{"id":117,"date":"2026-05-19T16:21:51","date_gmt":"2026-05-19T08:21:51","guid":{"rendered":"https:\/\/tachyoncat.top\/?p=117"},"modified":"2026-05-19T16:25:22","modified_gmt":"2026-05-19T08:25:22","slug":"dart%e5%9f%ba%e6%9c%ac%e8%af%ad%e6%b3%953","status":"publish","type":"post","link":"https:\/\/tachyoncat.top\/index.php\/2026\/05\/19\/dart%e5%9f%ba%e6%9c%ac%e8%af%ad%e6%b3%953\/","title":{"rendered":"Dart\u57fa\u672c\u8bed\u6cd53 <\u7c7b\u3001\u7ee7\u627f\u3001\u91cd\u5199\u3001\u6cdb\u578b\u3001\u62bd\u8c61\u7c7b\u3001\u5b9e\u73b0>"},"content":{"rendered":"

Dart \u7c7b\u4e0e\u9762\u5411\u5bf9\u8c61<\/h1>\n

1. \u7c7b\u7684\u57fa\u672c\u5199\u6cd5<\/h2>\n

\u7c7b = \u5c5e\u6027\uff08\u6570\u636e\uff09+ \u6784\u9020\u51fd\u6570 + \u65b9\u6cd5\uff08\u884c\u4e3a\uff09<\/h3>\n
class Person {\n  \/\/ ========== \u5c5e\u6027\uff08Fields\uff09==========\n  String name;    \/\/ \u59d3\u540d\n  int age;        \/\/ \u5e74\u9f84\n\n  \/\/ ========== \u6784\u9020\u51fd\u6570 ==========\n  Person(this.name, this.age);\n\n  \/\/ ========== \u65b9\u6cd5\uff08Functions\uff09==========\n  void introduce() {\n    print('\u6211\u53eb name\uff0c\u4eca\u5e74<\/span>age \u5c81');\n  }\n\n  bool isAdult() {\n    return age >= 18;\n  }\n}\n\n\/\/ \u4f7f\u7528\u7c7b\nvoid main() {\n  var person = Person('\u5f20\u4e09', 25);\n  person.introduce();  \/\/ \u6211\u53eb \u5f20\u4e09\uff0c\u4eca\u5e74 25 \u5c81\n  print(person.isAdult());  \/\/ true\n}\n<\/code><\/pre>\n
\n
2. this \u5173\u952e\u5b57\u8be6\u89e3<\/h2>\n
this<\/code> \u7684\u6838\u5fc3\u4f5c\u7528\uff1a\u6307\u5411\u5f53\u524d\u5bf9\u8c61<\/strong><\/h3>\n
\u53ef\u4ee5\u628a this<\/code> \u7406\u89e3\u4e3a\"\u6211\u81ea\u5df1\"\uff0c\u5b83\u6307\u5411\u8c03\u7528\u8be5\u65b9\u6cd5\u7684\u5bf9\u8c61\u3002<\/p>\n
\u573a\u666f\u4e00\uff1athis<\/code> \u7528\u4e8e\u533a\u5206\u5c5e\u6027\u548c\u5c40\u90e8\u53d8\u91cf<\/h3>\n
class Dog {\n  String name;    \/\/ \u5c5e\u6027\n  int age;         \/\/ \u5c5e\u6027\n\n  \/\/ \u53c2\u6570\u540d\u548c\u5c5e\u6027\u540d\u76f8\u540c\uff0c\u9700\u8981\u7528 this \u533a\u5206\n  Dog(this.name, this.age);\n\n  void speak() {\n    String name = '\u5c40\u90e8\u53d8\u91cf';  \/\/ \u5c40\u90e8\u53d8\u91cf\n    print('\u6211\u53eb {this.name}');  \/\/ this.name \u6307\u5411\u5c5e\u6027\n    print('\u6211\u53eb<\/span>name');        \/\/ \u6307\u5411\u5c40\u90e8\u53d8\u91cf\n  }\n}\n\nvoid main() {\n  var dog = Dog('\u65fa\u8d22', 3);\n  dog.speak();\n  \/\/ \u8f93\u51fa\uff1a\n  \/\/ \u6211\u53eb \u65fa\u8d22\n  \/\/ \u6211\u53eb \u5c40\u90e8\u53d8\u91cf\n}\n<\/code><\/pre>\n
\u573a\u666f\u4e8c\uff1athis<\/code> \u7528\u4e8e\u6784\u9020\u51fd\u6570\u53c2\u6570\u4f20\u503c<\/h3>\n
class Person {\n  String name;\n  int age;\n  String city;\n\n  \/\/ \u8bed\u6cd5\u7cd6\uff1athis.\u5c5e\u6027\u540d \u76f4\u63a5\u63a5\u6536\u53c2\u6570\u5e76\u8d4b\u503c\u7ed9\u5c5e\u6027\n  Person(this.name, this.age);  \/\/ city \u6ca1\u4f20\uff0c\u9ed8\u8ba4\u4e3a null\n\n  \/\/ \u7b49\u4ef7\u4e8e\uff1a\n  \/\/ Person(String name, int age) {\n  \/\/   this.name = name;\n  \/\/   this.age = age;\n  \/\/ }\n}\n<\/code><\/pre>\n
\u573a\u666f\u4e09\uff1athis<\/code> \u7528\u4e8e\u65b9\u6cd5\u94fe\u5f0f\u8c03\u7528<\/h3>\n
