我第一次摆弄React.js,找不到一种方法通过单击事件在页面上显示或隐藏一些东西。我没有加载任何其他库到页面,所以我正在寻找一些使用React库的本地方式。这是我目前得到的。我想在点击事件触发时显示结果div。

var Search= React.createClass({
    handleClick: function (event) {
        console.log(this.prop);
    },
    render: function () {
        return (
            <div className="date-range">
                <input type="submit" value="Search" onClick={this.handleClick} />
            </div>
        );
    }
});

var Results = React.createClass({
    render: function () {
        return (
            <div id="results" className="search-results">
                Some Results
            </div>
        );
    }
});

React.renderComponent(<Search /> , document.body);

当前回答

2020年左右的反应

在onClick回调中,调用状态钩子的setter函数来更新状态并重新呈现:

const Search = () => { const [showResults, setShowResults] = React.useState(false) const onClick = () => setShowResults(true) return ( <div> <input type="submit" value="Search" onClick={onClick} /> { showResults ? <Results /> : null } </div> ) } const Results = () => ( <div id="results" className="search-results"> Some Results </div> ) ReactDOM.render(<Search />, document.querySelector("#container")) <script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.1/umd/react.production.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.1/umd/react-dom.production.min.js"></script> <div id="container"> <!-- This element's contents will be replaced with your component. --> </div>

JSFiddle

大约2014年

关键是使用setState更新单击处理程序中组件的状态。当状态改变被应用时,渲染方法会再次被调用,并使用新的状态:

var Search = React.createClass({ getInitialState: function() { return { showResults: false }; }, onClick: function() { this.setState({ showResults: true }); }, render: function() { return ( <div> <input type="submit" value="Search" onClick={this.onClick} /> { this.state.showResults ? <Results /> : null } </div> ); } }); var Results = React.createClass({ render: function() { return ( <div id="results" className="search-results"> Some Results </div> ); } }); ReactDOM.render( <Search /> , document.getElementById('container')); <script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.2/react.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/15.6.2/react-dom.min.js"></script> <div id="container"> <!-- This element's contents will be replaced with your component. --> </div>

JSFiddle

其他回答

下面是三元操作符的另一种语法:

{ this.state.showMyComponent ? <MyComponent /> : null }

等价于:

{ this.state.showMyComponent && <MyComponent /> }

学习的原因


还有显示的替代语法:'none';

<MyComponent style={this.state.showMyComponent ? {} : { display: 'none' }} />

然而,如果你过度使用display: 'none',这将导致DOM污染,并最终降低应用程序的速度。

你必须在代码中做一些小的改变来持续隐藏和显示

const onClick = () => {setShowResults(!showResults}

问题会得到解决

const Search = () => {
  const [showResults, setShowResults] = React.useState(false)
  const onClick = () => setShowResults(true)
  const onClick = () => {setShowResults(!showResults}
  return (
    <div>
      <input type="submit" value="Search" onClick={onClick} />
      { showResults ? <Results /> : null }
    </div>
  )
}
const Results = () => (
  <div id="results" className="search-results">
    Some Results
  </div>
)
ReactDOM.render(<Search />, document.querySelector("#container"))
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.1/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.1/umd/react-dom.production.min.js"></script>
<div id="container">
  <!-- This element's contents will be replaced with your component. -->
</div>
```

2020年左右的反应

在onClick回调中,调用状态钩子的setter函数来更新状态并重新呈现:

const Search = () => { const [showResults, setShowResults] = React.useState(false) const onClick = () => setShowResults(true) return ( <div> <input type="submit" value="Search" onClick={onClick} /> { showResults ? <Results /> : null } </div> ) } const Results = () => ( <div id="results" className="search-results"> Some Results </div> ) ReactDOM.render(<Search />, document.querySelector("#container")) <script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.1/umd/react.production.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.1/umd/react-dom.production.min.js"></script> <div id="container"> <!-- This element's contents will be replaced with your component. --> </div>

JSFiddle

大约2014年

关键是使用setState更新单击处理程序中组件的状态。当状态改变被应用时,渲染方法会再次被调用,并使用新的状态:

var Search = React.createClass({ getInitialState: function() { return { showResults: false }; }, onClick: function() { this.setState({ showResults: true }); }, render: function() { return ( <div> <input type="submit" value="Search" onClick={this.onClick} /> { this.state.showResults ? <Results /> : null } </div> ); } }); var Results = React.createClass({ render: function() { return ( <div id="results" className="search-results"> Some Results </div> ); } }); ReactDOM.render( <Search /> , document.getElementById('container')); <script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.6.2/react.min.js"></script> <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/15.6.2/react-dom.min.js"></script> <div id="container"> <!-- This element's contents will be replaced with your component. --> </div>

JSFiddle

只要找到一种新的、神奇的方法来使用(useReducer)功能组件

const [state, handleChangeState] = useReducer((state) => !state, false); 改变状态

<style type="text/css">
    .hidden { display:none; }
</style>
const Example = props => 
  <div className={props.shouldHide? 'hidden' : undefined}>Hello</div>