React总结3：ES6下React组件的写法示例代码

一：定义React组件

class Hello extends React.Component { render() {  return <h1>Hello, {this.props.value}</h1>; }}

二：声明prop类型与默认prop

class Hello extends React.Component { // ...}Hello.propTypes = { value: React.PropTypes.string};Hello.defaultProps = { value: 'world'};

三、设置初始state

class Hello extends React.Component { constructor(props) {  super(props);  this.state = {count: props.initialCount}; } // ...}

四、自动绑定

lass SayHello extends React.Component { constructor(props) {  super(props);  this.state = {message: 'Hello!'};  // 这行很重要  this.handleClick = this.handleClick.bind(this); } handleClick() {  alert(this.state.message); } render() {  // Because `this.handleClick` is bound, we can use it as an event handler.  return (   <button onClick={this.handleClick}>    Say hello   </button>  ); }}