将具有React Context API的函数传递给嵌套在树中深处的子组件

acd*_*d37 7 javascript reactjs react-props

我第一次使用React Context API.我有一个表生成客户列表.最初,我将客户端存储在一个状态的数组中,并且在同一页面中,我有一个根据点击对客户端进行排序的功能.

我已经将客户端移动到上下文而不是表格的实际页面的状态,但现在我的排序函数当然不再有效.我需要做的是使用相同的函数,但组织处于上下文状态的数组.

原功能:

onSortClient = column => e => {
        const direction = this.state.sort.column
            ? this.state.sort.direction === "asc"
                ? "desc"
                : "asc"
            : "desc";
        const sortedData = this.state.clients.sort((a, b) => {
            if (column === "client_name") {
                const nameA = a.client_name.toUpperCase();
                const nameB = b.client_name.toUpperCase();
                if (nameA < nameB) {
                    return -1;
                }
                if (nameA > nameB) {
                    return 1;
                }

                return 0;
            }
            return 0;
        });

        if (direction === "desc") {
            sortedData.reverse();
        }

        this.setState({
            clients: sortedData,
            sort: {
                column,
                direction
            }
        });
    };
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我的上下文文件:

import React, { Component } from "react";
import axios from "axios";

const Context = React.createContext();

const Reducer = (state, action) => {
    switch (action.type) {
        case "DELETE_CLIENT":
            console.log(action.payload);
            return {
                ...state,
                clients: state.clients.filter(client => client.id !== action.payload)
            };
        case "ADD_CLIENT":
            return {
                ...state,
                clients: [action.payload, ...state.clients]
            };
        case "UPDATE_CLIENT":
            console.log(action.payload);
            return {
                ...state,
                clients: state.clients.map(
                    client =>
                        client.id === action.payload.id ? (client = action.payload) : client
                )
            };

        default:
            return state;
    }
};

export class Provider extends Component {
    state = {
        clients: [],
        loaded: false,
        dispatch: action => {
            this.setState(state => Reducer(state, action));
        }
    };

    async componentDidMount() {
        let localToken = localStorage.getItem("iod_tkn");

        const res = await axios({
            url: "/users/get_clients",
            method: "get",
            headers: {
                Authorization: localToken
            }
        });

        this.setState({
            clients: res.data,
            loaded: true
        });
    }


    render() {
        return (
            <Context.Provider onSortClient={this.onSortClient} value={this.state}>
                {this.props.children}
            </Context.Provider>
        );
    }
}

export const Consumer = Context.Consumer;
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dev*_*kan 13

也许是这样的?

<Context.Provider
    value={{
        state: this.state,
        onSortClient: this.onSortClient,
    }}
>
    {this.props.children}
</Context.Provider>
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那么,value.state将是你的状态,value.onSortClient将是你的功能.

  • 我觉得有必要指出,如果您按原样使用此代码,则每次该组件重新渲染时,消耗此状态的每个组件都会重新渲染。这是因为您正在创建一个新对象,以便在每次渲染时传递给“value”。请参阅:https://reactjs.org/docs/context.html#caveats (9认同)