为什么ES6 react类需要绑定

为什么ES6 react类需要绑定

你需要设置

this

的方法的情况下，例如，如果你需要传递函数引用到事件处理程序，但你并不需要一套

this

针对每一个方法，

class Counter extends React.Component {  constructor() {    super();    this.tick = this.tick.bind(this);  }  tick() {    // this refers to Counter  }  fn() {    // this refers to Counter  }  withoutBind() {    // this will be undefined or window it depends if you use "strict mode" or not  }  render() {    this.fn(); // this inside this method refers to Counter    // but if you will do like this    const fn = this.fn;    fn(); // this will refer to global scope    return <div>      <button onClick={this.tick}>1</button>      <button onClick={this.withoutBind}>2</button>    </div>;  }}

Example