这个答案对我有用但是它需要一些修改，例如创建桥接头以导入某些特定的IOKit部件。

首先，将IOKit.framework添加到您的项目中（在“链接的框架和库”中单击“ +”）。

然后创建一个新的空“ .m”文件，无论其名称如何。然后，Xcode将询问是否应创建“桥接标头”。说是。

忽略“ .m”文件。在Xcode刚刚创建的新的“ YOURAPPNAME-Bridging-Header.h”文件中，添加以下行：

#include <IOKit/IOKitLib.h>
#include <IOKit/usb/IOUSBLib.h>
#include <IOKit/hid/IOHIDKeys.h>

现在，您可以使用链接答案中的代码。这是一个简化的版本：

class USBDetector {
    class func monitorUSBEvent() {
        var portIterator: io_iterator_t = 0
        let matchingDict = IOServiceMatching(kIOUSBDeviceClassName)
        let gNotifyPort: IONotificationPortRef = IONotificationPortCreate(kIOMasterPortDefault)
        let runLoopSource: Unmanaged<CFRunLoopSource>! = IONotificationPortGetRunLoopSource(gNotifyPort)
        let gRunLoop: CFRunLoop! = CFRunLoopGetCurrent()
        CFRunLoopAddSource(gRunLoop, runLoopSource.takeRetainedValue(), kCFRunLoopDefaultMode)
        let observer = UnsafeMutablePointer<Void>(unsafeAddressOf(self))
        _ = IOServiceAddMatchingNotification(gNotifyPort,
                                              kIOMatchedNotification,
                                              matchingDict,
                                              deviceAdded,
                                              observer,
                                              &portIterator)
        deviceAdded(nil, iterator: portIterator)
        _ = IOServiceAddMatchingNotification(gNotifyPort,
                                              kIOTerminatedNotification,
                                              matchingDict,
                                              deviceRemoved,
                                              observer,
                                              &portIterator)
        deviceRemoved(nil, iterator: portIterator)
    }
}

func deviceAdded(refCon: UnsafeMutablePointer<Void>, iterator: io_iterator_t) {
    var kr: kern_return_t = KERN_FAILURE
    while case let usbDevice = IOIteratorNext(iterator) where usbDevice != 0 {
        let deviceNameAsCFString = UnsafeMutablePointer<io_name_t>.alloc(1)
        defer {deviceNameAsCFString.dealloc(1)}
        kr = IORegistryEntryGetName(usbDevice, UnsafeMutablePointer(deviceNameAsCFString))
        if kr != KERN_SUCCESS {
            deviceNameAsCFString.memory.0 = 0
        }
        let deviceName = String.fromCString(UnsafePointer(deviceNameAsCFString))
        print("Active device: \(deviceName!)")
        IOObjectRelease(usbDevice)
    }
}

func deviceRemoved(refCon: UnsafeMutablePointer<Void>, iterator: io_iterator_t) {
    // ...
}

注意：deviceAdded并且deviceRemoved必须是函数（不是方法）。

要使用此代码，只需启动观察器：

USBDetector.monitorUSBEvent()

这将列出当前已插入的设备，并且在每个新的USB设备插入/拔出事件中，它将打印设备名称。