您可以扩展数据类型,创建通用方法,获取字节并强制转换或根据需要显式设置结果类型:
extension Data {
func object<T>(at index: Index = 0) -> T {
subdata(in: index..<self.index(index, offsetBy: MemoryLayout<T>.size))
.withUnsafeBytes { $0.load(as: T.self) }
}
}
extension Numeric {
var data: Data {
var source = self
return Data(bytes: &source, count: MemoryLayout<Self>.size)
}
}
let data = Data([0xFF, 0x1F])
let uint16: UInt16 = data.object()
let number1 = uint16.littleEndian
let number2 = uint16.bigEndian
let int16 = data.object() as Int16
let number3 = int16.littleEndian
let number4 = int16.bigEndian
print(number1)
print(number2)
print(number3)
print(number4)
使用Int
进行测试
let random = Int.random(in: 1...100) // 15 UInt32
let data = random.data // 8 bytes [15, 0, 0, 0, 0, 0, 0, 0]
使用 UInt32
进行测试
let random = UInt32.random(in: 1...100) // 90 UInt32
let data = random.data // 4 bytes [90, 0, 0, 0]
使用Double进行测试
let random = Double.random(in: 0...1) // 0.2463145485351322 Double
let data = random.data // 8 bytes [12, 99, 62, 49, 60, 135, 207, 63]
如果您想提取子数据:
let data = Data([0xFF, 0x1F, 0x1F, 0xFF]) // 4 bytes
let uint16: UInt16 = data.object(at: 2) // 65311 littleEndian
let number1 = uint16.littleEndian // 65311
let number2 = uint16.bigEndian // 8191
let int16: Int16 = data.object(at: 2) // -225 littleEndian
let number3 = int16.littleEndian // -225
let number4 = int16.bigEndian // 8191
number1 // 65311
number2 // 8191
number3 // -225
number4 // 8191
sizeofValue(random)
- newacctMemoryLayout.size(ofValue: value)
,而不是sizeofValue
。 - Leo Dabus