我刚接触React,尝试设置一个Bootstrap模态框来显示警告信息。
在我的父组件App.js文件中,我有一个错误处理程序,它会向Modal.js组件发送一个属性,以触发模态框的显示,例如:
在App.js中:
function App() {
const [modalShow, setModalShow] = useState(false);
// Some other handlers
const alertModalHandler = (modalMessage) => {
console.log(modalMessage);
setModalShow(true);
}
return (
// Other components.
<AlertModal modalOpen={modalShow}/>
)
}
关于 Modal.js:
import React, { useState } from "react";
import Modal from "react-bootstrap/Modal";
import "bootstrap/dist/css/bootstrap.min.css";
const AlertModal = (props) => {
const [isOpen, setIsOpen] = useState(false);
if (props.modalOpen) {
setIsOpen(true);
}
return (
<Modal show={isOpen}>
<Modal.Header closeButton>Hi</Modal.Header>
<Modal.Body>asdfasdf</Modal.Body>
</Modal>
);
};
export default AlertModal;
然而,这并不起作用。我收到了以下错误:
Uncaught Error: Too many re-renders. React limits the number of renders to prevent an infinite loop.
如果我将Modal组件更改为“哑”组件并直接使用prop,例如:
const AlertModal = (props) => {
return (
<Modal show={props.modalOpen}>
<Modal.Header closeButton>Hi</Modal.Header>
<Modal.Body>asdfasdf</Modal.Body>
</Modal>
);
};
它确实可以工作,但我想在Modal.js组件层面上改变显示/隐藏状态,例如有些东西在那里处理模态框关闭按钮。
我不明白为什么会出现问题?
这是否意味着我必须在父级App.js层面上处理模态框关闭函数?
编辑 - 完整的app.js内容
import React, { useState } from 'react';
import './App.css';
import 'bootstrap/dist/css/bootstrap.css';
import AddUserForm from './components/addUserForm';
import UserList from './components/userList';
import AlertModal from './components/modal';
function App() {
const [users, setUsers] = useState([]);
const [modalShow, setModalShow] = useState(false);
const addPersonHandler = (nameValue, ageValue) => {
console.log(nameValue, ageValue);
setUsers(prevUsers => {
const updatedUsers = [...prevUsers];
updatedUsers.unshift({ name: nameValue, age: ageValue });
return updatedUsers;
});
};
const alertModalHandler = (modalMessage) => {
console.log(modalMessage);
setModalShow(true);
}
let content = (
<p style={{ textAlign: 'center' }}>No users found. Maybe add one?</p>
);
if (users.length > 0) {
content = (
<UserList items={users} />
);
}
return (
<>
<div className="container">
<div className="row">
<div className="col-md-6 offset-md-3">
<AddUserForm onAddPerson={addPersonHandler} fireAlertModal={alertModalHandler}/>
</div>
</div>
<div className="row">
<div className="col-md-6 offset-md-3">
{content}
</div>
</div>
</div>
<AlertModal modalOpen={modalShow}/>
</>
);
}
export default App;