在 Swift 中实现 RCTEventEmitter 但未设置桥接的接收异常 [英] Implement RCTEventEmitter in Swift but receive exception for bridge is not set

问题描述

我正在尝试在 Swift 中为 React Native 实现一个事件发射器，以便我可以在我的一些本机模块中重用它.但是，当我从 iOS 本地发送事件时，收到以下错误

I am trying to implement an event emitter for React Native in Swift so that I can reuse it across some of my native modules. However, when I send event natively from iOS, I received the following error

Bridge is not set. This is probably because you've explicitly synthesized the bridge in MyEventEmitter, even though it's inherited from RCTEventEmitter.

/// MyEventEmitter.m
#import <Foundation/Foundation.h>
#import <React/RCTBridgeModule.h>
#import <React/RCTEventEmitter.h>

@interface RCT_EXTERN_MODULE(MyEventEmitter, RCTEventEmitter)

RCT_EXTERN_METHOD(supportedEvents)

@end

在 Swift 中的实现:

Implementation in Swift:

import Foundation

@objc(MyEventEmitter)
class MyEventEmitter: RCTEventEmitter {

    public static let shared = MyEventEmitter()

    override func supportedEvents() -> [String]! {
        return [
            ... // my event list
        ]
    }
}

在我的原生 swift 代码中，我通过

In my native swift code, I initialized the emiter by

private let eventEmitter: MyEventEmitter = .shared

// send event
self.eventEmitter.sendEvent(withName: "someEvent", body: nil)

我还将 和 放在我的桥接头中.

I also put <React/RCTBridgeModule.h> and <React/RCTEventEmitter.h> inside my bridging header.

我在这里做错了什么?

推荐答案

我发现的问题是你不能在 public static let shared = MyEventEmitter() 中自己实例化 MyEventEmitter

The problem I found was that you must not instantiate the MyEventEmitter yourself aka in public static let shared = MyEventEmitter()

你应该重写 init 方法并将 self 分配给 shared

You should rather override the init method and assign self to shared

import Foundation

@objc(MyEventEmitter)
class MyEventEmitter: RCTEventEmitter {

    public static var shared:MyEventEmitter?

    override init() {
        super.init()
        MyEventEmitter.shared = self
    }

    override func supportedEvents() -> [String]! {
        return [
            ... // my event list
        ]
    }
}

这是因为 RN 会自己实例化对象并分配桥，而当你自己做时，桥不会被分配.

This is because RN will instantiate the object itself already and assign the bridge, whereas when you are doing it yourself the bridge will not be assigned.

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