HarmonyOS base64和字符串互相转换的方法？

Question

如题：HarmonyOS base64和字符串互相转换的方法？

Answer 1

可参考：

Base64Test() {

  let str = '123456'
  let strArray = new Uint8Array(buffer.from(str).buffer)
  let base64 = new util.Base64Helper();
  let ret = base64.encodeToStringSync(strArray, util.Type.BASIC)
  console.log(ret)

  let textDecoder: util.TextDecoder = util.TextDecoder.create();
  let result: string = textDecoder.decodeToString(base64.decodeSync(ret),{stream:true});
  console.log(result)
}