reactjs - React의 setState는 선택적으로 상태를 업데이트합니다

문서별로 반응 네이티브 모달 날짜 시간 선택기를 사용하고 있습니다. 날짜 (handleStartDatePicked 함수 내의 콘솔 로그에 표시됨)를 this.state.startDateTime으로 저장하려고합니다. React의 setState를 사용 하여이 작업을 시도하고 있지만 작동하지 않습니다. 호기심으로 다른 속성 (아래 예제 'startDateTimeNew'에서)을 변경하려고 시도했으며 이것이 올바르게 업데이트되고 있습니다. 의도 한 변수 'startDateTime'이 업데이트되지 않는 이유에 대해 잘 모르겠습니다.

import React, { Component } from 'react';
import { connect } from 'react-redux';
import {
  Text,
  View,
  StyleSheet,
  TextInput,
  TouchableOpacity,
} from 'react-native';
import DateTimePicker from 'react-native-modal-datetime-picker';
import moment from 'moment';
class SessionScreen extends Component {
  static navigationOptions = {
    title: 'View Session',
  };
  state = {
    details: '',
    endDateTime: '',
    endDateTimePickerVisible: false,
    startDateTime: '',
    startDateTimePickerVisible: false,
  };
  handleEndDatePicked = (date) => {
    console.log('A date has been picked: ', date);
    this.hideEndDateTimePicker();
  };
  handleInputChangeFor = (propertyName,text) => {
    this.setState({
        ...this.state,
        [propertyName]: text,
    });
    console.log('this.state:',this.state);
  }
  handleStartDatePicked = (date) => {
    console.log('A date has been picked: ', date, 'formatted:', moment(date).format('dddd[,] MMM Do h:mm A'));
    this.setState({
        ...this.state,
        startDateTimeNew: date.toString(),
        startDateTime: date.toString(),
    }, function() {
        console.log('new state',this.state);
    });
    console.log('this.state:', this.state);
    this.hideStartDateTimePicker();
  };
  hideEndDateTimePicker = () => this.setState({ ...this.state, endDateTimePickerVisible: false });
  hideStartDateTimePicker = () => this.setState({ ...this.state, startDateTimePickerVisible: false });
  showEndDateTimePicker = () => this.setState({ ...this.state, endDateTimePickerVisible: true });
  showStartDateTimePicker = () => this.setState({ ...this.state, startDateTimePickerVisible: true });
  render() {
    const {navigate} = this.props.navigation;
    return (
      <View style={styles.container}>
        <Text style={styles.header}>START TIME</Text>
        <TouchableOpacity onPress={this.showStartDateTimePicker} style={styles.touchableOpacity}>
          {/* <Text style={styles.touchableOpacityText}><this.dateTimeStart /></Text> */}
          <Text style={styles.touchableOpacityText}>Click to set start day and time</Text>
        </TouchableOpacity>
        <Text style={styles.header}>END TIME</Text>
        <TextInput 
            style={styles.input}
            placeholder="Click to add end day and time..."
            returnKeyType="go"
            autoCapitalize="none"
            autoCorrect={false}
            onChangeText={(input) => this.handleInputChangeFor('end',input)}
        />
        <Text style={styles.header}>DETAILS</Text>
        <TextInput 
            style={styles.input}
            placeholder="Enter details about this chill..."
            returnKeyType="go"
            autoCapitalize="none"
            autoCorrect={false}
            onChangeText={(input) => this.handleInputChangeFor('details',input)}
        />
        <DateTimePicker
          isVisible={this.state.startDateTimePickerVisible}
          onConfirm={this.handleStartDatePicked}
          onCancel={this.hideStartDateTimePicker}
          mode={'datetime'}
        />
      </View>
    );
  }
}
const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: '#b2f6ff',
    padding: 10
  },
  header: {
    fontSize: 14,
    marginBottom: 8,
    color: 'black',
    opacity: 0.8,
  },
  input: {
    height: 40,
    backgroundColor: 'white',
    marginBottom: 10,
    paddingHorizontal: 10,
    width: 'auto'
  },
  touchableOpacity: {
    height: 40,
    backgroundColor: 'white',
    marginBottom: 10,
    paddingHorizontal: 10,
    width: 'auto',
    justifyContent: 'center',
  },
  touchableOpacityText: {
    opacity: 0.5
  }
})
const mapReduxStateToProps = reduxState => (
  {reduxState}
);
export default connect(mapReduxStateToProps)(SessionScreen);

date.toString ()과 moment (date) .format ( 'dddd [,] MMM Do h : mm A'를 사용하여 startDateTime 설정을 시도했습니다. 함수에 입력 한 날짜는 객체이지만 성공적으로 올바른 데이터가 포함 된 문자열로 바뀝니다.