React Native使用fetch实现图片上传的示例代码

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
/** 
 * 使用fetch实现图片上传
 * @param {string} url 接口地址
 * @param {JSON} params body的请求参数
 * @return 返回Promise 
 */
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);
 });
 });
}

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
 })