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@koistya
Last active June 8, 2022 09:55
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How to add `onscroll` event in ReactJS component
import React from 'react';
let lastScrollY = 0;
let ticking = false;
class App extends React.Component {
componentDidMount() {
window.addEventListener('scroll', this.handleScroll, true);
}
componentWillUnmount() {
window.removeEventListener('scroll', this.handleScroll);
}
nav = React.createRef();
handleScroll = () => {
lastScrollY = window.scrollY;
if (!ticking) {
window.requestAnimationFrame(() => {
this.nav.current.style.top = `${lastScrollY}px`;
ticking = false;
});
ticking = true;
}
};
render() {
return (
<div>
<nav ref={this.nav}>
</nav>
<div>
);
}
}
export default App;
@raheemazeezabiodun
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This worked for me:

constructor(props) {
  super(props);
  this.handleScroll = this.handleScroll.bind(this);
}

componentDidMount() {
  window.addEventListener('scroll', this.handleScroll);
};

componentWillUnmount() {
  window.removeEventListener('scroll', this.handleScroll);
};

handleScroll(event) {
  console.log('the scroll things', event)
};

your solution worked for me. Thank you for this

@koistya
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Author

koistya commented Aug 4, 2020

@raheemazeezabiodun Note, that if you use an arrow function syntax for declaring custom handlers, you won't need to bind them to this inside of a constructor function:

constructor(props) {
  supert(props);
  this.handleScroll = this.handleScroll.bind(this);
}

handleScroll(event) { ... };

vs

handleScroll = (event) => { ... };

@Random-Black-Coder
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Is anyone having issues with the event returning as undefined?

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