如何在Swift中将Int转换为NSData？

Question

在Objective-C中,我使用以下代码

1. 将Int变量转换NSData为字节数据包.

   int myScore = 0;
   NSData *packet = [NSData dataWithBytes:&myScore length:sizeof(myScore)];
   

2. 将转换后的NSData变量用于方法.

   [match sendDataToAllPlayers: 
   packet withDataMode: GKMatchSendDataUnreliable 
   error: &error];
   

我尝试将Objective-C代码转换为Swift:

var myScore : Int = 0

func sendDataToAllPlayers(packet: Int!,
            withDataMode mode: GKMatchSendDataMode,
            error: NSErrorPointer) -> Bool {

            return true
}

但是,我无法将Int变量转换为a NSData并将其用作方法.我怎样才能做到这一点？

Answer 1

使用Swift 3.x和4.0:

var myInt = 77
var myIntData = Data(bytes: &myInt, 
                     count: MemoryLayout.size(ofValue: myInt))

Answer 2

要转换Data为Int:

let score = 1000
let data = withUnsafeBytes(of: score) { Data($0) }

要将其转换回来:

e8 03 00 00 00 00 00 00 

Answer 3

对于任何整数类型：

extension FixedWidthInteger {
    var data: Data {
        let data = withUnsafeBytes(of: self) { Data($0) }
        return data
    }
}

例子：

let data = 1.data