Converting Byte to UInt8 (Swift 3) - objective-c

Question

I have the following code written in Objective-C:
int port1 = SERVER_DEVICE_PORT;
int port2 = SERVER_DEVICE_PORT>>8;
Byte port1Byte[1] = {port1};
Byte port2Byte[1] = {port2};
NSData *port1Data = [[NSData alloc]initWithBytes: port1Byte length: sizeof(port1Byte)];
NSData *port2Data = [[NSData alloc]initWithBytes: port2Byte length: sizeof(port2Byte)];
I have converted it to Swift 3 like so:
let port1: Int = Int(SERVER_DEVICE_PORT)
let port2: Int = Int(SERVER_DEVICE_PORT) >> 8
let port1Bytes: [UInt8] = [UInt8(port1)]
let port2Bytes: [UInt8] = [UInt8(port2)]
let port1Data = NSData(bytes: port1Bytes, length: port1)
let port2Data = NSData(bytes: port2Bytes, length: port2)
However, with this code I am receiving the following error:
How can this be fixed?

Answer 1

The easiest way in Swift 3 to get the two lowest bytes from a 32 bit value is
var SERVER_DEVICE_PORT : Int32 = 55056
let data = Data(buffer: UnsafeBufferPointer(start: &SERVER_DEVICE_PORT, count: 1))
// or let data = Data(bytes: &SERVER_DEVICE_PORT, count: 2)
let port1Data = data[0]
let port2Data = data[1]
print(port1Data, port2Data)
This results UInt8 values, to get Data use
let port1Data = Data([data[0]])
let port2Data = Data([data[1]])
If – for some reason – the 32bit value is big endian (most significant byte in the smallest address) then port1Data = data[3] and port2Data = data[2].