ok113i平台——qt+tslib支持usb触摸屏热插拔功能实现

问题：重新插拔设备，需要软件重启才能接收到触摸事件 愿因：是因为qt程序的tslib库的操作逻辑是在构造函数里面连接一次usb触摸设备，具体看如下文件内容： /home/forlinx/OK113i-linux-sdk/buildroot/buildroot-201902/dl/qt5base/qtbase/src/platformsupport/input/tslib/qtslib.cpp； 所以重新插拔usb后，qt程序并没有重新连接usb触摸设备，导致没有触摸数据接收； 解决方案： 参考： blog.csdn.net/alone4together/article/details/115269753 参考方案中的代码需要更改一下，完整的qtslib.cpp更改内容如下：

QTsLibMouseHandler::QTsLibMouseHandler(const QString &key, const QString &specification, QObject *parent) : QObject(parent), m_notify(0), m_x(0), m_y(0), m_pressed(0), m_rawMode(false) { m_dev=0; qCDebug(qLcTsLib) << "Initializing tslib plugin" << key << specification; setObjectName(QLatin1String("TSLib Mouse Handler")); ... ... else { qErrnoWarning(errno, "tslib: Cannot open input device %s", device.constData()); } QFileSystemWatcher *m_fileWatcher = new QFileSystemWatcher(this); // QString dev_=device; m_fileWatcher->addPath(QLatin1String("/dev/input/")); // "dev/input/" connect(m_fileWatcher, &QFileSystemWatcher::directoryChanged, this, &QTsLibMouseHandler::handleHotPlugWatch); } void QTsLibMouseHandler::handleHotPlugWatch(const QString &path) { QByteArray device = qgetenv("TSLIB_TSDEVICE"); QFile file(QString::fromLocal8Bit(device)); // shoud be TSLIB_TSDEVICE qCDebug(qLcTsLib) << path << "is changing"; if (file.exists()) { qCDebug(qLcTsLib) << "tslib device disconnected .., try connecting ..."; disconnect(m_notify, 0, 0, 0); if (m_notify){ delete m_notify; m_notify = 0; } // QByteArray device = qgetenv("TSLIB_TSDEVICE"); m_dev = ts_open(device.constData(), 1); if (!m_dev) { qCDebug(qLcTsLib) << " touchscreen doesn't exist"; qErrnoWarning(errno, "ts_open() failed"); } else { if (ts_config(m_dev)){ qErrnoWarning(errno, "ts_config() failed"); } int fd = ts_fd(m_dev); if (fd >= 0) { qCDebug(qLcTsLib) << "tslib device is" << device; m_notify = new QSocketNotifier(fd, QSocketNotifier::Read, this); connect(m_notify, &QSocketNotifier::activated, this, &QTsLibMouseHandler::readMouseData); } else { qErrnoWarning(errno, "tslib: Cannot open input device %s", device.constData()); } return; } qCDebug(qLcTsLib) << path << "is added"; } else { if (m_dev){ ts_close(m_dev); m_dev = 0; } qCDebug(qLcTsLib) << path << "is removed"; } }

改完qtslib.cpp需要编译buildroot，编译后的qtslib.cpp会在如下路径： /home/OK113i-linux-sdk/out/t113_i/ok113i/longan/buildroot/build/qt5base-5.12.5/src/platformsupport/input/tslib/qtslib.cpp 需要注意单独编译的buildroot后，还需要全编译，才会将根文件系统镜像rootfs.ext2更新到系统镜像；