HarmonyOS string转Uint8Array

string转Uint8Array示例代码：

stringToUint8Array(str: string): Uint8Array {
  try {
    let textEncoder = new util.TextEncoder("utf-8");
    let array: Uint8Array = textEncoder.encodeInto(str);
    return array
  } catch (err) {
    QDLogUtils.error(`stringToUint8Array = ${err}`)
    return new Uint8Array()
  }
}