ReactJS，相同组件，从其他组件onClick切换类

Question

so I have a Main.jsx parent file, that takes two of the same component, but with different data attached to it. The Child component has a button with an onClick.

Main.jsx

    class Main extends React.Component {
    render() {
        return (
            <div className="row">
                    <Child
                        styleName="pane-1 text-center"
                        title="Title 1"
                        description="Some Text"
                    />
                    <Child
                        styleName="pane-2 text-center"
                        title="Title 2"
                        description="Some Text"
                    />
            </div>
        )
    }
}

export default Main

Child.jsx

class Child extends React.Component {

    render() {
        return (
            <div className={classnames('pane', this.props.colName)}>
                <div className={classnames(this.props.styleName)}>
                    <div className="col-sm-6 col-sm-offset-3">
                        <h2>{this.props.title}</h2>
                        <p>{this.props.description}</p>
                        <button onClick={this.togglePane} className="btn btn-primary-outline">Tell Me More</button>
                    </div>
                </div>
            </div>
        )
    }
}

export default Child

Now, in the above Child.jsx file the colName props is what needs to change, but only for the component that the user clicks the button on.

I tried the following in the Child.jsx file as well, but this does not seem to work, and from what I've read, its better to keep most components stateless as well:

constructor(props) {
        super(props);

        this.state = {
            colName: 'col-sm-6'
        };

        this.togglePane = this.togglePane.bind(this);
    }
    togglePane() {
       if (this.state.colName == 'col-sm-6'){
           this.setState({colName: 'col-sm-4'})
       } else {
           this.setState({colName: 'col-sm-6'})
       }
    }

Answer 1

This should be handled at the parent. Parent can make one be sm-8 and other be sm-4.

<button onClick={this.props.togglePane} />

In the parent, handle it

<Child
  styleName="pane-1 text-center"
  colName={this.state.firstCol}
  togglePane={this.togglePane}                     
/>
<Child
  styleName="pane-2 text-center"
  colName={this.state.secondCol}
  togglePane={this.togglePane}                     
/>

togglePane() {
  if(this.state.firstCol==='col-sm-6') {
    this.setState({ firstCol: 'col-sm-8', secondCol: 'col-sm-4' });
  } else {
    this.setState({ firstCol: 'col-sm-6', secondCol: 'col-sm-6' });
  }
}