React

by eugene chen

HTML

<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

li {
  margin: 8px 0;
}

h2 {
  font-weight: bold;
  margin-bottom: 15px;
}

.done {
  color: rgba(0, 0, 0, 0.3);
  text-decoration: line-through;
}

input {
  margin-right: 5px;
}

React

class LoginBox extends React.Component {
    render() {
        return (
            <div>
                <button onClick={this.props.onClickButton}>送出</button>
            </div>
        );
    }
}

class App extends React.Component {
  constructor(props) {
    super(props);
    this.handleClick = this.handleClick.bind(this); // 讓 handleClick() 裡的 this 是 App 自已
  }
  
  state = {
    message: '',
  }
  
  handleClick() {
    this.setState({
      message: 'hi',
    });
  }
  
  render() {
    return (
      <div>
        {this.state.message}
        <LoginBox onClickButton={this.handleClick} />
      </div>
    )
  }
}

ReactDOM.render(<App />, document.querySelector("#app"))