Windows API实现弹出U盘

/*可实现性未验证*/

#include 
#include 
#include 
#include 

#define LOCK_TIMEOUT        10000       // 10 Seconds
   #define LOCK_RETRIES        20
/***************
Function：	UninstallUsb
Description：	根据盘符将usb设备弹出
Parameters：
discId	要弹出的盘符
Returns：
-1	失败
0	成功
***************/
static int UninstallUsb(char *discId)
{
    DWORD accessMode = GENERIC_WRITE | GENERIC_READ;
    DWORD shareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
    HANDLE hDevice;
    long	bResult = 0;
    DWORD retu = 0;
    DWORD dwError;
    DWORD dwBytesReturned;
    DWORD dwSleepAmount;
    int nTryCount;
    char szDriv[10];


    if(discId == NULL){
        return 0;
    }
    dwSleepAmount = LOCK_TIMEOUT/LOCK_RETRIES;
    sprintf(szDriv,"\\\\.\\%s:",discId);
    hDevice = CreateFile(szDriv,accessMode,shareMode,NULL,OPEN_EXISTING,0,NULL);
    if(hDevice == INVALID_HANDLE_VALUE){
        printf("uninstallusb createfile failed error:%d\n",GetLastError());
        return -1;
    }
#if 0
    //此循环是用于锁定要弹出的U盘设备，如果U盘在使用，则循环等待
    // Do this in a loop until a timeout period has expired
    for(nTryCount = 0;nTryCount < LOCK_RETRIES;nTryCount++){
        if(DeviceIoControl(hDevice,FSCTL_LOCK_VOLUME,NULL,0,NULL,0,&dwBytesReturned,NULL)){
            break;
        }
    }


    //卸载U盘卷，不论是否在使用
    dwBytesReturned = 0;
    if(!DeviceIoControl(hDevice,FSCTL_DISMOUNT_VOLUME,NULL,0,NULL,0,&dwBytesReturned,NULL)){
        printf("deviceIoConrol FSCTL_DISMOUNT_VOLUME failed\n");
    }
#endif


    dwBytesReturned = 0;
    PREVENT_MEDIA_REMOVAL PMRBuffer;
    PMRBuffer.PreventMediaRemoval = FALSE;
    if(!DeviceIoControl(hDevice,IOCTL_STORAGE_MEDIA_REMOVAL,&PMRBuffer,sizeof(PREVENT_MEDIA_REMOVAL),NULL,0,&dwBytesReturned,NULL)){
        printf("DeviceIoControl IOCTL_STORAGE_MEDIA_REMOVAL failed:%d\n",GetLastError());
    }
    bResult = DeviceIoControl(hDevice,IOCTL_STORAGE_EJECT_MEDIA,NULL,0,NULL,0,&retu,NULL);
    if(!bResult){
        CloseHandle(hDevice);
        printf("uninstallusb DeviceIoControl failed error:%d\n",GetLastError());
        return -1;
    }
    CloseHandle(hDevice);
    
    return 0;
}


int main()
{
    UninstallUsb("H");
    return 0;
}