一、Flutter 主动跟iOS交互

比如flutter端向iOS原生请求获取当前手机连接wifi名字：

flutter 部分代码：

final _channel = MethodChannel("ios_channel");
_channel.invokeMethod('get_wifi_name');

如果有参数传输：

  final _channel = MethodChannel("ios_channel");
var map = {
        '': '',
      };
_channel.invokeMethod('get_wifi_name',map);

iOS部分代码：

@interface AppDelegate ()
@property (nonatomic,strong)FlutterViewController *flutterViewController;
@property (nonatomic, strong) FlutterEventChannel *eventChannel;
@end
@implementation AppDelegate

- (BOOL)application:(UIApplication *)application
    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.flutterViewController = [[FlutterViewController alloc]init];
self.window.rootViewController = self.flutterViewController;

FlutterMethodChannel *notifationChannel = [FlutterMethodChannel methodChannelWithName:@"ios_channel" binaryMessenger:(NSObject<FlutterBinaryMessenger> *)self.flutterViewController];
 __weak typeof (self)weakSelf = self;
        [notifationChannel setMethodCallHandler:^(FlutterMethodCall * _Nonnull call, FlutterResult  _Nonnull result) {
            if ([@"get_wifi_name" isEqualToString:call.method]) {
                //如果有参数 call.arguments即从flutter端传过来的参数 map
               //NSDictionary *dic = call.arguments;
                NSString *wifiName =  [weakSelf getWifi];
                result(wifiName);
            }
        }];
[GeneratedPluginRegistrant registerWithRegistry:self];
    
  // Override point for customization after application launch.
  return [super application:application didFinishLaunchingWithOptions:launchOptions];
}

- (NSString *)getWifi{
    NSString *ssid = @"";
    CFArrayRef myArray = CNCopySupportedInterfaces();
    NSLog(@"myArray:%@",myArray);
    if (myArray != nil) {
        CFDictionaryRef myDict = CNCopyCurrentNetworkInfo((CFStringRef)CFArrayGetValueAtIndex(myArray, 0));
        if (myDict != nil) {
            NSDictionary *dict = (NSDictionary *)CFBridgingRelease(myDict);
            ssid = [dict valueForKey:@"SSID"];
            NSLog(@"%@",dict);
        }
    }
    return ssid;
}

二、iOS主动跟Flutter交互

比如iOS端获取监测当前手机连接wifi名字变化，同时传输flutter端

iOS 端代码：

@interface AppDelegate ()<FlutterStreamHandler>

@property (nonatomic, strong) FlutterEventChannel *eventChannel;
@property (nonatomic, copy) FlutterEventSink sink;
@end
@implementation AppDelegate

- (BOOL)application:(UIApplication *)application
    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.flutterViewController = [[FlutterViewController alloc]init];
self.window.rootViewController = self.flutterViewController;
self.eventChannel = [FlutterEventChannel eventChannelWithName:@"ios_event_channel" binaryMessenger:(NSObject<FlutterBinaryMessenger> *)self.flutterViewController];
 [self.eventChannel setStreamHandler:self];

[self listeningWIFIChange];
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(updateWifi) name:@"updateWifi" object:nil];

[GeneratedPluginRegistrant registerWithRegistry:self];
    
  // Override point for customization after application launch.
  return [super application:application didFinishLaunchingWithOptions:launchOptions];
}

- (void)updateWifi{
    NSString *wifiName = [self getWifi];
    NSLog(@"ios ---- 网络变化-----wifiName:%@",wifiName);
    NSLog(@"%@",self.sink);
//通过该方法传值给flutter
    if (self.sink != nil){
   //当有多个值返回给flutter的时候，比如获取wifi、获取手机版本号等等，可以给dic添加个参数key区分参数，方便flutter接收的时候区分
     NSDictionary *dic = {@"key":@"wifi",@"name":wifiName};
        self.sink(dic);
    }
}

//监听网络变化
- (void)listeningWIFIChange{

    CFNotificationCenterAddObserver(CFNotificationCenterGetDarwinNotifyCenter(), NULL,onNotifyCallback, CFSTR("com.apple.system.config.network_change"), NULL,CFNotificationSuspensionBehaviorDeliverImmediately);
}

static void onNotifyCallback(CFNotificationCenterRef center, void *observer, CFStringRef name, const void *object, CFDictionaryRef userInfo){
    NSString* notifyName = (__bridge NSString *) name;
    if ([notifyName isEqualToString:@"com.apple.system.config.network_change"]) {
        NSLog(@"======网络变化");
        [[NSNotificationCenter defaultCenter] postNotificationName:@"updateWifi" object:nil];
    } else {
        NSLog(@"intercepted %@", notifyName);
    }
}

#pragma mark - <FlutterStreamHandler>

// 这个onListen是Flutter端开始监听这个channel时的回调，第二个参数 EventSink是用来传数据的载体
- (FlutterError* _Nullable)onListenWithArguments:(id _Nullable)arguments
                                       eventSink:(FlutterEventSink)events {
    NSLog(@"onListenWithArguments");
    self.sink = events;
    return nil;
}

- (FlutterError* _Nullable)onCancelWithArguments:(id _Nullable)arguments {
    NSLog(@"onCancelWithArguments");
    return  nil;
}

Flutter 端代码：

EventChannel _eventChannel = const EventChannel("ios_event_channel");
_eventChannel
        .receiveBroadcastStream("init")
        .listen(_onEvent, onError: _onError);
void _onEvent(Object event) {
    Map map = event;
    //此处为从iOS端接收到的数据
    if (map['key'] == 'wifi'){
      print("wifi名字:${map['name']}");
    }
  }

  void _onError(Object error){
    print("--------------error:${error}");
  }

可以在flutter端写一个单例专门处理关于数据处理的，以下发一下flutter端完整的代码：

单例代码：

class IosUtils {
  static final IosUtils _managerIos = IosUtils.internal();

  StreamController<dynamic> deviceController;
  Stream deviceStream;

  EventChannel _eventChannel = const EventChannel("ios_event_channel");
  final _channel = MethodChannel("ios_channel");

  factory IosUtils.getInstance() {
    return _managerIos;
  }
  IosUtils.internal() {
    deviceController = StreamController();
    deviceStream = deviceController.stream.asBroadcastStream();

    _eventChannel
        .receiveBroadcastStream("init")
        .listen(_onEvent, onError: _onError);
  }

  void _onEvent(Object event) {
    Map map = event;
    print("--------------map:${map}");
   //添加监听
    deviceController.sink.add(map);
  }

  void _onError(Object error){
    print("--------------error:${error}");
  }

  void getWifiName(){
 _channel.invokeMethod('get_wifi_name');
  }
}

flutter页面处理代码

@override
  void initState() {
    super.initState();
    if (Platform.isIOS){
      IosUtils.getInstance().getWifiName();
      IosUtils.internal().deviceStream.listen((data){
        String key = data['key'];
        if (map['key'] == 'wifi'){
         print("wifi名字:${map['name']}");
         }
      });
    }
  }