How to turn CBUUID into string

Question

I can\'t find any official way to get a UUID string back out of a CBUUID. These UUIDs can be 2 or 16 bytes long.

The goal is to store CBUUIDs in a file somewhere as

Answer 1

Here is swift extension of Brad Larson's answer :

import CoreBluetooth

extension CBUUID {

    func representativeString() -> String {
        let data = self.data

        let bytesToConvert = data.length
        let uuidBytes = UnsafePointer<CUnsignedChar>(data.bytes)
        var outputString = String()

        for currentByteIndex in 0..<bytesToConvert {
            switch currentByteIndex {
            case 3,5,7,9:
                outputString += String(format: "%02x-",uuidBytes[currentByteIndex])
            default:
                outputString += String(format: "%02x",uuidBytes[currentByteIndex])
            }
        }

        return outputString
    }
}

From iOS 7.1 UUIDString property is there but for specific iOS7, above extension is good option.

Answer 2

I know it's been 7 month since it was asked and answered, but... CBUUID is “toll-free bridged” to CFUUID and the easiest way to convert is

 //CBUUID* uuid = descr.UUID;
 NSString* str = CFUUIDCreateString(nil, uuid);