如何将数据转换为小端格式？

Question

var val = 1240;

转换为 little endian formate swift 3

例如：1500 (0x5DC)到0xDC050000

Answer 1

let value = UInt16(bigEndian: 1500)

print(String(format:"%04X", value.bigEndian)) //05DC
print(String(format:"%04X", value.littleEndian)) //DC05

确保您实际上正在使用bigEndian初始化程序。

使用 32 位整数：

let value = UInt32(bigEndian: 1500)

print(String(format:"%08X", value.bigEndian)) //000005DC
print(String(format:"%08X", value.littleEndian)) //DC050000

Answer 2

如果您想要 1500 作为小端顺序的字节数组：

var value = UInt32(littleEndian: 1500)

let array = withUnsafeBytes(of: &value) { Array($0) }

如果您希望将其作为Data：

let data = Data(array)

或者，如果您确实希望将其作为十六进制字符串：

let string = array.map { String(format: "%02x", $0) }.joined()

Answer 3

                let timeDevide = self.setmiliSecond/100
                var newTime = UInt32(littleEndian: timeDevide)
                let arrayTime = withUnsafeBytes(of: &newTime) 
                 {Array($0)}
                let timeDelayValue = [0x0B] + arrayTime