Reactnative 将 async 和 await 与 export const 一起使用

发布于06月12日

我做不到...上面写着:"等待"是一个保留的词.是的，当然是...我想用它:)

怎么了？

export const loginWithToken = async () => {
  return dispatch => {
    dispatch({type: SESSION_LOGIN_IN_PROGRESS, payload: true})
    let storedData = await ReadFromLocalDB('user')
    console.log(storedData)
    if (!storedData) {
        invalidToken(null, dispatch)
    }
    else {
        storedData = JSON.parse(storedData)
        SessionLoginWithToken(storedData.session.token).then(res => {
            console.log(res)
            loginSuccessfully(res, dispatch, true)
        })
    }
  }
}

我的ReadFromLocalDB函数如下所示:

export const ReadFromLocalDB = async (key) => {
   return AsyncStorage.getItem(key)
}

它回报了一个promise

推荐答案

我相信return dispatch => {...}也应该是async.现在，只有顶级函数是async，而不是嵌套函数.

// This function is async
export const loginWithToken = async () => {
  // This one is not though which means it can't use await inside
  // return dispatch => {

  // Instead it should likely be:
  return async dispatch => {
    dispatch({type: SESSION_LOGIN_IN_PROGRESS, payload: true})
    let storedData = await ReadFromLocalDB('user')
    console.log(storedData)
    if (!storedData) {
        invalidToken(null, dispatch)
    }
    else {
        storedData = JSON.parse(storedData)
        SessionLoginWithToken(storedData.session.token).then(res => {
            console.log(res)
            loginSuccessfully(res, dispatch, true)
        })
    }
  }
}