componentDidUpdate - 错误：超出最大更新深度

Question

class Suggestions extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            visible: false
        }

        this.handleClick = this.handleClick.bind(this);
    }

    handleClick(event) {
        console.log(event.target.value)
    }

    componentDidUpdate(props, state) {
        if(props.dataSearchBox) {
            this.setState({visible: true})

        } else {
            this.setState({visible: false})
        }
    }

    render() {
        return (
            <div className={`g${this.state.visible === true ? '': ' h'}`}>
                <ul>
                </ul>
            </div>
        );
    }
}
export default Suggestions;

I am trying to set the state based on the props change, however I get the following error inside componentDidUpdate :

There was an error! Error: Maximum update depth exceeded. This can happen when a component repeatedly calls setState inside componentWillUpdate or componentDidUpdate. React limits the number of nested updates to prevent infinite loops.

What am I doing wring here?

Answer 1

Your problem is here:

componentDidUpdate(props, state) {
    if(props.dataSearchBox) {
        this.setState({visible: true})

    } else {
        this.setState({visible: false})
    }
}

componentDidUpdate gets called, it sets the state, which triggers componentDidUpdate ... round and round.

Do you need a separate state property to handle this? That's a bit of an anti-pattern - you have what you need already as a prop, just use its value to control the visibility directly:

render() {
    return (
        <div className={`g${this.props.dataSearchBox ? '': ' h'}`}>
            <ul>
            </ul>
        </div>
    );
}