socket->connectToService(address, QBluetoothUuid(QBluetoothUuid::SerialPort), QIODevice::ReadWrite);

This line of code establishes a Bluetooth socket connection to a service identified by the given address and UUID. The QIODevice::ReadWrite flag indicates that the socket will be used for bidirectional communication. Specifically, the code uses the QBluetoothUuid::SerialPort identifier to establish a serial port profile connection to the specified Bluetooth device. Once the connection is established, data can be exchanged between the client and the server using the socket.

相关问题

void WBlueTooth::connectToDevice(const QString& deviceAddress) { if (!localDevice->isValid()) { _ui->recv->append("本地蓝牙设备不可用"); return; } QBluetoothAddress address(deviceAddress); QBluetoothDeviceInfo deviceInfo(address); if (!deviceInfo.isValid()) { _ui->recv->append("无效的蓝牙设备地址"); return; } QBluetoothSocket* socket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol); socket->connectToService(deviceInfo.address(), QBluetoothUuid(QBluetoothUuid::SerialPort)); connect(socket, &QBluetoothSocket::connected, this, [=]() { _ui->recv->append("已连接到设备：" + deviceInfo.name()); // 连接成功后可以执行其他操作 }); connect(socket, QOverload<QBluetoothSocket::SocketError>::of(&QBluetoothSocket::error), this, [=](QBluetoothSocket::SocketError error) { _ui->recv->append("蓝牙连接错误：" + QString::number(error)); // 处理连接错误的情况 }); }其中这行代码有错QBluetoothDeviceInfo deviceInfo(address);错误类型error: no matching constructor for initialization of 'QBluetoothDeviceInfo'

这个错误是因为在这行代码中，QBluetoothDeviceInfo类没有接受QBluetoothAddress类型参数的构造函数。要实例化QBluetoothDeviceInfo对象，可以使用QBluetoothDeviceDiscoveryAgent类的静态函数来获取设备信息。以下是修正后的代码示例：

void WBlueTooth::connectToDevice(const QString& deviceAddress)
{
    if (!localDevice->isValid()) {
        _ui->recv->append("本地蓝牙设备不可用");
        return;
    }

    QBluetoothAddress address(deviceAddress);
    QBluetoothDeviceInfo deviceInfo = QBluetoothDeviceDiscoveryAgent::remoteDevice(address);
    if (!deviceInfo.isValid()) {
        _ui->recv->append("无效的蓝牙设备地址");
        return;
    }

    QBluetoothSocket* socket = new QBluetoothSocket(QBluetoothServiceInfo::RfcommProtocol);
    socket->connectToService(deviceInfo.address(), QBluetoothUuid(QBluetoothUuid::SerialPort));
    connect(socket, &QBluetoothSocket::connected, this, [=]() {
        _ui->recv->append("已连接到设备：" + deviceInfo.name());
        // 连接成功后可以执行其他操作
    });
    connect(socket, QOverload<QBluetoothSocket::SocketError>::of(&QBluetoothSocket::error), this, [=](QBluetoothSocket::SocketError error) {
        _ui->recv->append("蓝牙连接错误：" + QString::number(error));
        // 处理连接错误的情况
    });
}

修正后的代码中使用了`QBluetoothDeviceDiscoveryAgent::remoteDevice`函数来获取设备信息，并将其赋值给`deviceInfo`对象。这样就可以避免了构造函数的错误。

QIODevice::write (QSerialPort): device not open

在Qt中，`QIODevice::write()`是一个用于向设备写入数据的方法，特别是对于像串口（QSerialPort）这样的流式输入输出设备。当遇到`device not open`错误提示时，意味着你在尝试写入数据之前，串口设备并没有打开（即调用了`open()`函数）。串口需要先通过`open()`函数指定连接模式（如`QIODevice::ReadOnly`, `QIODevice::WriteOnly` 或 `QIODevice::ReadWrite`）并成功建立连接后，才能进行读写操作。

以下是基本的使用流程：

QSerialPort serialPort("COM1", QIODevice::ReadWrite); // 连接到串口 COM1，设置为双向通信
if (!serialPort.open(QIODevice::WriteOnly)) { // 检查是否成功打开
    qDebug() << "Error opening serial port.";
} else {
    QByteArray data("Hello, Serial Port!");
    qint64 bytesWritten = serialPort.write(data); // 写入数据
    if (bytesWritten > 0) {
        qDebug() << "Data written successfully.";
    } else {
        qDebug() << "Failed to write data.";
    }
}

如果`open()`失败，你需要处理这个异常，可能是由于串口不存在、权限不足或者其他硬件问题。