWidget(btn);
    this->setLayout(mainLayout);
    connect(btn,SIGNAL(clicked()),this,SLOT(handleClick()));
}
void Dialog::handleClick()
{
    result = -1;
    int amplitude = 1000;
    int bin = 10;
    unsigned char min = 1;
    unsigned char max =static_cast<unsigned char>(255);
    unsigned char command = 0;
    bool success = false;
    while(max-min > 1)
    {
        command = (min + (max-min)/2);
        configRes = MK_WAITING;
        emit(sendCommand());
        while(configRes == MK_WAITING)
        {
            QApplication::instance()->processEvents();
            Sleep(100);
        }
        emit(setBinToSeek(bin));
        waitFlag = true;
        midCount = 0;
        midValue = 0;
        int sleepCount = 0;
        while(waitFlag)
        {
            if(sleepCount >= 50)
            {
                return;
            }
            QApplication::instance()->processEvents();
            Sleep(300); //wait untill get mid value of pick in other thread
            ++sleepCount;
        }
        int diff = amplitude - midValue;
        if(diff < 0)
        {
            if(-diff < ACCEPT_DIFF)
            {
                success = true;
                break;
            }
            else
            {
                min = static_cast<unsigned char>(command);
            }
        }
        else
        {
            if(diff < ACCEPT_DIFF)
            {
                success = true;
                break;
            }
            else
            {
                max = static_cast<unsigned char>(command);
            }
        }
    }
    if(success)
    {
        result = static_cast<int>(command);
        return;
    }
}

void Dialog::computeMid(int curVal)
{
    midValue += curVal;
    ++midCount;
    if(midCount >= SIZE_OF_SAMPLE)
    {
        midValue /= midCount;
        waitFlag = false;
    }
}
Dialog::~Dialog()
{
}

主窗口.h

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QTimer>
#include "dialog.h"
#include "device.h"
class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    QPushButton* btn;
    QTimer timer;
    Dialog* d;
    device* dev;
    explicit MainWindow(QWidget *parent = nullptr);
    ~MainWindow();

private slots:
    void createDialog();
    void handleTimeOut();
    void sendCommand();
};

#endif // MAINWINDOW_H

主窗口.cpp：

#include "mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent)
{
    dev = new device(this);
    btn = new QPushButton();
    this->layout()->addWidget(btn);
    connect(btn,SIGNAL(clicked()),this,SLOT(createDialog()));
    connect(&timer,SIGNAL(timeout()),this,SLOT(handleTimeOut()));
}

void MainWindow::sendCommand()
{
    timer.start(5000);
}
void MainWindow::createDialog()
{
    d = new Dialog();
    connect(d,SIGNAL(sendCommand()),this,SLOT(sendCommand()));
    connect(dev,SIGNAL(takeMidVal(int)),d,SLOT(computeMid(int)));
    connect(d,SIGNAL(setBinToSeek(int)),dev,SLOT(seek(int)));
    d->exec();
}
void MainWindow::handleTimeOut()
{
    d->configRes = MK_CORRECT_RESPONSE;
}
MainWindow::~MainWindow()
{
}

主文件

#include <QApplication>
#include <QtCore>
#include <QtGui>
#include "mainwindow.h"
int main(int argc, char *argv[])
{

    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}

示例项目本身
当我发送信号时，调用了 sendCommand 插槽，这没有问题。但是从槽返回后，当定时器到期时，处理程序不会被调用。计时器完成后如何跳转到处理程序？

如果我们从一个抽象的例子转移到一个真实的例子，那么会发生以下情况：从主窗口调用一个模式。在模态窗口执行代码期间，会向主机发送信号，以通过 COM 端口向设备发送命令。此外，有必要从设备接收响应并处理它的缺失或不正确。为此，使用了计时器。
据我了解，发出信号后，模态窗口代码的执行一刻也没有停过，于是我就把它无限循环，直到flag落下，表示所​​有处理完成。
但问题是定时器并没有以任何方式触发handler调用，退出slot后什么也没有发生，模态窗口代码的执行就陷入了死循环。

已添加以下内容。通过调用handleClick，生成一个命令，发送到device1，影响device2的输出。之后，向 device2 发送一个信号，以便它开始返回某个值。当收集到足够数量的这些值时，会计算它们的算术平均值，并估计接收到的值与期望值之间的差异。如果差值大于最小值，则球队的阵型会有调整，一切都重新开始。