我想保存状态中的更改，即使页面被重新加载。我已经在console.log中检查了我的oldState常量，它可以工作。但是我的用户界面不显示本地存储中的状态。我该如何在preloadedState中使用我的oldState常量？

const saveState = state => {
  try {
    const serialisedState = JSON.stringify(state)
    window.localStorage.setItem('appState', serialisedState)
  } catch (err) {
    // error message
  }
}

const loadState = () => {
  try {
    const serialisedState = window.localStorage.getItem('appState')
    console.log(serialisedState)
    if (!serialisedState) return undefined
  } catch (err) {
    // error message
    return undefined
  }
}

const oldState = loadState()

export const store = configureStore({
  reducer: {
    products,
    filters,
    product,
    cart,
  },
  preloadedState: oldState,
})

store.subscribe(() => {
  saveState(store.getState())
})