reactjs - 在应用程序中多次使用 useSelector react redux

Question

您好，我在我的应用程序中多次使用选择器。我可以编写一次代码然后导入选择器吗？我想写一个自定义钩子(Hook)，但我认为这是没有必要的。这是我的选择器:

const county = useSelector((state)=>{
    const id = state.user.id
    const name = state.user.name
    return state.users.filter((user) => user.name === name)[0].county
})

如果我有这样的东西就好了:

import {countySelector} from 'selectors'
const county = useSelector(countySelector)

Answer 1

可以在useSelector中传递箭头函数

export const countySelector = state => {
    const id = state.user.id;
    const name = state.user.name;
    return state.users.find(user => user.name === name).county;
};

// Usage
import { countySelector } from 'selectors';
const county = useSelector(countySelector);

或者创建自定义钩子(Hook)

const useCounty = () => {
    return useSelector(state => {
        const id = state.user.id;
        const name = state.user.name;
        return state.users.find(user => user.name === name).county;
    });
};

export default useCounty;

// Usage
import useCounty from 'useCounty';
const county = useCounty();