我是第一次使用 React Context API。我有一个生成客户列表的表。最初,我将客户端存储在状态数组中,在同一页面中,我有一个根据点击对客户端进行排序的函数。
我已将客户端移至上下文中,而不是表格所在的实际页面的状态,但现在我的排序功能当然不再起作用。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
}
});
};
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;
未来编辑: 正如 @ziggy 在他们的评论中指出的那样,每当渲染此组件时,这都会导致所有使用者重新渲染,因为每次都会重新创建对象引用。尽管有一些保护措施,但考虑到 Context API 不是状态管理器,最好避免以这种方式使用它,而是探索其他解决方案。
也许是这样的?
<Context.Provider
value={{
state: this.state,
onSortClient: this.onSortClient,
}}
>
{this.props.children}
</Context.Provider>
所以,
value.state
将是你的状态,value.onSortClient
将是你的函数。