usb-flash-drive - 在获取 bsdName 之前获取磁盘号

Question

我刚刚遇到一个问题，我可以通过以下代码行获取bsdName，但是如果USB闪存盘中有两个分区，那么我只能获取最后一个bsdName，有人可以告诉我如何从USB驱动器？实际上我想获得每个分区的卷名......提前谢谢

CFStringRef bsdName = ( CFStringRef ) IORegistryEntrySearchCFProperty ( usbDevice,
                                                                               kIOServicePlane,
                                                                               CFSTR ( kIOBSDNameKey ),
                                                                               kCFAllocatorDefault,
                                                                               kIORegistryIterateRecursively );
        NSLog(@"bsdName=%@",bsdName);
        volumeName = deviceNameWithMountPath((NSString*)bsdName);
        //find_hid_device(usbDevice);
        NSLog(@"volume Name=%@",volumeName);

        NSString *mediaType = FindWholeMedia(usbDevice);
        NSLog(@"media type = %@",mediaType);

        //CFRelease(bsdName);

        // Done with this USB device; release the reference added by IOIteratorNext
        kr = IOObjectRelease(usbDevice);        
    }
}



NSString *deviceNameWithMountPath(NSString *mountPath)
{
    DASessionRef session = NULL;
    DADiskRef disk = NULL;
    CFDictionaryRef dd = NULL;
    CFTypeRef val = nil;

    session = DASessionCreate(kCFAllocatorDefault);
    if (!session) {
        NSLog(@"Can't create DiskArb session");
        return nil;
    }

//    DASessionScheduleWithRunLoop(session,
//                                 CFRunLoopGetCurrent(),
//                                 kCFRunLoopDefaultMode);
//    
//    DARegisterDiskAppearedCallback(session, NULL, DiskAppeared, NULL);


    disk = DADiskCreateFromBSDName(kCFAllocatorDefault, session, [mountPath UTF8String]);
    if (!disk) {
        NSLog(@"DADiskCreateFromBSDName(%s) failed", [mountPath UTF8String]);
        return nil;
    }
    dd = DADiskCopyDescription(disk);
    if (!dd) {
        NSLog(@"DADiskCopyDescription(%s) failed", [mountPath UTF8String]);
        return nil;
    }

    CFDictionaryGetValueIfPresent(dd, (kDADiskDescriptionVolumeNameKey), &val);
    DiskAppeared(disk, NULL);
    CFRelease(disk);
    CFRelease(session); 

    return (NSString *)val;
}