原理：
通过检测Widget::winEvent(MSG *msg, long *result)，当pc上有U盘插拔时，会自动触发这个函数。通过检测此消息是否是WM_DEVICECHANGE就可以
代码：
#include <windows.h>
#include <QMainWindow>
#include <dbt.h>
#include <QString>
#include <QDebug>
private:
char FirstDriveFromMask (ULONG unitmask);
protected:
bool nativeEvent(const QByteArray & eventType, void * message, long*result);
char MainWindow::FirstDriveFromMask(ULONG unitmask)
{
char i;
for (i = 0; i < 26; ++i)
{
if (unitmask & 0x1)
break;
unitmask = unitmask >> 1;
}
return (i + 'A');
}
bool MainWindow::nativeEvent(const QByteArray &eventType, void *message, long *result)
{
MSG* msg = reinterpret_cast<MSG*>(message);
int msgType = msg->message;
if(msgType==WM_DEVICECHANGE)
{
PDEV_BROADCAST_HDR lpdb = (PDEV_BROADCAST_HDR)msg->lParam;
switch (msg->wParam) {
case DBT_DEVICEARRIVAL:
if(lpdb->dbch_devicetype == DBT_DEVTYP_VOLUME)
{
PDEV_BROADCAST_VOLUME lpdbv = (PDEV_BROADCAST_VOLUME)lpdb;
if(lpdbv->dbcv_flags ==0)
{
QString USBDisk = QString(this->FirstDriveFromMask(lpdbv ->dbcv_unitmask));
qDebug() << "USB_Arrived and The USBDisk is: "<<USBDisk ;
}
}
break;
case DBT_DEVICEREMOVECOMPLETE:
if(lpdb->dbch_devicetype == DBT_DEVTYP_VOLUME)
{
PDEV_BROADCAST_VOLUME lpdbv = (PDEV_BROADCAST_VOLUME)lpdb;
if(lpdbv->dbcv_flags == 0)
{
qDebug() << "USB_Removed";
}
}
break;
}
}
return false;
}