class Builder {\n  String name = '';\n  int age = 0;\n\n  Builder setName(String name) {\n    this.name = name;\n    return this;  \/\/ \u8fd4\u56de\u81ea\u5df1\uff0c\u5b9e\u73b0\u94fe\u5f0f\u8c03\u7528\n  }\n\n  Builder setAge(int age) {\n    this.age = age;\n    return this;\n  }\n}\n\nvoid main() {\n  var builder = Builder()\n    ..setName('\u5f20\u4e09')   \/\/ \u7ea7\u8054\u8fd0\u7b97\u7b26\n    ..setAge(25);\n\n  \/\/ \u7b49\u4ef7\u4e8e\u94fe\u5f0f\u8c03\u7528\uff1a\n  var builder2 = Builder()\n    .setName('\u674e\u56db')\n    .setAge(30);\n}\n<\/code><\/pre>\n
\u573a\u666f\u56db\uff1a\u7ee7\u627f\u4e2d\u7684 this<\/code><\/h3>\n
class Animal {\n  String name;\n  Animal(this.name);\n}\n\nclass Dog extends Animal {\n  int age;\n\n  \/\/ super \u7528\u4e8e\u8c03\u7528\u7236\u7c7b\u6784\u9020\u51fd\u6570\n  \/\/ this \u7528\u4e8e\u521d\u59cb\u5316\u5f53\u524d\u7c7b\u7684\u5c5e\u6027\n  Dog(String name, this.age) : super(name);\n}\n\nvoid main() {\n  var dog = Dog('\u65fa\u8d22', 3);\n  print(dog.name);  \/\/ \u65fa\u8d22\n  print(dog.age);   \/\/ 3\n}\n<\/code><\/pre>\n
this<\/code> \u5feb\u901f\u8bb0\u5fc6<\/h3>\n\n\n\n\n\n\n\n\n
\u573a\u666f<\/th>\n\u4f5c\u7528<\/th>\n<\/tr>\n<\/thead>\n
this.\u5c5e\u6027\u540d<\/code><\/td>\n\u533a\u5206\u540c\u540d\u5c5e\u6027\u548c\u5c40\u90e8\u53d8\u91cf<\/td>\n<\/tr>\n
this.name<\/code> \u5728\u6784\u9020\u51fd\u6570\u53c2\u6570<\/td>\n\u8bed\u6cd5\u7cd6\uff0c\u81ea\u52a8\u8d4b\u503c\u5c5e\u6027<\/td>\n<\/tr>\n
return this<\/code><\/td>\n\u8fd4\u56de\u5f53\u524d\u5bf9\u8c61\uff0c\u5b9e\u73b0\u94fe\u5f0f\u8c03\u7528<\/td>\n<\/tr>\n
super.name<\/code><\/td>\n\u8c03\u7528\u7236\u7c7b\u6784\u9020\u51fd\u6570<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n
3. \u7c7b\u7684\u7ee7\u627f<\/h2>\n
\u57fa\u672c\u8bed\u6cd5<\/h3>\n
\/\/ \u7236\u7c7b\nclass Animal {\n  String name;\n\n  Animal(this.name);\n\n  void eat() {\n    print('name \u6b63\u5728\u5403\u4e1c\u897f');\n  }\n}\n\n\/\/ \u5b50\u7c7b - \u4f7f\u7528 extends \u7ee7\u627f\nclass Dog extends Animal {\n  String breed;  \/\/ \u65b0\u589e\u5c5e\u6027\n\n  Dog(String name, this.breed) : super(name);  \/\/ super \u8c03\u7528\u7236\u7c7b\u6784\u9020\u51fd\u6570\n\n  void bark() {\n    print('<\/span>name \u6c6a\u6c6a\u53eb');\n  }\n}\n\nvoid main() {\n  var dog = Dog('\u65fa\u8d22', '\u91d1\u6bdb');\n  dog.eat();   \/\/ \u7ee7\u627f\u81ea\u7236\u7c7b\u7684\u65b9\u6cd5\n  dog.bark();  \/\/ \u5b50\u7c7b\u81ea\u5df1\u7684\u65b9\u6cd5\n}\n<\/code><\/pre>\n
\u7ee7\u627f\u7684\u89c4\u5219<\/h3>\n
    \n
  1. \u5355\u7ee7\u627f<\/strong>\uff1aDart \u53ea\u652f\u6301\u5355\u7ee7\u627f\uff0c\u4e00\u4e2a\u7c7b\u53ea\u80fd\u7ee7\u627f\u4e00\u4e2a\u7236\u7c7b<\/li>\n
  2. \u7ee7\u627f\u5c5e\u6027\u548c\u65b9\u6cd5<\/strong>\uff1a\u5b50\u7c7b\u81ea\u52a8\u83b7\u5f97\u7236\u7c7b\u7684\u5c5e\u6027\u548c\u65b9\u6cd5<\/li>\n
  3. \u53ef\u65b0\u589e\u6216\u91cd\u5199<\/strong>\uff1a\u5b50\u7c7b\u53ef\u4ee5\u6dfb\u52a0\u65b0\u5c5e\u6027\/\u65b9\u6cd5\uff0c\u4e5f\u53ef\u4ee5\u91cd\u5199\u7236\u7c7b\u65b9\u6cd5<\/li>\n<\/ol>\n
    \n
    4. \u65b9\u6cd5\u91cd\u5199\uff08Override\uff09<\/h2>\n
    \u4ec0\u4e48\u662f\u65b9\u6cd5\u91cd\u5199\uff1f<\/h3>\n
    \u5b50\u7c7b\u91cd\u65b0\u5b9a\u4e49\u7236\u7c7b\u4e2d\u5df2\u6709\u7684\u65b9\u6cd5\uff0c\u53eb\u65b9\u6cd5\u91cd\u5199\u3002<\/p>\n
