将函数作为react中的属性传递，无法读取未定义的属性“”_handleEvent“”

// 父组件
import React from 'react';
import ChildComponent from './ChildComponent';

class ParentComponent extends React.Component {
  _handleEvent = () => {
    // 处理事件的逻辑
  }

  render() {
    return (
      <ChildComponent handleEvent={this._handleEvent} />
    );
  }
}

// 子组件
import React from 'react';

class ChildComponent extends React.Component {
  render() {
    const { handleEvent } = this.props;

    return (
      <div>
        {handleEvent && <button onClick={handleEvent}>触发事件</button>}
      </div>
    );
  }
}