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,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,fileName)
            .then(result=> {
                dispatch({
                    type: UPDATE_AVATAR,path: result.path
                })
                return result
            })
    }
}
 //UserService.uploadImage代码如下
export function uploadImage(params,fileName) {
    return http.uploadFile(`${config.UploadImage}`,params,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,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) }

封装上传

如果上面的实现看的比较复杂，那么我们做如下的封装：

let common_url = 'http://192.168.1.1:8080/';  //服务器地址
let token = '';   //用户登陆后返回的token

function uploadImage(url,params){
    return new Promise(function (resolve,reject) {
        let formData = new FormData();
        for (var key in params){
            formData.append(key,params[key]);
        }
        let file = {uri: params.path,type: 'application/octet-stream',name: 'image.jpg'};
        formData.append("file",file);
        fetch(common_url + url,{
            method: 'POST',headers: {
                'Content-Type': 'multipart/form-data;charset=utf-8',"x-access-token": token,},body: formData,}).then((response) => response.json()) .then((responseData)=> { console.log('uploadImage',responseData); resolve(responseData); }) .catch((err)=> { console.log('err',err); reject(err); }); }); }

然后在使用的地方：

let params = {
    userId:'abc12345',//用户id
    path:'file:///storage/emulated/0/Pictures/image.jpg'    //本地文件地址
}
uploadImage('app/uploadFile',params )
    .then( res=>{
        //请求成功
        if(res.header.statusCode == 'success'){
            //这里设定服务器返回的header中statusCode为success时数据返回成功
            upLoadImgUrl = res.body.imgurl;  //服务器返回的地址
        }else{
             //服务器返回异常，设定服务器返回的异常信息保存在 header.msgArray[0].desc
            console.log(res.header.msgArray[0].desc); } }).catch( err=>{ //请求失败 })

附：http://lib.csdn.net/article/reactnative/58022?knId=1415
使用fetch+formData实现图片上传