    \u91cd\u5199\u89c4\u5219<\/h3>\n
      \n
    1. \u4f7f\u7528 @override<\/code> \u6ce8\u89e3\uff08\u5efa\u8bae\u6dfb\u52a0\uff0c\u4ee3\u7801\u66f4\u6e05\u6670\uff09<\/li>\n
    2. \u65b9\u6cd5\u7b7e\u540d\uff08\u53c2\u6570\u5217\u8868\uff09\u5fc5\u987b\u4e0e\u7236\u7c7b\u4e00\u81f4<\/li>\n
    3. \u65b9\u6cd5\u4f53\u53ef\u4ee5\u81ea\u5b9a\u4e49<\/li>\n<\/ol>\n
      \u793a\u4f8b<\/h3>\n
      class Animal {\n  String name;\n\n  Animal(this.name);\n\n  void sound() {\n    print('name \u53d1\u51fa\u58f0\u97f3');\n  }\n}\n\nclass Cat extends Animal {\n  Cat(String name) : super(name);\n\n  @override\n  void sound() {  \/\/ \u91cd\u5199\u7236\u7c7b\u7684 sound \u65b9\u6cd5\n    print('<\/span>name \u55b5\u55b5\u53eb');\n  }\n\n  void climb() {\n    print('name \u5728\u722c\u6811');\n  }\n}\n\nclass Dog extends Animal {\n  Dog(String name) : super(name);\n\n  @override\n  void sound() {  \/\/ \u91cd\u5199\u7236\u7c7b\u7684 sound \u65b9\u6cd5\n    print('<\/span>name \u6c6a\u6c6a\u53eb');\n  }\n}\n\nvoid main() {\n  var cat = Cat('\u54aa\u54aa');\n  var dog = Dog('\u65fa\u8d22');\n\n  cat.sound();  \/\/ \u54aa\u54aa \u55b5\u55b5\u53eb\uff08\u8c03\u7528\u91cd\u5199\u540e\u7684\u65b9\u6cd5\uff09\n  dog.sound();  \/\/ \u65fa\u8d22 \u6c6a\u6c6a\u53eb\uff08\u8c03\u7528\u91cd\u5199\u540e\u7684\u65b9\u6cd5\uff09\n}\n<\/code><\/pre>\n
      \u91cd\u5199 vs \u91cd\u8f7d\uff08\u533a\u522b\uff09<\/h3>\n\n\n\n\n\n\n
      \u6982\u5ff5<\/th>\n\u8bf4\u660e<\/th>\nDart \u652f\u6301<\/th>\n<\/tr>\n<\/thead>\n
      \u91cd\u5199\uff08Override\uff09<\/strong><\/td>\n\u5b50\u7c7b\u91cd\u65b0\u5b9a\u4e49\u7236\u7c7b\u65b9\u6cd5<\/td>\n\u2705 \u652f\u6301<\/td>\n<\/tr>\n
      \u91cd\u8f7d\uff08Overload\uff09<\/strong><\/td>\n\u540c\u540d\u65b9\u6cd5\u4e0d\u540c\u53c2\u6570<\/td>\n\u274c \u4e0d\u652f\u6301<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \n
      5. \u6cdb\u578b\uff08Generics\uff09\u8be6\u89e3<\/h2>\n
      \u4e3a\u4ec0\u4e48\u8981\u7528\u6cdb\u578b\uff1f<\/h3>\n
      \u95ee\u9898<\/strong>\uff1a\u5982\u679c\u6709\u591a\u79cd\u7c7b\u578b\u9700\u8981\u5b58\u50a8\uff0c\u6bcf\u79cd\u90fd\u5199\u4e00\u4e2a\u7c7b\u592a\u9ebb\u70e6\u4e86<\/p>\n
      \/\/ \u274c \u6ca1\u6709\u6cdb\u578b - \u9700\u8981\u5199\u591a\u4e2a\u7c7b\nclass IntBox {\n  int? value;\n}\n\nclass StringBox {\n  String? value;\n}\n\nclass DoubleBox {\n  double? value;\n}\n\n\/\/ \u2705 \u6709\u6cdb\u578b - \u4e00\u4e2a\u7c7b\u641e\u5b9a\u6240\u6709\u7c7b\u578b\nclass Box<T> {  \/\/ T \u662f\u7c7b\u578b\u53c2\u6570\uff0c\u53ef\u4ee5\u662f\u4efb\u4f55\u7c7b\u578b\n  T? value;\n}\n\nvoid main() {\n  var intBox = Box<int>();\n  var stringBox = Box<String>();\n  var doubleBox = Box<double>();\n\n  intBox.value = 42;\n  stringBox.value = 'Hello';\n  doubleBox.value = 3.14;\n\n  print(intBox.value);      \/\/ 42\n  print(stringBox.value);   \/\/ Hello\n  print(doubleBox.value);   \/\/ 3.14\n}\n<\/code><\/pre>\n
      \u6cdb\u578b\u7684\u672c\u8d28<\/h3>\n
      \n  \u6cdb\u578b = \"\u7c7b\u578b\u53c2\u6570\"<\/strong>
      \n  \u7528\u4e00\u4e2a\u5360\u4f4d\u7b26\uff08T\uff09<\/strong>\u4ee3\u66ff\u5177\u4f53\u7c7b\u578b\uff0c\u4f7f\u7528\u65f6\u518d\u6307\u5b9a\u5177\u4f53\u7c7b\u578b\n<\/p><\/blockquote>\n
