react-native-image-picker作为一个集成相机和相册的功能的第三方库，因为其使用相对简单受到前端开发人员的喜爱。

react-native-image-picker使用

1， 首先,安装下该插件。

npm install react-native-image-picker@latest --save

2， 针对Android和iOS平台分别进行配置

## android 平台配置

1，在android/settings.gradle文件中添加如下代码：

include ':react-native-image-picker'
project(':react-native-image-picker').projectDir = new File(settingsDir, '../node_modules/react-native-image-picker/android')

2，在android/app/build.gradle文件的dependencies中添加如下代码：

compile project(':react-native-image-picker')

3，在AndroidManifest.xml文件中添加权限：

<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

4，最后在MainApplication.Java文件中添加如下代码：

import com.imagepicker.ImagePickerPackage;
 new ImagePickerPackage()

这样Android环境就配置好了。

iOS平台配置

1，打开Xcode打开项目,点击根目录,右键选择　Add Files to ‘XXX’,选中项目中的该路径下的文件即可:node_modules -> react-native-image-picker -> ios -> select RNImagePicker.xcodeproj

2，添加成功后使用link命令：react-native link react-native-image-picker 。
3，打开项目依次使用Build Phases -> Link Binary With Libraries将RNImagePicker.a添加到项目依赖。

4，对于iOS 10+设备，需要在info.plist中配置NSPhotoLibraryUsageDescription和NSCameraUsageDescription。

react-native-image-picker示例

为了项目使用的方便，我们将其封装为一个组件CameraButton.js。代码如下：

import React from 'react'
import {
    TouchableOpacity,
    StyleSheet,
    Platform,
    ActivityIndicator,
    View,
    Text,
    ToastAndroid
} from 'react-native'

var ImagePicker = require('react-native-image-picker');
import Icon from 'react-native-vector-icons/Ionicons';

const options = {
    title: '选择图片', 
    cancelButtonTitle: '取消',
    takePhotoButtonTitle: '拍照', 
    chooseFromLibraryButtonTitle: '图片库', 
    cameraType: 'back',
    mediaType: 'photo',
    videoQuality: 'high', 
    durationLimit: 10,
    maxWidth: 600,
    maxHeight: 600,
    aspectX: 2, 
    aspectY: 1,
    quality: 0.8,
    angle: 0,
    allowsEditing: false,
    noData: false,
    storageOptions: { 
        skipBackup: true, 
        path: 'images'
    }
};

class CameraButton extends React.Component {
    constructor(props){
        super(props);
        this.state = {
            loading:false
        }
    }
    render() {
        const {photos,type} = this.props;
        let conText;
        if(photos.length > 0){
            conText = (<View style={styles.countBox}>
                <Text style={styles.count}>{photos.length}</Text>
            </View>);
        }
        return (
            <TouchableOpacity
                onPress={this.showImagePicker.bind(this)}
                style={[this.props.style,styles.cameraBtn]}>
                <View>
                    <Icon name="md-camera" color="#aaa" size={34}/>
                    {conText}
                </View>
            </TouchableOpacity>
        )
    }

    showImagePicker() {
        ImagePicker.showImagePicker(options, (response) => {
            if (response.didCancel) {
                console.log('User cancelled image picker');
            }
            else if (response.error) {
                console.log('ImagePicker Error: ', response.error);
            }

            else {

                let source;

                if (Platform.OS === 'android') {
                    source = {uri: response.uri, isStatic: true}
                } else {
                    source = {uri: response.uri.replace('file://', ''), isStatic: true}
                }




                let file;
                if(Platform.OS === 'android'){
                    file = response.uri
                }else {
                    file = response.uri.replace('file://', '')
                }


                this.setState({
                    loading:true
                });
                this.props.onFileUpload(file,response.fileName||'未命名文件.jpg')
                .then(result=>{
                    this.setState({
                        loading:false
                    })
                })
            }
        });
    }
}
const styles = StyleSheet.create({
    cameraBtn: {
        padding:5
    },
    count:{
        color:'#fff',
        fontSize:12
    },
    fullBtn:{
        justifyContent:'center',
        alignItems:'center',
        backgroundColor:'#fff'
    },
    countBox:{
        position:'absolute',
        right:-5,
        top:-5,
        alignItems:'center',
        backgroundColor:'#34A853',
        width:16,
        height:16,
        borderRadius:8,
        justifyContent:'center'
    }
});

export default CameraButton;

然后在需要使用的地方引入。

import CameraButton from '../../component/huar/cameraButton'


                    <CameraButton style={styles.cameraBtn}
                                  photos={[]}
                                  onFileUpload={this.onFileUpload} />
点击上传事件：
    onFileUpload(file, fileName){
        return this.props.uploadAvatar({
            id: this.props.user.ID,
            type:'logo',
            obj:'user',
            corpId: this.props.cropId
        }, file, fileName)｝
 Action请求代码：
function actions(dispatch) {
    return {
        fileUrl,fileName)=>dispatch(Actions.uploadAvatar(params, fileUrl,fileName))
    }
}

actions中的uploadAvatar函数如下。

function uploadAvatar(params, fileUrl, fileName) {
    return dispatch=> {
        return UserService.uploadImage(params, fileUrl, fileName)
            .then(result=> {
                dispatch({
                    type: UPDATE_AVATAR,
                    path: result.path
                })
                return result
            })
    }
}

//UserService.uploadImage代码如下
export function uploadImage(params, fileUrl,fileName) {
    return http.uploadFile(`${config.UploadImage}`, params, fileUrl,fileName)
}

UserService函数的http异步上传图片代码如下：

let queryString = require('query-string');
import Storage from './storage'
import {
    Platform
} from 'react-native'

const os = Platform.OS;

async function uploadFile(url, params, fileUrl,fileName) {
    let Access_Token = await Storage.getItem('Access_Token');
    let data = new FormData();

    data.append('file', {
        uri: fileUrl,
        name: fileName,
        type: 'image/jpeg'
    });

    Object.keys(params).forEach((key)=> {
        if (params[key] instanceof Date) {
            data.append(key, value.toISOString())
        } else {
            data.append(key, String(params[key]))
        }
    });

    const fetchOptions = {
        method: 'POST',
        headers: {
            'Accept': 'application/json',
            'Access_Token': Access_Token ? Access_Token : '',
            'UserAgent':os
        },
        body: data
    };


    return fetch(url, fetchOptions)
        .then(checkStatus)
        .then(parseJSON)
}