在学生(儿童)组件中
useEffect 挂钩将通过 handleStudentsChange(父组件提供的函数)更新父数组。在学生(家长)组件中
handleStudentsChange 函数使用 useCallback 挂钩定义。然而,它似乎不起作用。问题/疑问
handleStudentsChange 就会无限运行请参阅此处的代码: 我是 CodeSandBox 链接
Student.tsx(儿童)
import React, { useState, useEffect, useRef } from "react";
import TextField from "@mui/material/TextField";
interface student {
firstName: string;
lastName: string;
grade: number;
}
interface studentProps {
id: number;
firstName: string;
lastName: string;
grade: number;
handleStudentsChange: (index: number, student: student) => void;
}
function Student(props: studentProps) {
const [firstName, setFirstName] = useState(props.firstName);
const [lastName, setLastName] = useState(props.lastName);
const [grade, setGrade] = useState(props.grade);
useEffect(() => {
handleStudentsChange(id, {
firstName: firstName,
lastName: lastName,
grade: grade
});
}, [firstName, lastName, grade, props]);
return (
<>
setFirstName(event.target.value)}
value={firstName}
/>
setLastName(event.target.value)}
value={lastName}
/>
setGrade(+event.target.value)}
value={grade}
/>
>
);
Students.tsx(父级)
import React, { useState, useCallback } from "react";
import Student from "./Student";
interface student {
firstName: string;
lastName: string;
grade: number;
}
export default function Students() {
const [students, setStudents] = useState([
{ firstName: "Justin", lastName: "Bieber", grade: 100 },
{ firstName: "Robert", lastName: "Oppenhiemer", grade: 100 }
]);
const handleStudentsChange = useCallback(
(index: number, updatedStudent: student) => {
// console.log(index) //I only want this to rerender when the value change however it turn into an infinity loop
setStudents((prevStudents) => {
const updatedStudents = [...prevStudents];
updatedStudents[index] = updatedStudent;
return updatedStudents;
});
},
[]
);
return (
<>
{students.map((student, index) => {
return (
handleStudentsChange(index, newStudent)
}
/>
);
})}
>
);
}
如上面的代码所示,我尝试在学生(儿童)组件上使用 React.memo ,并在 handleStudentsChange 上使用 useCallback ,希望能够防止无限循环。然而,无限循环仍在继续。
Copyright 2014-2026 https://www.php.cn/ All Rights Reserved | php.cn | 湘ICP备2023035733号