      \u6cdb\u578b\u8bed\u6cd5<\/h3>\n
      \u57fa\u672c\u8bed\u6cd5<\/h4>\n
      class \u7c7b\u540d<\u7c7b\u578b\u53c2\u6570> {\n  \u7c7b\u578b\u53c2\u6570 \u5c5e\u6027\u540d;\n}\n\n\/\/ \u5e38\u89c1\u7c7b\u578b\u53c2\u6570\u540d\uff1aT\u3001E\u3001K\u3001V\u3001R\uff08\u53ea\u662f\u4e00\u79cd\u7ea6\u5b9a\uff09\n<\/code><\/pre>\n
      \u5e38\u89c1\u547d\u540d\u7ea6\u5b9a<\/h4>\n\n\n\n\n\n\n\n\n\n
      \u547d\u540d<\/th>\n\u542b\u4e49<\/th>\n\u793a\u4f8b<\/th>\n<\/tr>\n<\/thead>\n
      T<\/code><\/td>\nType\uff08\u7c7b\u578b\uff09<\/td>\nList<T><\/code><\/td>\n<\/tr>\n
      E<\/code><\/td>\nElement\uff08\u5143\u7d20\uff09<\/td>\nSet<E><\/code><\/td>\n<\/tr>\n
      K<\/code><\/td>\nKey\uff08\u952e\uff09<\/td>\nMap<K, V><\/code><\/td>\n<\/tr>\n
      V<\/code><\/td>\nValue\uff08\u503c\uff09<\/td>\nMap<K, V><\/code><\/td>\n<\/tr>\n
      R<\/code><\/td>\nReturn\uff08\u8fd4\u56de\u503c\uff09<\/td>\nR Function()<\/code><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \u6cdb\u578b\u7528\u6cd5\u793a\u4f8b<\/h3>\n
      \u6cdb\u578b\u7c7b<\/h4>\n
      class Stack<T> {\n  final List<T> _items = [];\n\n  void push(T item) => _items.add(item);\n  T pop() => _items.removeLast();\n}\n\n\/\/ \u4f7f\u7528\nvar intStack = Stack<int>();\nvar stringStack = Stack<String>();\n<\/code><\/pre>\n
      \u6cdb\u578b\u65b9\u6cd5<\/h4>\n
      T first<T>(List<T> list) {\n  return list[0];\n}\n\n\/\/ \u4f7f\u7528\nfirst<int>([1, 2, 3]);      \/\/ \u8fd4\u56de 1\nfirst<String>(['a', 'b']); \/\/ \u8fd4\u56de 'a'\n<\/code><\/pre>\n
      \u6cdb\u578b\u63a5\u53e3<\/h4>\n
      abstract class Repository<T> {\n  Future<T> get(int id);\n  Future<List<T>> getAll();\n}\n\nclass UserRepository implements Repository<User> {\n  @override\n  Future<User> get(int id) async {\n    \/\/ \u5b9e\u73b0\n  }\n\n  @override\n  Future<List<User>> getAll() async {\n    \/\/ \u5b9e\u73b0\n  }\n}\n<\/code><\/pre>\n
      \u591a\u7c7b\u578b\u53c2\u6570<\/h4>\n
      class Pair<K, V> {\n  K first;\n  V second;\n\n  Pair(this.first, this.second);\n}\n\n\/\/ \u4f7f\u7528\nvar pair = Pair<String, int>('\u5e74\u9f84', 25);\n<\/code><\/pre>\n
      \u6cdb\u578b\u7ea6\u675f<\/h3>\n
      \u9650\u5236\u6cdb\u578b\u5fc5\u987b\u662f\u67d0\u4e2a\u7c7b\u578b\u7684\u5b50\u7c7b\uff1a<\/p>\n
      class Printable<T extends Comparable> {\n  void print(T value) {\n    print(value.toString());\n  }\n}\n\n\/\/ \u4f7f\u7528\nvar p = Printable<int>();  \/\/ \u2705 int \u5b9e\u73b0\u4e86 Comparable\n\/\/ var p = Printable<String>();  \/\/ \u274c String \u4e5f\u5b9e\u73b0\u4e86 Comparable\uff0c\u6240\u4ee5\u4e5f\u53ef\u4ee5\n<\/code><\/pre>\n
      \u6cdb\u578b\u7684\u597d\u5904<\/h3>\n\n\n\n\n\n\n\n
      \u597d\u5904<\/th>\n\u8bf4\u660e<\/th>\n<\/tr>\n<\/thead>\n
      \u4ee3\u7801\u590d\u7528<\/strong><\/td>\n\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u5904\u7406\u591a\u79cd\u7c7b\u578b<\/td>\n<\/tr>\n
      \u7c7b\u578b\u5b89\u5168<\/strong><\/td>\n\u7f16\u8bd1\u65f6\u68c0\u67e5\u7c7b\u578b\u9519\u8bef<\/td>\n<\/tr>\n
      \u6027\u80fd\u4f18\u5316<\/strong><\/td>\n\u4e0d\u9700\u8981\u8fd0\u884c\u65f6\u7c7b\u578b\u68c0\u67e5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \n
      6. \u7efc\u5408\u793a\u4f8b\uff1a\u5b8c\u6574\u7c7b\u7ed3\u6784<\/h2>\n
