HarmonyOS Uint8Array，Int8Array怎么互相转换

Uint8Array是无符合8位整数数组

而Int8Array是有符合8位整数数组

转化的时候需要注意数值溢出

参考：

convertUint8ToInt8Array(u8: Uint8Array): Int8Array {
  const init8Array = new Int8Array(u8.length)
  for (let i = 0; i < u8.length; i++) {
    const value = u8[i];
    init8Array[i] = value > 127 ? value - 256 : value
  }
  return init8Array
}

convertInt8TUint8Array(i8: Int8Array): Uint8Array {
  const uint8Array = new Uint8Array(i8.length)
  for (let i = 0; i < i8.length; i++) {
    const value = i8[i];
    uint8Array[i] = value < 0 ? value + 256 : value
  }
  return uint8Array
}