React事件处理程序

function ActionLink() {
function handleClick(e) {
    e.preventDefault();
    console.log('The link was clicked.');
  }

return (
<a href="#" onClick={handleClick}>
      Click me
</a>
  );
}

When using React you should generally not need to call addEventListener to add listeners to a DOM element after it is created. Instead, just provide a listener when the element is initially rendered.

Becareful about 'this':

class Toggle extends React.Component {
  constructor(props) {
    super(props);
this.state = {isToggleOn: true};

// This binding is necessary to make `this` work in the callback
this.handleClick = this.handleClick.bind(this);
  }

  handleClick() {
this.setState(prevState => ({
      isToggleOn: !prevState.isToggleOn
    }));
  }

  render() {
return (
<button onClick={this.handleClick}>
        {this.state.isToggleOn ? 'ON' : 'OFF'}
</button>
    );
  }
}

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

或者可以用下面的方法解决： （利用ES6箭头函数）

class LoggingButton extends React.Component {
// This syntax ensures `this` is bound within handleClick.
// Warning: this is *experimental* syntax.
  handleClick = () => {
    console.log('this is:', this);
  }

  render() {
return (
<button onClick={this.handleClick}>
        Click me
</button>
    );
  }
}

或者

class LoggingButton extends React.Component {
  handleClick() {
    console.log('this is:', this);
  }

  render() {
// This syntax ensures `this` is bound within handleClick
return (
<button onClick={(e) => this.handleClick(e)}>
        Click me
</button>
    );
  }
}

 

 以上均来自于react官网docs。

 

可以在js 中用debugger来断点调试