      \/\/ \u6cdb\u578b\u7236\u7c7b\nabstract class Storage<T> {\n  void save(T item);\n  T? get(int id);\n  List<T> getAll();\n}\n\n\/\/ \u5b50\u7c7b\u7ee7\u627f + \u91cd\u5199 + \u6cdb\u578b\nclass UserStorage implements Storage<User> {\n  final List<User> _users = [];\n\n  @override\n  void save(User user) {\n    _users.add(user);\n  }\n\n  @override\n  User? get(int id) {\n    return id < _users.length ? _users[id] : null;\n  }\n\n  @override\n  List<User> getAll() {\n    return List.from(_users);\n  }\n}\n\nclass User {\n  String name;\n  int age;\n\n  User(this.name, this.age);\n\n  @override\n  String toString() => 'User(name,<\/span>age)';\n}\n\nvoid main() {\n  var storage = UserStorage();\n\n  storage.save(User('\u5f20\u4e09', 25));\n  storage.save(User('\u674e\u56db', 30));\n\n  print(storage.get(0));      \/\/ User(\u5f20\u4e09, 25)\n  print(storage.getAll());     \/\/ [User(\u5f20\u4e09, 25), User(\u674e\u56db, 30)]\n}\n<\/code><\/pre>\n
      \n
      7. \u5feb\u901f\u8bb0\u5fc6<\/h2>\n
      \n  \ud83c\udfaf this<\/code> \u7684\u4f5c\u7528<\/strong>\uff1a\u6307\u5411\u5f53\u524d\u5bf9\u8c61\uff0c\u533a\u5206\u5c5e\u6027\u4e0e\u5c40\u90e8\u53d8\u91cf\uff0c\u5b9e\u73b0\u94fe\u5f0f\u8c03\u7528<\/p>\n
        \ud83c\udfaf \u7ee7\u627f<\/strong>\uff1aextends<\/code> \u7ee7\u627f\u7236\u7c7b\uff0csuper()<\/code> \u8c03\u7528\u7236\u7c7b\u6784\u9020\u51fd\u6570<\/p>\n
        \ud83c\udfaf \u65b9\u6cd5\u91cd\u5199<\/strong>\uff1a@override<\/code> \u6ce8\u89e3 + \u7b7e\u540d\u4e00\u81f4 + \u81ea\u5b9a\u4e49\u65b9\u6cd5\u4f53<\/p>\n
        \ud83c\udfaf \u6cdb\u578b<\/strong>\uff1a\u7528 <T><\/code> \u8868\u793a\"\u7c7b\u578b\u53c2\u6570\"\uff0c<T><\/code> \u5199\u5728\u4f7f\u7528\u65f6\u66ff\u6362\u4e3a\u5177\u4f53\u7c7b\u578b\n<\/p><\/blockquote>\n
      \n
      8. abstract\uff08\u62bd\u8c61\u7c7b\uff09<\/h2>\n
      \u4ec0\u4e48\u662f\u62bd\u8c61\u7c7b\uff1f<\/h3>\n
      \u7528 abstract<\/code> \u4fee\u9970\u7684\u7c7b\u4e0d\u80fd\u76f4\u63a5\u5b9e\u4f8b\u5316<\/strong>\uff0c\u53ea\u80fd\u88ab\u7ee7\u627f\u6216\u5b9e\u73b0\u3002<\/p>\n
      \u4e3a\u4ec0\u4e48\u9700\u8981\u62bd\u8c61\u7c7b\uff1f<\/h3>\n
      \u95ee\u9898<\/strong>\uff1a\u6709\u65f6\u5019\u6211\u4eec\u9700\u8981\u4e00\u4e2a\"\u6a21\u677f\"\u6216\"\u89c4\u8303\"\uff0c\u89c4\u5b9a\u5b50\u7c7b\u5fc5\u987b\u6709\u4ec0\u4e48\u65b9\u6cd5\uff0c\u4f46\u4e0d\u5173\u5fc3\u5177\u4f53\u600e\u4e48\u5b9e\u73b0\u3002<\/p>\n
      \/\/ \u274c \u666e\u901a\u7c7b\uff1a\u65b9\u6cd5\u5fc5\u987b\u5b9e\u73b0\nclass Animal {\n  void sound() {\n    \/\/ \u7236\u7c7b\u4e0d\u77e5\u9053\u5177\u4f53\u600e\u4e48\u53eb\uff0c\u4e0d\u77e5\u9053\u5b50\u7c7b\u60f3\u600e\u4e48\u53eb\n  }\n}\n\n\/\/ \u2705 \u62bd\u8c61\u7c7b\uff1a\u5b9a\u4e49\u89c4\u8303\uff0c\u5b50\u7c7b\u5fc5\u987b\u5b9e\u73b0\nabstract class Animal {\n  String name;\n\n  Animal(this.name);\n\n  \/\/ \u62bd\u8c61\u65b9\u6cd5\uff1a\u53ea\u6709\u58f0\u660e\uff0c\u6ca1\u6709\u65b9\u6cd5\u4f53\n  \/\/ \u5b50\u7c7b\u5fc5\u987b\u91cd\u5199\u8fd9\u4e2a\u65b9\u6cd5\n  void sound();\n}\n<\/code><\/pre>\n
      \u62bd\u8c61\u7c7b vs \u666e\u901a\u7c7b<\/h3>\n\n\n\n\n\n\n\n\n
      \u7279\u6027<\/th>\n\u62bd\u8c61\u7c7b<\/th>\n\u666e\u901a\u7c7b<\/th>\n<\/tr>\n<\/thead>\n
