QT实现一个双向进度条窗口的代码

好的，以下是一个简单的QT程序，它实现了一个双向进度条窗口：

mainwindow.h文件：

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QMainWindow>
#include <QProgressBar>
#include <QTimer>

class MainWindow : public QMainWindow
{
    Q_OBJECT

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

private:
    QProgressBar *leftProgressBar;
    QProgressBar *rightProgressBar;
    QTimer *leftTimer;
    QTimer *rightTimer;
    int leftValue;
    int rightValue;

private slots:
    void leftTimerUpdate();
    void rightTimerUpdate();
    void startProgress();
    void stopProgress();
};

#endif // MAINWINDOW_H

mainwindow.cpp文件：

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    setFixedSize(300, 150);

    leftProgressBar = new QProgressBar(this);
    leftProgressBar->setGeometry(20, 40, 100, 20);
    leftProgressBar->setRange(0, 100);
    leftProgressBar->setValue(0);

    leftTimer = new QTimer(this);
    connect(leftTimer, SIGNAL(timeout()), this, SLOT(leftTimerUpdate()));
    leftValue = 0;

    rightProgressBar = new QProgressBar(this);
    rightProgressBar->setGeometry(180, 40, 100, 20);
    rightProgressBar->setRange(0, 100);
    rightProgressBar->setValue(100);

    rightTimer = new QTimer(this);
    connect(rightTimer, SIGNAL(timeout()), this, SLOT(rightTimerUpdate()));
    rightValue = 100;

    QPushButton *startButton = new QPushButton("Start", this);
    startButton->setGeometry(50, 90, 75, 25);
    connect(startButton, SIGNAL(clicked()), this, SLOT(startProgress()));

    QPushButton *stopButton = new QPushButton("Stop", this);
    stopButton->setGeometry(175, 90, 75, 25);
    connect(stopButton, SIGNAL(clicked()), this, SLOT(stopProgress()));
}

MainWindow::~MainWindow()
{
}

void MainWindow::leftTimerUpdate()
{
    if (leftValue == 100) {
        leftValue = 0;
    }
    leftProgressBar->setValue(leftValue++);
}

void MainWindow::rightTimerUpdate()
{
    if (rightValue == 0) {
        rightValue = 100;
    }
    rightProgressBar->setValue(rightValue--);
}

void MainWindow::startProgress()
{
    leftTimer->start(50);
    rightTimer->start(50);
}

void MainWindow::stopProgress()
{
    leftTimer->stop();
    rightTimer->stop();
}

这个程序创建了两个进度条控件，分别用于显示从左到右和从右到左的进度。每个进度条控件都有一个QTimer对象，用于在定时器超时时更新控件的值。启动和停止进度条的按钮分别连接到槽函数，用于启动和停止定时器。