TextInputとイベント 【これからはじめるReact Native】

import React, { Component } from 'react';
import { Text, View, StyleSheet, TextInput } from 'react-native';
import { Constants } from 'expo';

// You can import from local files
import AssetExample from './components/AssetExample';

// or any pure javascript modules available in npm
import { Card } from 'react-native-elements'; // 0.18.5

export default class App extends Component {
  state = {
    inputValue: "You can change me!"
  };

  _handleTextChange = inputValue => {
    this.setState({ inputValue });
  };

  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.paragraph}>
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        </Text>

        <TextInput
          value={this.state.inputValue}
          onChangeText={this._handleTextChange}
          style={{ width: 200, height: 44, padding: 8 }}
        />

      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    alignItems: 'center',
    justifyContent: 'center',
    paddingTop: Constants.statusBarHeight,
    backgroundColor: '#ecf0f1',
  },
  paragraph: {
    margin: 24,
    fontSize: 18,
    fontWeight: 'bold',
    textAlign: 'center',
    color: '#34495e',
  },
});

<TextInput
  value={this.state.inputValue}
  onChangeText={this._handleTextChange}
  style={{ width: 200, height: 44, padding: 8 }}
/>

  state = {
    inputValue: "You can change me!"
  };

  _handleTextChange = inputValue => {
    this.setState({ inputValue });
  };

  constructor(props) {
    super(props);
    this.state = { inputValue: 'You can change me!' };
  }

  _handleTextChange = inputValue => {
    this.setState({ inputValue });
  };

_handleTextChange = function(inputValue) { 
  return this.setState(inputValue)
 }.bind(this)

        <Text style={styles.paragraph}>
          {this.state.inputValue}
        </Text>