反应选择“无法读取未定义的属性‘值’”

如何解决反应选择“无法读取未定义的属性‘值’”

我正在尝试实现“react-select”，但我收到“TypeError：无法读取未定义的属性“值””。从选择框中选择值时，将调用 handleSelectInput 事件，但不会将 selectedType 状态变量设置为所选值。 代码有什么问题？

import React,{ Component } from 'react';
import Select from 'react-select';

const options = [
  {value:'sqFeet',label:'Square Feet'},{value:'acre',label:'Acre'},{value:'cent',label:'Cent'}
]
class RegisterProperty extends Component {
    constructor(props) {
        super(props)
        this.state = {
            selectedType:''
        }
        this.handleSelectChange = this.handleSelectChange.bind(this)
    }
    handleSelectChange(event) {   
        console.log(event) //prints the selected option     
        this.setState({
            selectedType:event.target // selectedType is undefined
        })      
    }
    render() {
        return(
          <div id="content">
            <form onSubmit={(event) => {
               event.preventDefault()
               const propertyType = this.state.selectedType
               console.log(propertyType) // prints undefined
            <div className="col-sm-3"><Select options={options} onChange={this.handleSelectChange} />
            <button type="submit" className="btn btn-dark" onClick={this.handleSubmit}>Register Property</button>
          </div>
        )
    }
}