使用 useEffect 努力调试 Expo 上的无效挂钩调用

Question

When selecting an address from Places Autocomplete (ie onPress), I am calling a function to try and return the value of geocodeAsync from Expo location. I am however getting an invalid hook call when this function is being called, any advice would be lovely.

function getArray(data) {
    React.useEffect(() => {
        async function getPromise() {
            const res = await geocodeAsync(data); // type: Promise<Interface>
            setCoordinates(res);
        }
        void getPromise();
    }, [])
    const [coordinates2, setCoordinates] = React.useState<LocationGeocodedLocation[]>()
    return coordinates2

}

Answer 1

Your outer function needs to have the prefix use so it can be parsed as a hook by React (ie useGetArray ). You should also define your state before your useEffect so there's no risk of your set function being called before it's defined. See https://reactjs.org/docs/hooks-custom.html .

Also, consider turning on the React lint rules so you aren't missing dependencies in your useEffect.