React登录控制组件-优快云博客

本文链接：https://blog.youkuaiyun.com/u013761036/article/details/100907252

本文介绍了一个使用React实现的登录控制组件，该组件根据用户的登录状态显示不同的问候信息和按钮，包括登录和登出功能。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8" />
    <title>Learn React</title>
    <script src="https://cdn.staticfile.org/react/16.4.0/umd/react.development.js"></script>
    <script src="https://cdn.staticfile.org/react-dom/16.4.0/umd/react-dom.development.js"></script>
    <!-- 生产环境中不建议使用 -->
    <script src="https://cdn.staticfile.org/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/babel">

function UserGreeting(props){
    return <h1>Welcome back!</h1>;
}
function  GuestGreeting(props){
    return <h1>Please sign up.</h1>;
}
function Greeting(props){
    const isLoggedIn = props.isLoggedIn;
    if(isLoggedIn){
        return <UserGreeting/>;
    }else{
        return <GuestGreeting/>
    }
}

function LoginButton(props){
    return(
        <button onClick={props.onClick}>
            Login
        </button>
    );
}
function LogoutButton(props){
    return(
        <button onClick={props.onClick}>
            Logout
        </button>
    );
}

class LoginControl extends React.Component {
    constructor(props) {
        super(props);
        this.handleLoginClick = this.handleLoginClick.bind(this);
        this.handleLogoutClick = this.handleLogoutClick.bind(this);
        this.state = {isLoggedIn: false};
    }

    handleLoginClick() {
        this.setState({isLoggedIn: true});
    }

    handleLogoutClick() {
        this.setState({isLoggedIn: false});
    }

    render() {
        const isLoggedIn = this.state.isLoggedIn;
        let button;

        if (isLoggedIn) {
            button = <LogoutButton onClick={this.handleLogoutClick} />;
        } else {
            button = <LoginButton onClick={this.handleLoginClick} />;
        }

        return (
            <div>
            <Greeting isLoggedIn={isLoggedIn} />
            {button}
            </div>
    );
    }
}

ReactDOM.render(
<LoginControl />,
    document.getElementById('root')
);

</script>
</body>
</html>

React-条件渲染