javascript - 在 React 中移除事件监听器 (lodash.throttle)

Question

removeEventListener() 在我不使用 lodash 中的 throttle() 时有效。

   window.addEventListener('scroll', this.checkVisible, 1000, false);
     window.removeEventListener('scroll', this.checkVisible, 1000, false);

(我在构造函数中绑定(bind)了方法)

---

不幸的是，用 throttle(this.checkVisible) 函数环绕它 - 不起作用。我认为这是因为在尝试删除监听器时，throttle() 创建了新实例，也许我应该全局绑定(bind)它。怎么样(如果是这样的话)？

  import React from 'react';
    import throttle from 'lodash.throttle';
    
    class About extends React.Component {
      constructor(props) {
        super(props);
    
        this.checkVisible = this.checkVisible.bind(this);
      }
    
      componentDidMount() {
        window.addEventListener('scroll', throttle(this.checkVisible, 1000), false);
    
      }
    
      checkVisible() {
       if (window.scrollY > 450) {
        // do something
        window.removeEventListener('scroll', throttle(this.checkVisible, 1000),
        false);
        }
      }
    
      render() {
        return (
          <section id="about"> something
          </section>
        );
      }
    }
    
    export default About;

Answer 1

Lodash trottle 创建了一个节流函数，因此您需要存储对它的引用才能删除事件监听器。

import React from 'react';
import throttle from 'lodash.throttle';

class About extends React.Component {
  constructor(props) {
    super(props);

    this.checkVisible = this.checkVisible.bind(this);
    // Store a reference to the throttled function
    this.trottledFunction = throttle(this.checkVisible, 1000);
  }

  componentDidMount() {
    // Use reference to function created by lodash throttle
    window.addEventListener('scroll', this.trottledFunction, false);

  }

  checkVisible() {
   if (window.scrollY > 450) {
    // do something
    window.removeEventListener('scroll', this.trottledFunction, false);
    }
  }

  render() {
    return (
      <section id="about"> something
      </section>
    );
  }
}

export default About;