react

for循环

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

    // 这边绑定是必要的,这样 `this` 才能在回调函数中使用
    this.handleClick = this.handleClick.bind(this);
    
    const listItems = props.numbers.map((number) =>
    <li key={number.toString()} onClick={this.handleClick2.bind(this, number)}>
      {number} 点击
    </li>
    );
  
    this.state={listItems: listItems};
  
  }
  
  

  handleClick() {
    console.log(this);
    this.setState(prevState => ({
      isToggleOn: !prevState.isToggleOn
    }));
  }
  
  handleClick2(id,e) {
    alert(id);
    //console.log(this);
    
  }

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

const numbers = [1, 2, 3, 4, 5];

ReactDOM.render(
  <Toggle  numbers={numbers}/>,
  document.getElementById('example')
);

张泽
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