如何在组合框中获取当前选择的值(字符串)？

var selectBox = document.getElementById("selectBoxId");
var selectedValue = selectBox.options[selectBox.selectedIndex].value;

var selectedValue = $("#selectBoxId").val();

 <option v-for="option in options" v-bind:value="option.value">
    {{ option.text }}
  </option>
</select>

class SelectBox extends React.Component {
  constructor(props) {
    super(props);
    this.state = { selectedValue: '' };
  }

  handleChange = (event) => {
    this.setState({ selectedValue: event.target.value });
  }

  render() {
    return (
     <select value={this.state.selectedValue} onChange={this.handleChange}>
        {this.props.options.map((option) => (
         <option key={option.value} value={option.value}>
            {option.text}
          </option>
        ))}
      </select>
    );
  }
}