Question

我正在尝试使用RxJS过滤React Native中的本地事件。我正在使用react-native-ble-manager公开一个EventEmitter。基本上，没有 RxJS我正在执行以下操作（此处仅显示相关代码）：

import React from 'react';
import RX from 'reactxp';
import { AppState, Platform, NativeModules, NativeEventEmitter, EmitterSubscription, PermissionsAndroid, ListView } from 'react-native';
import BleManager, { Peripheral } from 'react-native-ble-manager';

const BleManagerModule = NativeModules.BleManager;
const bleManagerEmitter = new NativeEventEmitter(BleManagerModule);

export class App extends RX.Component<IAppProps, IAppState> {

      private handlerDiscover!: EmitterSubscription;
      private  handlerStop!:EmitterSubscription;
      private  handlerDisconnect!:EmitterSubscription;
      private  handlerUpdate!:EmitterSubscription;

      componentDidMount() {
        AppState.addEventListener('change', this.handleAppStateChange);

        BleManager.start({ showAlert: false });

        this.handlerDiscover = bleManagerEmitter.addListener('BleManagerDiscoverPeripheral', this.handleDiscoverPeripheral);
        this.handlerStop = bleManagerEmitter.addListener('BleManagerStopScan', this.handleStopScan);
        this.handlerDisconnect = bleManagerEmitter.addListener('BleManagerDisconnectPeripheral', this.handleDisconnectedPeripheral);
        this.handlerUpdate = bleManagerEmitter.addListener('BleManagerDidUpdateValueForCharacteristic', this.handleUpdateValueForCharacteristic);
      }
      componentWillUnmount() {
        this.handlerDiscover.remove();
        this.handlerStop.remove();
        this.handlerDisconnect.remove();

      }
      handleUpdateValueForCharacteristic = (data:any) => {
        console.log('Received data from ' + data.peripheral + ' characteristic ' + data.characteristic + ' length ' + data.value.length + ' values ' + data.value);
       }
    }

一旦我连接到BLE外设并开始数据检索，便会使用数据调用箭头函数handleUpdateValueForCharacteristic。很好。

现在，我想使用RxJS来过滤事件，因为我每秒最多可以接收200个事件，但是我只对其中的1/4感兴趣。

我只是无法用心fromEventPattern。

到目前为止，我已经尝试过以下操作：

在类中添加了一些处理函数：

  private addHandler:Function = (handler:NodeEventHandler):any => {
    this.handlerUpdate = bleManagerEmitter.addListener('BleManagerDidUpdateValueForCharacteristic', handler);
    return this.handlerUpdate;
  }

  private removeHandler:Function = (handler:EmitterSubscription, _signal?:any) => {
    handler.remove();
  }

在componentDidMount（）中：

this.emitter = fromEventPattern<any>(this.addHandler(this.handleUpdateValueForCharacteristic), this.removeHandler(this.handlerUpdate));
this.emitter.subscribe(...);

但是订阅失败，出现以下错误：

addHandler不是函数。

RxJS fromEventPattern与React Native事件

0 个答案: