为什么我不能让这个调度功能运行？

Question

我不知道为什么我不能让这个调度函数到达console.log(3) 和console.log(4)，我试图从成功函数内部移动调度，但它再次不起作用。

export const getDistance = (storeLocation) => {
    console.log('called1')
    const options = {
        enableHighAccuracy: true,
        timeout: 5000,
        maximumAge: 0,
    };

    const success = (pos) => {
        console.log('called2')

        return dispatch => {
            console.log('called3')
            dispatch({ type: FETCHING_GEO_DATA })

            axios
                .get(
                    `${process.env.REACT_APP_GEO_BASE_URL}?waypoint.0=${pos.coords.latitude},${pos.coords.longitude}&waypoint.1=${storeLocation}&du=mi&key=${process.env.REACT_APP_GEO_KEY}`
                )
                .then((res) => {
                    console.log('called4')

                    dispatch({
                        type: FETCHING_GEO_DATA_SUCCESS,
                        payload: res.data.resourceSets[0].resources[0].travelDistance.toFixed(1)
                    })
                })
                .catch((err) => {
                    console.log('called4')
                    dispatch({
                        type: FETCHING_GEO_DATA_FAILURE,
                        payload: err
                    })
                });
        }

    }

    const error = (err) => {
        console.warn(`ERROR(${err.code}): ${err.message}`);
    }

    return window.navigator.geolocation ? navigator.geolocation.getCurrentPosition(success, error, options) : null
};

Answer 1

你没有调用return inside success的内部函数。

试试这个：

 return window.navigator.geolocation ?
 navigator.geolocation.getCurrentPosition(()=>success(pos)(), error, options) 
 : null

如果你想在不传递参数的情况下保留你的成功函数，你可能会立即调用调度内部函数 (IIEF)

  const success = (pos) => {
    console.log('called2')

    ((dispatch) => {
      console.log('called3')
      dispatch({
        type: FETCHING_GEO_DATA
      })

      axios
        .get(
          `${process.env.REACT_APP_GEO_BASE_URL}?waypoint.0=${pos.coords.latitude},${pos.coords.longitude}&waypoint.1=${storeLocation}&du=mi&key=${process.env.REACT_APP_GEO_KEY}`
        )
        .then((res) => {
          console.log('called4')

          dispatch({
            type: FETCHING_GEO_DATA_SUCCESS,
            payload: res.data.resourceSets[0].resources[0].travelDistance.toFixed(1)
          })
        })
        .catch((err) => {
          console.log('called4')
          dispatch({
            type: FETCHING_GEO_DATA_FAILURE,
            payload: err
          })
        });
    })()
  }