stock-web/src/store/index.ts

import { InjectionKey } from 'vue'
import { createStore, useStore as baseUseStore, Store } from 'vuex'

// 为 store state 声明类型
export interface State {
    num: number
}

// 定义 injection key
export const key: InjectionKey<Store<State>> = Symbol()

export const store = createStore<State>({
  state: {
    num: 888
  },
  mutations: {
    setNum (state: State, num: number) {
      state.num = num
    }
  },
  getters: {
    getNum (state: State) {
      return state.num
    }
  }
})

// 定义自己的 `useStore` 组合式函数
export function useStore () {
  return baseUseStore(key)
}