qt usb 上位机

### 使用 QT 进行上位机开发的数据读取和写入 以下是基于 QT 的上位机开发中常见的数据读取和写入功能的代码示例。这些代码涵盖了串口通信、USB 设备访问以及文件操作等内容。 #### 1. **串口数据读取与写入** 通过 QSerialPort 类可以轻松实现串口通信的功能，这是上位机开发中最常用的一种方式之一[^1]。 ```cpp #include <QCoreApplication> #include <QSerialPort> #include <QSerialPortInfo> #include <QDebug> int main(int argc, char *argv[]) { QCoreApplication a(argc, argv); QSerialPort serial; serial.setPortName("COM3"); // 设置端口号 serial.setBaudRate(QSerialPort::Baud9600); // 设置波特率 serial.setDataBits(QSerialPort::Data8); serial.setParity(QSerialPort::NoParity); serial.setStopBits(QSerialPort::OneStop); serial.setFlowControl(QSerialPort::NoFlowControl); if (!serial.open(QIODevice::ReadWrite)) { // 打开串口 qDebug() << "Failed to open port"; return -1; } QByteArray dataToWrite = "Hello Serial Port"; // 要发送的数据 qint64 bytesWritten = serial.write(dataToWrite); // 发送数据 if (bytesWritten == -1) { qDebug() << "Error writing to serial port"; } else { qDebug() << "Bytes written:" << bytesWritten; } while (serial.waitForReadyRead(100)) { // 等待接收数据 QByteArray receivedData = serial.readAll(); // 接收数据 qDebug() << "Received Data:" << receivedData; } serial.close(); return a.exec(); } ``` --- #### 2. **USB 数据读取与写入** 对于 USB 设备访问，可以通过 libusb 库来完成更底层的操作。下面是一个简单的例子展示如何使用 libusb 来进行基本的读写操作[^2]。 ```c++ #include <libusb-1.0/libusb.h> #include <iostream> void write_to_device(libusb_device_handle* handle, unsigned char endpoint, const uint8_t* buffer, int length) { int actual_length; int result = libusb_bulk_transfer(handle, endpoint | LIBUSB_ENDPOINT_OUT, (unsigned char*)buffer, length, &actual_length, 1000); if (result != 0 || actual_length != length) { std::cerr << "Failed to write to device" << std::endl; } } void read_from_device(libusb_device_handle* handle, unsigned char endpoint, uint8_t* buffer, int length) { int actual_length; int result = libusb_bulk_transfer(handle, endpoint | LIBUSB_ENDPOINT_IN, buffer, length, &actual_length, 1000); if (result != 0 || actual_length != length) { std::cerr << "Failed to read from device" << std::endl; } } int main() { libusb_context* context = nullptr; libusb_init(&context); libusb_device_handle* handle = libusb_open_device_with_vid_pid(context, 0x1234, 0x5678); // 替换为实际VID/PID if (!handle) { std::cerr << "Device not found or could not be opened." << std::endl; return -1; } uint8_t send_buffer[] = {0x01, 0x02, 0x03}; uint8_t receive_buffer[64]; write_to_device(handle, 0x02, send_buffer, sizeof(send_buffer)); read_from_device(handle, 0x81, receive_buffer, sizeof(receive_buffer)); for (size_t i = 0; i < sizeof(receive_buffer); ++i) { std::cout << "Byte[" << i << "]=" << static_cast<int>(receive_buffer[i]) << std::endl; } libusb_close(handle); libusb_exit(context); return 0; } ``` --- #### 3. **Excel 文件数据读取与写入** 当需要处理 Excel 表格时，可以借助 Qt 提供的 ActiveQt 模块中的 `QAxObject` 实现报表导出功能[^3]。 ```cpp #include <QApplication> #include <QFile> #include <QAxObject> #include <QDebug> int main(int argc, char *argv[]) { QApplication app(argc, argv); QAxObject excel("Excel.Application"); excel.setProperty("Visible", false); QAxObject* workbooks = excel.querySubObject("Workbooks"); workbooks->dynamicCall("Add"); QAxObject* workbook = excel.querySubObject("ActiveWorkbook"); QAxObject* sheets = workbook->querySubObject("Sheets"); QAxObject* sheet = sheets->querySubObject("Item(int)", 1); sheet->setProperty("Name", "Sheet1"); sheet->querySubObject("Cells(int,int)", 1, 1)->dynamicCall("SetValue(const QVariant&)", QString("Test Value")); workbook->dynamicCall("SaveAs(const QString&)", QString("output.xlsx")); workbook->dynamicCall("Close(Boolean)", false); excel.dynamicCall("Quit"); return app.exec(); } ``` --- #### 4. **加密与解密功能集成** 为了保护传输过程中的敏感数据，可以在程序中加入加密和解密模块。以下是一个简单的 AES 加密/解密示例[^4]。 ```cpp #include <QString> #include <QCryptographicHash> #include <QByteArray> QString encryptString(const QString& plainText, const QString& key) { QCryptographicHash hash(QCryptographicHash::Sha256); hash.addData(key.toUtf8()); QByteArray hashedKey = hash.result(); QByteArray cipher; QAESEncryption aesEncryption(hashedKey, QAESEncryption::AES_256_CBC); cipher.append(aesEncryption.encrypt(plainText.toUtf8())); return QString(cipher.toBase64()); } QString decryptString(const QString& encryptedText, const QString& key) { QCryptographicHash hash(QCryptographicHash::Sha256); hash.addData(key.toUtf8()); QByteArray hashedKey = hash.result(); QByteArray decrypted; QAESEncryption aesDecryption(hashedKey, QAESEncryption::AES_256_CBC); decrypted = aesDecryption.decrypt(QByteArray::fromBase64(encryptedText.toUtf8())); return QString(decrypted); } // 测试函数 QString testKey = "my_secret_key"; QString originalText = "This is a secret message."; QString encryptedText = encryptString(originalText, testKey); qDebug() << "Encrypted Text:" << encryptedText; QString decryptedText = decryptString(encryptedText, testKey); qDebug() << "Decrypted Text:" << decryptedText; ``` ---