javascript - React native和MobX:如何创建全局商店？

我目前正在尝试实现一个mobx存储，可以像这样从任何地方调用它:

import {userStore} from '../UserStore.js';

在文件末尾，我的导出功能如下所示:

const userStore = new UserStore();
export {userStore};

据我了解，每次调用import功能时，都会重新创建对象，导入UserStore的多个文件不会共享同一变量。

但是，我希望每个导入UserStore的文件都导入具有完全相同变量的相同对象。我该如何实现？我不太确定该如何实现，因此不胜感激:)

完整的代码(用于UserStore.js声明)(如果有帮助)如下(在export语句的最底部)

import {observable, computed, action} from 'mobx';
import {ObservableMap, toJS} from 'mobx';
import {Fb} from './firebase.js';

class UserStore {

  /** GPS */
  @observable usrLng = 0.0;
  @observable usrLat = 0.0;
  @observable watchID = null;

  @action
  watchCurLocation() {
    this.watchID = navigator.geolocation.watchPosition((position) => {
      console.log("Recording GPS data from within the Store!!");
      this.usrLat = parseFloat(position.coords.latitude);
      this.usrLng = parseFloat(position.coords.longitude);
      }, (error) => console.log(JSON.stringify(error)), {
        enableHighAccuracy: true,
        timeout: 2000,
        maximumAge: 1000
      });
  }

  @action
  clearWatch() {
    navigator.geolocation.clearWatch(this.watchID);
  }
  /*/ GPS */

  /** BIKE BOOKING  */
  @observable interestBikeNo = -1;
  @observable bookedBikeNo = -1;

  @action
  setInterestBikeNo(bn) {
    this.interestBikeNo = bn;
  }

}

const userStore = new UserStore();
export {userStore};

最佳答案

您只需要UserStore类的单例实例

样本演示

let localInstance = null;

export class Apple {
  static newInstance() {
    if (! localInstance)
      localInstance = new Apple();
    return localInstance;
  }
}

// usage

import {Apple} from './apple';
const instance = Apple. newInstance();

您可以使用一个简单的函数

import {observable, computed, action} from 'mobx';
import {ObservableMap, toJS} from 'mobx';
import {Fb} from './firebase.js';

class UserStore {
  // omitted
}

let userStore;
export function getUserstore() {
  if (!userStore)
    userStore = new UserStore();
  return userStore;
};

代码中的某个地方

// instead of
import {userStore} from './someUserStoreModule';

// use
import {getUserstore} from './someUserStoreModule';
const userStore = getUserstore();