Question

我用于获取字节数据的代码，但我没有得到正确的浮点值字节数据

let count = data.length / sizeof(UInt32)

// create array of appropriate length:
var array = [UInt32](count: count, repeatedValue: 0)

// copy bytes into array
data.getBytes(&array, length:count * sizeof(UInt32))

print(array)

Answer 1

Float至NSData：

var float1 : Float = 40.0
let data = NSData(bytes: &float1, length: sizeofValue(float1))
print(data) // <00002042>

...并返回Float：

var float2 : Float = 0
data.getBytes(&float2, length: sizeofValue(float2))
print(float2) // 40.0

（同样适用于Double等其他“简单”类型， Int，...）

使用新的Data类型

更新Swift 3 ：

var float1 : Float = 40.0
let data = Data(buffer: UnsafeBufferPointer(start: &float1, count: 1))
print(data as NSData) // <00002042>

let float2 = data.withUnsafeBytes { $0.pointee } as Float
print(float2) // 40.0

（另见round trip Swift number types to/from Data。）

Answer 2

迅速5 解决方案

从Float到[UInt8]

extension Float {
   var bytes: [UInt8] {
       withUnsafeBytes(of: self, Array.init)
   }
}

用法：

let number: Float = 36.5
let bytes = number.bytes

从[UInt8]到Float

bytes.withUnsafeBytes {
    $0.load(fromByteOffset: 0, as: Float.self)
}

要转换为数据，只需将字节数组转换为Data

let data = Data(bytes)

如何在swift中将float值转换为byte数组？

2 个答案: