退出react-Native中的摄影机视图

import React, { Component } from 'react';
import { View, Text, TouchableOpacity } from 'react-native';
import { RNCamera } from 'react-native-camera';

class CameraScreen extends Component {
  constructor(props) {
    super(props);
    this.state = {
      showCamera: true
    };
  }

  render() {
    if (this.state.showCamera) {
      return (
        <View style={{ flex: 1 }}>
          <RNCamera
            ref={ref => {
              this.camera = ref;
            }}
            style={{ flex: 1 }}
          />
          <TouchableOpacity
            onPress={() => this.setState({ showCamera: false })}
            style={{ position: 'absolute', bottom: 20, alignSelf: 'center' }}
          >
            <Text style={{ fontSize: 20, color: 'white' }}>退出摄像机视图</Text>
          </TouchableOpacity>
        </View>
      );
    } else {
      return (
        <View>
          <Text>已退出摄像机视图</Text>
        </View>
      );
    }
  }
}

class App extends Component {
  render() {
    return (
      <View style={{ flex: 1 }}>
        <CameraScreen />
      </View>
    );
  }
}