当用户登录时,我想显示一个按钮。如果用户未登录,则不会显示按钮。当用户登录时,我将设置本地存储值。当我在登录组件中设置本地存储时,头部组件必须监听该事件并显示按钮。我使用addEventListener来进行监听。但它不起作用。
我不知道在头部组件中应该监听哪个事件。
// HeaderComponent(header.js):
我不知道在头部组件中应该监听哪个事件。
// HeaderComponent(header.js):
class HeaderComponent extends Component {
componentDidMount(){
if(typeof window!='undefined'){
console.log(localStorage.getItem("token"));
window.addEventListener("storage",function(e){
this.setState({ auth: true});
})
}
}
render() {
return (
<div className="header">
<div className="container">
<div className="header-content">
<img src={logo} alt="logo"></img>
<div className="nav-links" >
<ul >
<li>Home</li>
<li>About</li>
<li>Services</li>
<li><NavLink activeClassName="active" to="/upload" >Upload</NavLink></li>
<li><NavLink activeClassName="active" to="/signup"> Sign Up</NavLink></li>
{ this.state.auth? <li onClick={this.onLogout}>Logout</li> :null}
</ul>
</div>
</div>
</div>
</div>
);
}
}
//登录组件(login.js)
class LoginComponent extends Component {
constructor(props) {
super(props);
this.onSubmit = this.onSubmit.bind(this);
}
onSubmit(event) {
const data = {
username: document.getElementById('name').value,
password: document.getElementById('password').value
}
axios.post(`http://localhost:4000/user/login`, data).then(res => {
this.props.history.push("/");
localStorage.setItem("token",res.data.token);
localStorage.setItem("auth",true);
}).catch(err => console.log(err));
}
render() {
return (
<section class="log-in">
<div class="card-col">
<form>
<h3>LOG IN</h3>
<div class="form-controls">
<input id="name" type="text" placeholder="username" class="input"></input>
</div>
<div class="form-controls">
<input id="password" type="password" placeholder="password" class="input"></input>
</div>
<button type="submit" onClick={this.onSubmit} class="button" >Log in</button>
</form>
</div>
</section>
)
}
}
LoginComponent
在该父级中设置auth
状态,然后将其作为prop
传递给HeaderComponent
。 - sallf