有了这一行代码，你可以在React Hook和React Class Component的任何地方使用它。

https://www.hunterisgod.com/?city=Leipzig

let city = (new URLSearchParams(window.location.search)).get("city")

你可以创建一个简单的钩子来从当前位置提取搜索参数:

import React from 'react';
import { useLocation } from 'react-router-dom';

export function useSearchParams<ParamNames extends string[]>(...parameterNames: ParamNames): Record<ParamNames[number], string | null> {
    const { search } = useLocation();
    return React.useMemo(() => { // recalculate only when 'search' or arguments changed
        const searchParams = new URLSearchParams(search);
        return parameterNames.reduce((accumulator, parameterName: ParamNames[number]) => {
            accumulator[ parameterName ] = searchParams.get(parameterName);
            return accumulator;
        }, {} as Record<ParamNames[number], string | null>);
    }, [ search, parameterNames.join(',') ]); // join for sake of reducing array of strings to simple, comparable string
}

然后你可以像这样在你的功能组件中使用它:

// current url: http://localhost:8000/#/signin?_k=v9ifuf&__firebase_request_key=blablabla
const { __firebase_request_key } = useSearchParams('__firebase_request_key');

// current url: http://localhost:3000/home?b=value
const searchParams = useSearchParameters('a', 'b'); // {a: null, b: 'value'}

从v4开始，React路由器不再直接在其location对象中提供查询参数。原因是

There are a number of popular packages that do query string parsing/stringifying slightly differently, and each of these differences might be the "correct" way for some users and "incorrect" for others. If React Router picked the "right" one, it would only be right for some people. Then, it would need to add a way for other users to substitute in their preferred query parsing package. There is no internal use of the search string by React Router that requires it to parse the key-value pairs, so it doesn't have a need to pick which one of these should be "right".

包含了这个之后，只解析location会更有意义。在需要查询对象的视图组件中搜索。

你可以通过覆盖react-router中的withRouter来实现这一点

customWithRouter.js

import { compose, withPropsOnChange } from 'recompose';
import { withRouter } from 'react-router';
import queryString from 'query-string';

const propsWithQuery = withPropsOnChange(
    ['location', 'match'],
    ({ location, match }) => {
        return {
            location: {
                ...location,
                query: queryString.parse(location.search)
            },
            match
        };
    }
);

export default compose(withRouter, propsWithQuery)

this.props.params。Your_param_name将工作。

这是从查询字符串中获取参数的方法。 请执行console.log(this.props);探索所有的可能性。

你可以使用下面的react钩子:

如果url改变，钩子状态会更新 SSR: typeof window === "undefined"，只是检查窗口导致错误(尝试一下) 代理对象隐藏实现，因此返回undefined而不是null

这是获取搜索参数为对象的函数:

const getSearchParams = <T extends object>(): Partial<T> => {
    // server side rendering
    if (typeof window === "undefined") {
        return {}
    }

    const params = new URLSearchParams(window.location.search) 

    return new Proxy(params, {
        get(target, prop, receiver) {
            return target.get(prop as string) || undefined
        },
    }) as T
}

然后像这样把它用作钩子:

const useSearchParams = <T extends object = any>(): Partial<T> => {
    const [searchParams, setSearchParams] = useState(getSearchParams())

    useEffect(() => {
        setSearchParams(getSearchParams())
    }, [typeof window === "undefined" ? "once" : window.location.search])

    return searchParams
}

如果你的url是这样的:

/app？page=2&count=10

你可以这样读:

const { page, count } = useQueryParams();

console.log(page, count)

我使用了一个名为query-string的外部包来解析url参数，如下所示。

import React, {Component} from 'react'
import { parse } from 'query-string';

resetPass() {
    const {password} = this.state;
    this.setState({fetching: true, error: undefined});
    const query = parse(location.search);
    return fetch(settings.urls.update_password, {
        method: 'POST',
        headers: {'Content-Type': 'application/json', 'Authorization': query.token},
        mode: 'cors',
        body: JSON.stringify({password})
    })
        .then(response=>response.json())
        .then(json=>{
            if (json.error)
                throw Error(json.error.message || 'Unknown fetch error');
            this.setState({fetching: false, error: undefined, changePassword: true});
        })
        .catch(error=>this.setState({fetching: false, error: error.message}));
}