【语法对比】(Block、枚举、通知)

1.Block

OC

A 类
1.声明typedef void(^JDKitOpenChatCallback)(NSDictionary *chatInfo);
@property (nonatomic, copy) JDKitOpenChatCallback openChatCallback;

2.实现
if (self.openChatCallback) {
   self.openChatCallback(xxx);
}

B 类
3.回调
[JDKitManager shareInstance].openChatCallback = ^(NSDictionary *chatInfo) { ///回调
    NSLog(chatInfo);
};

Swift

A 类
1.声明
var onTap: (() -> ())?

2.实现
onTap?()

B 类
3.回调
xxx.onTap = {
     print("回调")
}

Flutter

A 类
1.声明
VoidCallback onTap;
XXX({Key key, @required this.onTap}) : super(key: key);

2.调用
widget.onTap();

B 类
3.回调
XXX(onTap:(){
  print("回调");
  setState(() {});
},),

2.枚举

OC

typedef NS_ENUM(NSUInteger, JDStyle) {
    JDStyleNormal,
    JDStyleCancel,
};

@property(nonatomic, readonly, assign) JDStyle style;

Swift

用法一：
enum JDType {
    case myGroup
    case myAttention
    var name: String {
        switch self {
        case .myGroup:
            return "我的群组"
        case .myAttention:
            return "我的关注"
        }
    }
}

let types: [JDType] = [.myGroup, .myAttention,]
        
for (index , item) in types.enumerated() {
    print("下标\(index) 值为\(item)")
}

用法二：
public enum RoleStatusType: Int {
    case outsourced = 1
    case regularEmployee
    case trainee
    case officialAccount
}
    
public var roleStatusType: RoleStatusType {
    return RoleStatusType(rawValue: Int(empStatus)) ?? .regularEmployee
}

guard member.roleStatusType == .officialAccount else { return nil }

Flutter

enum Season {
  spring,
  summer,
  autumn,
  winter
}

void testDart(){
  var currentSeason = Season.summer;
  switch (currentSeason) {
    case Season.spring:
      print('1-3月');
      break;
    case Season.summer:
      print('4-6月');
      break;
    case Season.autumn:
      print('7-9月');
      break;
    case Season.winter:
      print('10-12月');
      break;
  }
}

2.通知

OC

//订阅事件
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(notificationAction) name:@"事件名称" object:nil];

- (void)notificationAction:(NSNotification *)notification{  
	//这里我们拿到Children对象进行操作  
	Children *children = notification.object;  
	NSLog(@"触发通知");  
}  

//触发事件
[[NSNotificationCenter defaultCenter] postNotificationName:@"事件名称" object:self];

//移除事件
- (void)dealloc {
	1.移除指定的通知，不然会造成内存泄露  
	[[NSNotificationCenter defaultCenter] removeObserver:self name:@"事件名称" object:nil]; 
    2.下面的方法是可以移除Children中所有通知
	[[NSNotificationCenter defaultCenter] removeObserver:self];
}

Swift

///订阅事件
NotificationCenter.default.addObserver(self, selector: #selector(notificationAction), name: NSNotification.Name(rawValue:"事件名称"), object: nil)

///实现方法
@objc func notificationAction(nofi : Notification){
    let str = nofi.userInfo!["content"]
    print(String(describing: str!) + "this notifi")
}

///触发事件
NotificationCenter.default.post(name: NSNotification.Name("事件名称"), object: self, userInfo: ["content":"您好"])

///移除事件
deinit {
    NotificationCenter.default.removeObserver(self)
}

Flutter

class EventBus {
  /// 私有构造函数
  EventBus._internal();

  /// 保存单例
  static EventBus _singleton = new EventBus._internal();

  /// 工厂构造函数
  factory EventBus() => _singleton;

  /// 保存事件订阅者队列，key:事件名(id)，value: 对应事件的订阅者队列
  var _eMap = new Map<Object, List<EventCallback>>();

  /// 添加订阅者
  void on(eventName, EventCallback f) {
    if (eventName == null || f == null) return;
    _eMap[eventName] ??= new List<EventCallback>();
    _eMap[eventName].add(f);
  }

  /// 移除订阅者
  void off(eventName, [EventCallback f]) {
    var list = _eMap[eventName];
    if (eventName == null || list == null) return;
    if (f == null) {
      _eMap[eventName] = null;
    } else {
      list.remove(f);
    }
  }

  /// 触发事件，事件触发后该事件所有订阅者会被调用
  void send(eventName, [arg]) {
    var list = _eMap[eventName];
    if (list == null) return;
    int len = list.length - 1;
    //反向遍历，防止订阅者在回调中移除自身带来的下标错位
    for (var i = len; i > -1; --i) {
      list[i](arg);
    }
  }
}

//订阅事件
EventBus().on("事件名称", (arg) {
});

//触发事件
EventBus().send("事件名称",arg);

//移除事件
void dispose() {
	// TODO: implement dispose
    super.dispose();
    EventBus().off("事件名称");
}