效果图，因为我用的是模拟器，所以拍照功能没有效果，不过可从相册选择，下面是具体的效果图
把react-native-image-picker添加到项目
yarn add react-native-image-picker
plist文件设置
<key>NSPhotoLibraryUsageDescription</key><string>$(PRODUCT_NAME) would like access to your photo gallery</string><key>NSCameraUsageDescription</key><string>$(PRODUCT_NAME) would like to use your camera</string><key>NSPhotoLibraryAddUsageDescription</key><string>$(PRODUCT_NAME) would like to save photos to your photo gallery</string><key>NSMicrophoneUsageDescription</key><string>$(PRODUCT_NAME) would like to your microphone (for videos)</string>
xcode设置：
1.In the XCode's "Project navigator", right click on your project's Libraries folder ➜ Add Files to <...>.
2.Go to node_modules ➜ react-native-image-picker ➜ ios ➜ select RNImagePicker.xcodeproj.
Add RNImagePicker.a to Build Phases -> Link Binary With Libraries.
代码集成步骤：
/*** Sample React Native App* https://github.com/facebook/react-native* @flow*/import React, {Component} from 'react';
import {AppRegistry,StyleSheet,Text,View, TouchableOpacity,Image
} from 'react-native';
import ImagePicker from 'react-native-image-picker';
export default class MyApp extends Component {constructor(props){super(props)this.state={avatarSource:null}}render() {const photoOptions = {title: '请选择',quality: 0.8,cancelButtonTitle: '取消',takePhotoButtonTitle: '拍照',chooseFromLibraryButtonTitle: '选择相册',allowsEditing: true,noData: false,storageOptions: {skipBackup: true,path: 'images'}};return (<View style={styles.container}><TouchableOpacity onPress = {()=>{ImagePicker.showImagePicker(photoOptions, (response) => {console.log('Response = ', response);if (response.didCancel) {console.log('User cancelled image picker');}else if (response.error) {console.log('ImagePicker Error: ', response.error);}else if (response.customButton) {console.log('User tapped custom button: ', response.customButton);}else {let source = { uri: response.uri };// You can also display the image using data:// let source = { uri: 'data:image/jpeg;base64,' + response.data };this.setState({avatarSource: source});}});}}><Text style={styles.welcome}>Welcome to React Native!</Text></TouchableOpacity><Image source={this.state.avatarSource} style={{width:100,height:100}}/></View>);}
}const styles = StyleSheet.create({container: {flex: 1,justifyContent: 'center',alignItems: 'center',backgroundColor: '#F5FCFF',},welcome: {fontSize: 20,textAlign: 'center',margin: 10,},instructions: {textAlign: 'center',color: '#333333',marginBottom: 5,},
});AppRegistry.registerComponent('MyApp', () => MyApp);