flutter-todos/lib/utils/my_encrypt_util.dart

import 'package:encrypt/encrypt.dart';
class EncryptUtil{


  factory EncryptUtil() => _getInstance();

  static EncryptUtil get instance => _getInstance();
  static EncryptUtil _instance;

  Encrypter _encrypter;
  final iv = IV.fromLength(16);



  EncryptUtil._internal() {
    //初始化
    final theKey = Key.fromUtf8("my 32 length key................");
    _encrypter = Encrypter(AES(theKey));
  }

  static EncryptUtil _getInstance() {
    if (_instance == null) {
      _instance = new EncryptUtil._internal();
    }
    return _instance;
  }


  String encrypt(String value){
    if(value.isEmpty) return"";
    return _encrypter.encrypt(value,iv: iv).base64;  //被加密后的文字
  }

  String decrypt(String value){
    if(value.isEmpty) return"";
    return _encrypter.decrypt64(value??"",iv: iv);
  }
}