      \u5b9e\u4f8b\u5316<\/td>\n\u274c \u4e0d\u80fd\u76f4\u63a5\u521b\u5efa\u5bf9\u8c61<\/td>\n\u2705 \u53ef\u4ee5<\/td>\n<\/tr>\n
      \u62bd\u8c61\u65b9\u6cd5<\/td>\n\u53ef\u4ee5\u6709\uff0c\u5b50\u7c7b\u5fc5\u987b\u5b9e\u73b0<\/td>\n\u4e0d\u80fd\u6709<\/td>\n<\/tr>\n
      \u666e\u901a\u65b9\u6cd5<\/td>\n\u53ef\u4ee5\u6709\uff0c\u5b50\u7c7b\u76f4\u63a5\u7ee7\u627f\u4f7f\u7528<\/td>\n\u5fc5\u987b\u6709\u5b9e\u73b0<\/td>\n<\/tr>\n
      \u4f7f\u7528\u573a\u666f<\/td>\n\u5b9a\u4e49\"\u89c4\u8303\/\u6a21\u677f\"<\/td>\n\u76f4\u63a5\u521b\u5efa\u5bf9\u8c61\u4f7f\u7528<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \u793a\u4f8b\u5bf9\u6bd4<\/h3>\n
      \/\/ \u62bd\u8c61\u7c7b - \u5b9a\u4e49\u89c4\u8303\nabstract class Shape {\n  \/\/ \u62bd\u8c61\u65b9\u6cd5 - \u5b50\u7c7b\u5fc5\u987b\u5b9e\u73b0\n  double area();\n\n  \/\/ \u666e\u901a\u65b9\u6cd5 - \u5b50\u7c7b\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\n  void printInfo() {\n    print('\u9762\u79ef: ${area()}');\n  }\n}\n\nclass Circle extends Shape {\n  double radius;\n\n  Circle(this.radius);\n\n  @override\n  double area() {\n    return 3.14 * radius * radius;\n  }\n}\n\nclass Square extends Shape {\n  double side;\n\n  Square(this.side);\n\n  @override\n  double area() {\n    return side * side;\n  }\n}\n\nvoid main() {\n  var circle = Circle(5);\n  var square = Square(4);\n\n  circle.printInfo();  \/\/ \u9762\u79ef: 78.5\n  square.printInfo();  \/\/ \u9762\u79ef: 16\n\n  \/\/ var shape = Shape();  \/\/ \u274c \u9519\u8bef\uff01\u4e0d\u80fd\u5b9e\u4f8b\u5316\u62bd\u8c61\u7c7b\n}\n<\/code><\/pre>\n
      \n
      9. implements\uff08\u5b9e\u73b0\u63a5\u53e3\uff09<\/h2>\n
      \u4ec0\u4e48\u662f implements\uff1f<\/h3>\n
      implements<\/code> \u7528\u4e8e\u5b9e\u73b0<\/strong>\u4e00\u4e2a\u62bd\u8c61\u7c7b\u6216\u63a5\u53e3\uff0c\u5f3a\u5236\u5f53\u524d\u7c7b\u63d0\u4f9b\u67d0\u4e9b\u65b9\u6cd5\u7684\u5177\u4f53\u5b9e\u73b0\u3002<\/p>\n
      extends vs implements \u5bf9\u6bd4<\/h3>\n\n\n\n\n\n\n
      \u5173\u952e\u5b57<\/th>\n\u542b\u4e49<\/th>\n\u7279\u70b9<\/th>\n<\/tr>\n<\/thead>\n
      extends<\/code><\/td>\n\u7ee7\u627f<\/td>\n\u83b7\u5f97\u7236\u7c7b\u529f\u80fd\uff0c\u53ef\u9009\u91cd\u5199\uff0c\u53ef\u7528 super<\/code><\/td>\n<\/tr>\n
      implements<\/code><\/td>\n\u5b9e\u73b0<\/td>\n\u5fc5\u987b<\/strong>\u91cd\u5199\u6240\u6709\u62bd\u8c61\u65b9\u6cd5<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \u7528 extends \u7ee7\u627f<\/h3>\n
      class Animal {\n  void eat() => print('\u5403\u4e1c\u897f');\n}\n\nclass Dog extends Animal {\n  void bark() => print('\u6c6a\u6c6a\u53eb');\n}\n\nvoid main() {\n  var dog = Dog();\n  dog.eat();   \/\/ \u7ee7\u627f\u6765\u7684\u65b9\u6cd5\n  dog.bark();  \/\/ \u5b50\u7c7b\u81ea\u5df1\u7684\u65b9\u6cd5\n  \/\/ Dog \u81ea\u52a8\u6709 eat \u65b9\u6cd5\uff0c\u53ef\u4ee5\u76f4\u63a5\u7528\n}\n<\/code><\/pre>\n
      \u7528 implements \u5b9e\u73b0<\/h3>\n
      abstract class Flyable {\n  void fly();\n}\n\nclass Duck implements Flyable {\n  @override\n  void fly() {\n    print('\u9e2d\u5b50\u6251\u817e\u7fc5\u8180');\n  }\n}\n\nclass Plane implements Flyable {\n  @override\n  void fly() {\n    print('\u98de\u673a\u8d77\u98de');\n  }\n}\n\nvoid main() {\n  var duck = Duck();\n  var plane = Plane();\n\n  duck.fly();   \/\/ \u9e2d\u5b50\u6251\u817e\u7fc5\u8180\n  plane.fly();  \/\/ \u98de\u673a\u8d77\u98de\n\n  \/\/ \u5fc5\u987b\u91cd\u5199 fly \u65b9\u6cd5\uff0c\u5426\u5219\u7f16\u8bd1\u9519\u8bef\n}\n<\/code><\/pre>\n
