QT制作一个汽车仪表盘-QT开发中文网

以下是一个简单的汽车仪表盘的QT代码示例：

main.cpp文件：

#include <QApplication>
#include "dashboard.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Dashboard w;
    w.show();
    return a.exec();
}

dashboard.h文件：

#ifndef DASHBOARD_H
#define DASHBOARD_H

#include <QWidget>
#include <QTimer>

class Dashboard : public QWidget
{
    Q_OBJECT

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

private:
    QTimer *m_timer;
    int m_speed;

protected:
    void paintEvent(QPaintEvent *event) override;
};

#endif // DASHBOARD_H

dashboard.cpp文件：

#include "dashboard.h"
#include <QPainter>

Dashboard::Dashboard(QWidget *parent)
    : QWidget(parent), m_speed(0)
{
    setFixedSize(300, 300);

    m_timer = new QTimer(this);
    connect(m_timer, &QTimer::timeout, [this](){
        m_speed += 10;
        if (m_speed > 240) {
            m_speed = 0;
        }
        update();
    });
    m_timer->start(1000);
}

Dashboard::~Dashboard()
{
}

void Dashboard::paintEvent(QPaintEvent *event)
{
    Q_UNUSED(event);

    static const QPoint points[] = {
        QPoint(150, 70),
        QPoint(170, 70),
        QPoint(170, 90),
        QPoint(150, 90)
    };
    static const int speedLabelRadius = 60;
    static const int speedNeedleRadius = 50;
    static const int speedArcRadius = 80;
    static const int scaleLength = 10;
    static const int gaugeWidth = 4;

    QPainter painter(this);
    painter.setRenderHint(QPainter::Antialiasing);

    // 画表盘
    painter.save();
    painter.translate(width() / 2, height() / 2);

    QPen pen;
    pen.setWidth(gaugeWidth);
    painter.setPen(pen);

    // 画速度表刻度
    for (int i = 0; i <= 240; i += 20) {
        if (i % 60 == 0) {
            painter.drawLine(speedArcRadius - scaleLength, 0, speedArcRadius, 0);
        } else {
            painter.drawLine(speedArcRadius - scaleLength / 2, 0, speedArcRadius, 0);
        }
        painter.rotate(1.5);
    }

    // 画速度表指针
    painter.rotate(-120 + m_speed * 1.5);
    painter.drawLine(0, 0, speedNeedleRadius, 0);

    // 画速度表数字
    pen.setWidth(2);
    painter.setPen(pen);
    QFont font;
    font.setPointSize(14);
    painter.setFont(font);
    QRectF speedLabelRect(-speedLabelRadius, -speedLabelRadius, speedLabelRadius * 2, speedLabelRadius * 2);
    painter.drawText(speedLabelRect, Qt::AlignCenter, QString::number(m_speed));
    painter.restore();
}

上述代码实现了一个简单的汽车仪表盘，包括了速度表盘、刻度、指针和数字。可以在QT中运行，并且每秒钟更新一次速度值，使指针动态移动。但这只是一个简单的示例，实际情况下可能需要更复杂的汽车仪表盘，需要根据实际需求进行开发。