用Qt写一个蓝牙项目代码

好的，下面是一个简单的Qt蓝牙项目示例代码，用于连接和通信蓝牙设备：

#include <QBluetoothDeviceDiscoveryAgent>
#include <QBluetoothLocalDevice>
#include <QBluetoothSocket>
#include <QDebug>
#include <QListWidget>
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QPushButton>
#include <QLabel>
#include <QLineEdit>
#include <QMessageBox>

class BluetoothWidget : public QWidget
{
    Q_OBJECT

public:
    BluetoothWidget(QWidget *parent = nullptr) : QWidget(parent)
    {
        // 初始化UI
        initUI();

        // 初始化蓝牙
        initBluetooth();
    }

private slots:
    void startDiscovery()
    {
        // 开始扫描
        deviceListWidget->clear();
        discoveryAgent->start();
        statusLabel->setText(tr("正在扫描蓝牙设备..."));
    }

    void deviceDiscovered(const QBluetoothDeviceInfo &device)
    {
        // 发现新设备
        QListWidgetItem *item = new QListWidgetItem(device.name() + " [" + device.address().toString() + "]");
        item->setData(Qt::UserRole, QVariant::fromValue(device));
        deviceListWidget->addItem(item);
    }

    void deviceSelected(QListWidgetItem *item)
    {
        // 选择设备
        QBluetoothDeviceInfo device = item->data(Qt::UserRole).value<QBluetoothDeviceInfo>();
        connectSocket(device);
    }

    void socketConnected()
    {
        // 连接成功
        statusLabel->setText(tr("已连接蓝牙设备"));
        sendButton->setEnabled(true);
    }

    void socketDisconnected()
    {
        // 断开连接
        statusLabel->setText(tr("蓝牙连接已断开"));
        sendButton->setEnabled(false);
    }

    void sendMessage()
    {
        // 发送消息
        QString message = messageLineEdit->text();
        if (message.isEmpty()) {
            return;
        }
        socket->write(message.toUtf8());
        messageLineEdit->clear();
    }

    void socketError(QBluetoothSocket::SocketError error)
    {
        // 连接错误
        QMessageBox::critical(this, tr("连接错误"), socket->errorString());
        socket->disconnectFromService();
    }

private:
    void initUI()
    {
        // 初始化UI
        QVBoxLayout *mainLayout = new QVBoxLayout(this);

        // 设备列表
        deviceListWidget = new QListWidget(this);
        connect(deviceListWidget, SIGNAL(itemClicked(QListWidgetItem*)), this, SLOT(deviceSelected(QListWidgetItem*)));
        mainLayout->addWidget(deviceListWidget);

        // 操作区域
        QHBoxLayout *operationLayout = new QHBoxLayout();
        mainLayout->addLayout(operationLayout);

        // 开始扫描按钮
        QPushButton *startButton = new QPushButton(tr("开始扫描"), this);
        connect(startButton, SIGNAL(clicked()), this, SLOT(startDiscovery()));
        operationLayout->addWidget(startButton);

        // 发送消息编辑框和按钮
        messageLineEdit = new QLineEdit(this);
        sendButton = new QPushButton(tr("发送"), this);
        sendButton->setEnabled(false);
        connect(sendButton, SIGNAL(clicked()), this, SLOT(sendMessage()));
        operationLayout->addWidget(messageLineEdit);
        operationLayout->addWidget(sendButton);

        // 状态标签
        statusLabel = new QLabel(tr("未连接蓝牙设备"), this);
        mainLayout->addWidget(statusLabel);
    }

    void initBluetooth()
    {
        // 初始化蓝牙
        localDevice = new QBluetoothLocalDevice(this);
        discoveryAgent = new QBluetoothDeviceDiscoveryAgent(this);
        connect(discoveryAgent, SIGNAL(deviceDiscovered(QBluetoothDeviceInfo)), this, SLOT(deviceDiscovered(QBluetoothDeviceInfo)));
        connect(localDevice, SIGNAL(hostModeStateChanged(QBluetoothLocalDevice::HostMode)), this, SLOT(hostModeStateChanged(QBluetoothLocalDevice::HostMode)));
        connect(localDevice, SIGNAL(pairingDisplayPinCode(QBluetoothAddress,QString)), this, SLOT(pairingDisplayPinCode(QBluetoothAddress,QString)));
        connect(localDevice, SIGNAL(pairingDisplayConfirmation(QBluetoothAddress,QString)), this, SLOT(pairingDisplayConfirmation(QBluetoothAddress,QString)));
    }

    void connectSocket(const QBluetoothDeviceInfo &device)
    {
        // 连接蓝牙设备
        socket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol, this);
        connect(socket, SIGNAL(connected()), this, SLOT(socketConnected()));
        connect(socket, SIGNAL(disconnected()), this, SLOT(socketDisconnected()));
        connect(socket, SIGNAL(readyRead()), this, SLOT(socketReadyRead()));
        connect(socket, SIGNAL(error(QBluetoothSocket::SocketError)), this, SLOT(socketError(QBluetoothSocket::SocketError)));
        socket->connectToService(device.address(), QBluetoothUuid(QBluetoothUuid::SerialPort));
    }

    void socketReadyRead()
    {
        // 读取消息
        QByteArray data = socket->readAll();
        qDebug() << "Read data:" << data;
    }

    void hostModeStateChanged(QBluetoothLocalDevice::HostMode mode)
    {
        // 本地蓝牙状态改变
        qDebug() << "Host mode changed:" << mode;
    }

    void pairingDisplayPinCode(const QBluetoothAddress &address, QString pin)
    {
        // 显示配对PIN码
        qDebug() << "Pairing display pin:" << pin;
    }

    void pairingDisplayConfirmation(const QBluetoothAddress &address, QString pin)
    {
        // 显示配对确认对话框
        qDebug() << "Pairing display confirmation:" << pin;
        QBluetoothLocalDevice::Pairing pairing = localDevice->pairingStatus(address);
        localDevice->pairingConfirmation(pairing, true);
    }

    QListWidget *deviceListWidget;
    QLineEdit *messageLineEdit;
    QPushButton *sendButton;
    QLabel *statusLabel;

    QBluetoothLocalDevice *localDevice;
    QBluetoothDeviceDiscoveryAgent *discoveryAgent;
    QBluetoothSocket *socket;
};

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

此示例应该可以帮助您开始编写自己的蓝牙项目。