      \u6838\u5fc3\u533a\u522b\uff1a\u7ee7\u627f vs \u5b9e\u73b0<\/h3>\n
      \/\/ ========== extends\uff08\u7ee7\u627f\u7236\u7c7b\uff09==========\nclass Parent {\n  void greet() => print('\u4f60\u597d');\n}\n\nclass Child extends Parent {\n  @override\n  void greet() => print('\u55e8');\n}\n\nvoid main() {\n  var child = Child();\n  child.greet();  \/\/ \u55e8\n  \/\/ Child \u81ea\u52a8\u6709 greet \u65b9\u6cd5\uff0c\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\n  \/\/ \u53ef\u4ee5\u9009\u62e9\u91cd\u5199\uff0c\u4e5f\u53ef\u4ee5\u4e0d\u91cd\u5199\n}\n\n\/\/ ========== implements\uff08\u5b9e\u73b0\u63a5\u53e3\uff09==========\nabstract class Greeter {\n  void greet();  \/\/ \u62bd\u8c61\u65b9\u6cd5\uff0c\u6ca1\u6709\u5b9e\u73b0\n}\n\nclass FriendlyGreeter implements Greeter {\n  @override\n  void greet() => print('\u4f60\u597d\u5440\uff01');\n}\n\nclass CasualGreeter implements Greeter {\n  @override\n  void greet() => print('\u55e8~');\n}\n\nvoid main() {\n  var friendly = FriendlyGreeter();\n  var casual = CasualGreeter();\n\n  friendly.greet();  \/\/ \u4f60\u597d\u5440\uff01\n  casual.greet();    \/\/ \u55e8~\n  \/\/ \u5fc5\u987b\u91cd\u5199 greet \u65b9\u6cd5\uff0c\u4e0d\u80fd\u7701\u7565\n}\n<\/code><\/pre>\n
      \u591a\u91cd\u5b9e\u73b0<\/h3>\n
      \u4e00\u4e2a\u7c7b\u53ef\u4ee5\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3\uff1a<\/p>\n
      abstract class Printer {\n  void print();\n}\n\nabstract class Scanner {\n  void scan();\n}\n\nclass AllInOnePrinter implements Printer, Scanner {\n  @override\n  void print() => print('\u6253\u5370\u4e2d...');\n\n  @override\n  void scan() => print('\u626b\u63cf\u4e2d...');\n}\n<\/code><\/pre>\n
      \n
      10. \u4e3a\u4ec0\u4e48\u6cdb\u578b\u524d\u9762\u52a0 abstract\uff1f<\/h2>\n
      abstract class Storage<T> {\n  void save(T item);\n  T? get(int id);\n  List<T> getAll();\n}\n<\/code><\/pre>\n
      \u539f\u56e0<\/h3>\n
        \n
      1. \u4e0d\u80fd\u76f4\u63a5\u5b9e\u4f8b\u5316<\/strong>\uff1aStorage<int>()<\/code> \u662f\u9519\u8bef\u7684<\/li>\n
      2. \u5b9a\u4e49\u89c4\u8303<\/strong>\uff1aStorage<T><\/code> \u5b9a\u4e49\u4e86\u4efb\u4f55\u5b58\u50a8\u7c7b\u5fc5\u987b\u6709\u7684\u65b9\u6cd5<\/li>\n
      3. \u5f3a\u5236\u5b9e\u73b0<\/strong>\uff1a\u4efb\u4f55 implements Storage<T><\/code> \u7684\u7c7b\u90fd\u5fc5\u987b\u5b9e\u73b0\u8fd9\u4e09\u4e2a\u65b9\u6cd5<\/li>\n<\/ol>\n
        \u4f7f\u7528\u573a\u666f<\/h3>\n
        \u5f53\u4f60\u9700\u8981\u5b9a\u4e49\u4e00\u4e2a\"\u89c4\u8303\"\uff0c\u8ba9\u591a\u4e2a\u7c7b\u90fd\u5fc5\u987b\u5b9e\u73b0\u67d0\u4e9b\u65b9\u6cd5\u65f6\uff1a<\/p>\n
