在 React 中切换类 [英] Toggle Class in React

问题描述

我正在为一个有菜单按钮的项目使用 React.

<a ref="btn" href="#" className="btn-menu show-on-small"><i></i></a>

还有一个 Sidenav 组件，例如:

我编写了以下代码来切换菜单:

class Header extends React.Component {构造函数(道具){超级(道具)；this.toggleSidenav = this.toggleSidenav.bind(this);}使成为() {返回 (<div className="header"><i className="border hide-on-small-and-down"></i><div className="容器"><a ref="btn" href="#" className="btn-menu show-on-small"><i></i></a><Menu className="menu hide-on-small-and-down"/><Sidenav/>

)}切换Sidenav() {this.refs.btn.classList.toggle('btn-menu-open');}componentDidMount() {this.refs.btn.addEventListener('click', this.toggleSidenav);}componentWillUnmount() {this.refs.btn.removeEventListener('click', this.toggleSidenav);}}

问题是 this.refs.sidenav 不是 DOM 元素，我无法在他身上添加类.

有人可以解释我如何像在按钮上那样在 Sidenav 组件上切换类吗?

解决方案

如果你想让 React 正确高效地渲染你的 DOM，你必须使用组件的 State 来更新组件参数，比如 Class Name.

更新:我更新了示例以在单击按钮时切换侧边菜单.这不是必需的，但您可以看到它是如何工作的.正如我所展示的，您可能需要使用this.state"与this.props".我习惯于使用 Redux 组件.

构造函数(道具){超级(道具)；}getInitialState(){返回{showHideSidenav":隐藏"}；}使成为() {返回 (<div className="header"><i className="border hide-on-small-and-down"></i><div className="容器"><a ref="btn" onClick={this.toggleSidenav.bind(this)} href="#" className="btn-menu show-on-small"><i></i></a＞<Menu className="menu hide-on-small-and-down"/><Sidenav className={this.props.showHideSidenav}/>

)}切换Sidenav() {var css = (this.props.showHideSidenav === "隐藏") ?显示":隐藏"；this.setState({"showHideSidenav":css});}

现在，当您切换状态时，组件将更新并更改 sidenav 组件的类名.您可以使用 CSS 来显示/隐藏使用类名称的 sidenav.

.hidden {显示:无；}.表演{显示:块；}

I'm using react for a project where I have a menu button.

<a ref="btn" href="#" className="btn-menu show-on-small"><i></i></a>

And a Sidenav component like:

<Sidenav ref="menu" />

And I wrote the following code to toggle the menu:

class Header extends React.Component {

    constructor(props){
        super(props);
        this.toggleSidenav = this.toggleSidenav.bind(this);
    }

    render() {
        return (
          <div className="header">
            <i className="border hide-on-small-and-down"></i>
            <div className="container">
          <a ref="btn" href="#" className="btn-menu show-on-small"><i></i></a>
          <Menu className="menu hide-on-small-and-down"/>
          <Sidenav />
        </div>
          </div>
        )
    }

    toggleSidenav() {
        this.refs.btn.classList.toggle('btn-menu-open');
    }

    componentDidMount() {
        this.refs.btn.addEventListener('click', this.toggleSidenav);
    }

    componentWillUnmount() {
        this.refs.btn.removeEventListener('click', this.toggleSidenav);
    }
}

The thing is that this.refs.sidenav is not a DOM element and I cant add a class on him.

Can someone explain me how to toggle class on the Sidenav component like I do on my button?

解决方案

You have to use the component's State to update component parameters such as Class Name if you want React to render your DOM correctly and efficiently.

UPDATE: I updated the example to toggle the Sidemenu on a button click. This is not necessary, but you can see how it would work. You might need to use "this.state" vs. "this.props" as I have shown. I'm used to working with Redux components.

constructor(props){
    super(props);
}

getInitialState(){
  return {"showHideSidenav":"hidden"};
}

render() {
    return (
        <div className="header">
            <i className="border hide-on-small-and-down"></i>
            <div className="container">
                <a ref="btn" onClick={this.toggleSidenav.bind(this)} href="#" className="btn-menu show-on-small"><i></i></a>
                <Menu className="menu hide-on-small-and-down"/>
                <Sidenav className={this.props.showHideSidenav}/>
            </div>
        </div>
    )
}

toggleSidenav() {
    var css = (this.props.showHideSidenav === "hidden") ? "show" : "hidden";
    this.setState({"showHideSidenav":css});
}

Now, when you toggle the state, the component will update and change the class name of the sidenav component. You can use CSS to show/hide the sidenav using the class names.

.hidden {
   display:none;
}
.show{
   display:block;
}

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