在本机ios中侦听事件

Question

我不能为我的生活得到一个事件,从iOS本机跨桥到适当的原生JS上下文正确发送.在Objective-C方面,我希望有一个模块可以轻松地在整个桥上发送事件.我已经调用了这个类EventEmitter,它的定义如下:

// EventEmitter.h

#import "RCTBridge.h"
#import "RCTEventDispatcher.h"

@interface EventEmitter : NSObject<RCTBridgeModule>

  - (void)emitEvent:(NSString *) eventName withData:(id) eventData;

@end

和实施:

// EventEmitter.m

#import "EventEmitter.h"

@implementation EventEmitter

  RCT_EXPORT_MODULE();

  @synthesize bridge = _bridge;

  - (void)emitEvent:(NSString *) eventName withData:(id) eventData
  {
    NSLog( @"emitting %@ with data %@", eventName, [eventData description] );
    [[_bridge eventDispatcher] sendDeviceEventWithName:eventName body:eventData];
    [[_bridge eventDispatcher] sendAppEventWithName:eventName body:eventData];
  }

@end

我正在使用sendDeviceEvent和sendAppEvent,因为我无法工作.

对事物的JS一边,我在注册我的模块之一(这样我才知道是发出该事件之前会发生的事件订阅)的全局命名空间来接收这些事件.我这样注册:

console.log( 'ADDING EVENT LISTENERS' );
NativeAppEventEmitter.addListener( 'blah', test => console.log( 'TEST1', test ) );
DeviceEventEmitter.addListener( 'blah', test => console.log( 'TEST2', test ) );

在我的日志语句中,我得到以下内容:

2016-03-19 12:26:42.501 [trace][tid:com.facebook.React.JavaScript] ADDING EVENT LISTENERS
2016-03-19 12:26:43.613 [name redacted][348:38737] emitting blah with data [data redacted]

所以我可以告诉我发送了一个应用程序事件和一个带有标签blah的设备事件,我已注册用DeviceEventEmitter和NativeAppEventEmitters监听blah事件,但我没有在监听器中回调.

我究竟做错了什么？？谢谢阅读!

Answer 1

我试过调度事件，bridge当您EventEmitter使用手动创建新实例时，似乎未初始化[EventEmitter alloc] init]

您应该让react-native创建实例。我检查了本机组件，它们正在使用-(void)setBridge:(RCTBridge *)bridge方法进行初始化工作。请查看RCTLinkingManager示例。它NSNotificationCenter用于处理事件。

// registering for RCTOpenURLNotification evet when the module is initialised with a bridge
- (void)setBridge:(RCTBridge *)bridge
{
  _bridge = bridge;

  [[NSNotificationCenter defaultCenter] addObserver:self
                                           selector:@selector(handleOpenURLNotification:)
                                               name:RCTOpenURLNotification
                                             object:nil];
}

// emitting openURL event to javascript
- (void)handleOpenURLNotification:(NSNotification *)notification
{
  [_bridge.eventDispatcher sendDeviceEventWithName:@"openURL"
                                              body:notification.userInfo];
}

// creating RCTOpenURLNotification event to invoke handleOpenURLNotification method
+ (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)URL
  sourceApplication:(NSString *)sourceApplication
         annotation:(id)annotation
{
  NSDictionary<NSString *, id> *payload = @{@"url": URL.absoluteString};
  [[NSNotificationCenter defaultCenter] postNotificationName:RCTOpenURLNotification
                                                      object:self
                                                    userInfo:payload];
  return YES;
}

Answer 2

你可以用 NativeEventEmitter

// register eventEmitter
    const {NGListener} = NativeModules; // NSListener is my class
    this.eventEmitter = new NativeEventEmitter(NativeModules.NGListener);   
    this.eventEmitter.addListener('CancelEvent', (data) => {
      console.log(data);
    })

在ObjectiveC中,您可以创建

    #import <RCTViewManager.h>
    #import <RCTEventEmitter.h>
    @interface NGListener: RCTEventEmitter <RCTBridgeModule>
    @end

    @implementation NGListener

    RCT_EXPORT_MODULE();

    - (NSArray<NSString*> *)supportedEvents {
        return @[@"CancelEvent", @"OKEvent"];
    }
    // And you sent event you want from objectC to react-native
    [self sendEventWithName:@"CancelEvent" body:@"Tap`enter code here` on Cancel button      from Objc"];

我编写了示例示例来处理从react-native到objectivec和对面的事件. https://github.com/lengocgiang/event-listener 希望这个帮助!!