        abstract class Repository<T> {\n  Future<T?> getById(int id);\n  Future<List<T>> getAll();\n  Future<void> save(T item);\n  Future<void> delete(int id);\n}\n\n\/\/ \u5b9e\u73b0\u63a5\u53e3\nclass UserRepository implements Repository<User> {\n  \/\/ \u5fc5\u987b\u5b9e\u73b0\u6240\u6709 4 \u4e2a\u65b9\u6cd5\n  @override\n  Future<User?> getById(int id) async { ... }\n\n  @override\n  Future<List<User>> getAll() async { ... }\n\n  @override\n  Future<void> save(User item) async { ... }\n\n  @override\n  Future<void> delete(int id) async { ... }\n}\n\nclass ProductRepository implements Repository<Product> {\n  \/\/ \u4e5f\u5fc5\u987b\u5b9e\u73b0\u6240\u6709 4 \u4e2a\u65b9\u6cd5\n  @override\n  Future<Product?> getById(int id) async { ... }\n\n  @override\n  Future<List<Product>> getAll() async { ... }\n\n  @override\n  Future<void> save(Product item) async { ... }\n\n  @override\n  Future<void> delete(int id) async { ... }\n}\n<\/code><\/pre>\n
        \n
        11. \u5feb\u901f\u8bb0\u5fc6<\/h2>\n\n\n\n\n\n\n\n\n
        \u6982\u5ff5<\/th>\n\u5173\u952e\u5b57<\/th>\n\u7279\u70b9<\/th>\n<\/tr>\n<\/thead>\n
        \u62bd\u8c61\u7c7b<\/td>\nabstract class<\/code><\/td>\n\u4e0d\u80fd\u5b9e\u4f8b\u5316\uff0c\u5b9a\u4e49\u89c4\u8303<\/td>\n<\/tr>\n
        \u62bd\u8c61\u65b9\u6cd5<\/td>\nvoid method();<\/code><\/td>\n\u53ea\u6709\u58f0\u660e\u6ca1\u6709\u5b9e\u73b0\uff0c\u5b50\u7c7b\u5fc5\u987b\u91cd\u5199<\/td>\n<\/tr>\n
        \u5b9e\u73b0\u63a5\u53e3<\/td>\nimplements<\/code><\/td>\n\u5fc5\u987b\u91cd\u5199\u6240\u6709\u62bd\u8c61\u65b9\u6cd5<\/td>\n<\/tr>\n
        \u7ee7\u627f\u7236\u7c7b<\/td>\nextends<\/code><\/td>\n\u83b7\u5f97\u529f\u80fd\uff0c\u53ef\u9009\u91cd\u5199<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
        \n  \ud83c\udfaf \u4ec0\u4e48\u65f6\u5019\u7528 abstract\uff1f<\/strong>
        \n  - \u9700\u8981\u5b9a\u4e49\"\u6a21\u677f\/\u89c4\u8303\"\u65f6
        \n  - \u4e0d\u9700\u8981\u76f4\u63a5\u521b\u5efa\u5bf9\u8c61\u65f6<\/p>\n
          \ud83c\udfaf \u4ec0\u4e48\u65f6\u5019\u7528 implements\uff1f<\/strong>
        \n  - \u9700\u8981\u5f3a\u5236\u67d0\u4e2a\u7c7b\u5b9e\u73b0\u67d0\u4e9b\u65b9\u6cd5\u65f6
        \n  - \u5b9a\u4e49\"\u63a5\u53e3\"\uff08Dart \u6ca1\u6709 interface \u5173\u952e\u5b57\uff0c\u7528 abstract class \u4ee3\u66ff\uff09<\/p>\n
          \ud83c\udfaf extends vs implements<\/strong>
        \n  - extends<\/code>\uff1a\u7ee7\u627f\u7236\u7c7b\uff0c\u83b7\u5f97\u529f\u80fd\uff0c\u53ef\u7528 super<\/code>
        \n  - implements<\/code>\uff1a\u5b9e\u73b0\u63a5\u53e3\uff0c\u5fc5\u987b\u91cd\u5199\u6240\u6709\u65b9\u6cd5\n<\/p><\/blockquote>\n
        \n","protected":false},"excerpt":{"rendered":"
        Dart \u7c7b\u4e0e\u9762\u5411\u5bf9\u8c61 1. \u7c7b\u7684\u57fa\u672c\u5199\u6cd5 \u7c7b = \u5c5e\u6027\uff08\u6570\u636e\uff09+ \u6784\u9020\u51fd\u6570 + \u65b9\u6cd5\uff08\u884c\u4e3a\uff09 class Person { \/\/ …<\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-117","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/posts\/117","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/comments?post=117"}],"version-history":[{"count":3,"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/posts\/117\/revisions"}],"predecessor-version":[{"id":120,"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/posts\/117\/revisions\/120"}],"wp:attachment":[{"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/media?parent=117"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/categories?post=117"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tachyoncat.top\/index.php\/wp-json\/wp\/v2\/tags?post=117"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}