HarmonyOS 加密长文本，如何动态获取密文

async function main() { 
  try { 
    const key = 'yau9xxxT6/bwxxxxxKg' 
    let symKeyBlob: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(key).buffer) }; 
    let symGenerator = cryptoFramework.createSymKeyGenerator('AES128'); 
    let symKey: cryptoFramework.SymKey = await symGenerator.convertKey(symKeyBlob); 
    console.info(' convertKey success'); 
    let message = "This is a test"; 
    let plainText: cryptoFramework.DataBlob = { data: new Uint8Array(buffer.from(message, 'utf-8').buffer) }; 
 
    let cipher = cryptoFramework.createCipher('AES128|ECB|PKCS7'); 
    await cipher.init(cryptoFramework.CryptoMode.ENCRYPT_MODE, symKey, null); 
    let encryptText = await cipher.doFinal(plainText); 
    console.log('  encode success') 
 
    let decoder = cryptoFramework.createCipher('AES128|ECB|PKCS7'); 
    await decoder.init(cryptoFramework.CryptoMode.DECRYPT_MODE, symKey, null); 
    let decryptText = await decoder.doFinal(encryptText); 
    console.log(` decode success ${buffer.from(decryptText.data).toString()}`) 
  } catch (e) { 
    console.error(` e = ${e.code} ${e.message}`) 
  } 
}