SOURCE

class Test extends React.Component {
  render() {
    return (
      console.log(this),
      <h1>提交</h1>
    )
  }
}

ReactDOM.render(<Test />, document.getElementById("root"));

class ActionLink extends React.Component {
  handleClick( e ) {
    e.preventDefault();
    console.log('The link was clicked.');
  }
  mouseOver(x) {
    console.log(x.target);
   
    
  }
  
  render() {
    return (
      <div>
        <a href="http://baidu.com.cn" onClick={this.handleClick}>
           Click me
        </a>
      <h1 onMouseOver = {this.mouseOver}>onmhouseover效果</h1>
      </div>
  );
  }
}
ReactDOM.render(<ActionLink />, document.getElementById("example"));

<script src='https://unpkg.com/react/umd/react.production.min.js'>
</script>
<script src='https://unpkg.com/react-dom/umd/react-dom.production.min.js'>
</script>

<div id="root"></div>
<div id="example"></div>