objective-c - 如何快速使用 USBmakebmRequestType

要在objective-c中设置USB请求类型，我使用:
#define USBmakebmRequestType
例如:

IOUSBDevRequest request;
request.bmRequestType = USBmakebmRequestType(kUSBOut, kUSBVendor, kUSBDevice);

我如何快速使用它？ swift 中没有功能 USBmakebmRequestType

最佳答案

我自己实现了:

func USBmakebmRequestType(direction:Int, type:Int, recipient:Int) -> UInt8 {
    return UInt8((direction & kUSBRqDirnMask) << kUSBRqDirnShift)|UInt8((type & kUSBRqTypeMask) << kUSBRqTypeShift)|UInt8(recipient & kUSBRqRecipientMask)
}

用法:

USBmakebmRequestType(direction: kUSBIn, type: kUSBDevice, recipient: kUSBStandard)