如何在render()中调用.selectedIndex？

import React, { Component } from 'react';

class MyComponent extends Component {
  constructor(props) {
    super(props);
    this.selectRef = React.createRef();
  }

  handleClick = () => {
    const selectedIndex = this.selectRef.current.selectedIndex;
    console.log('Selected index:', selectedIndex);
  }

  render() {
    return (
      <div>
        <select ref={this.selectRef}>
          <option value="option1">Option 1</option>
          <option value="option2">Option 2</option>
          <option value="option3">Option 3</option>
        </select>
        <button onClick={this.handleClick}>Get Selected Index</button>
      </div>
    );
  }
}

export default MyComponent;