鸿蒙文件上传-从前端到后端详解，对比jq请求和鸿蒙arkts请求区别，对比new FormData()和鸿蒙arktsrequest.uploadFile

需要权限：ohos.permission.INTERNET

1.nodejs自定义书写上传后端接口

传输过来的数据放在files?.image下
在这里插入图片描述

router.post('/upload',(req, res) => {var form = new multiparty.Form();form.uploadDir='public/images/uploads'; //上传图片保存的地址(目录必须存在)form.parse(req, function(err, fields, files) {// 1、fields:获取表单的数据 2、files：图片上传成功返回的信息console.log(files,fields)const fileurl = Date.now()+ files?.image[0]?.originalFilename;let newPath = form.uploadDir + '/' +fileurlfs.renameSync(files.image[0].path,newPath);let imgUrl = myUrl.myUrl+'/images/uploads/' +fileurlres.send({code: '200',message: '数据上传成功',data:imgUrl})})
})

2，在jq中请求(new FormData())

        var fileImg;//读取图片function fileUpload(_this) {var fileReader = new FileReader();//创建文件读取对象fileImg = _this.files[0];//获取file组件中的文件}//上传图片function uploadPictures() {var formData = new FormData();//图片if (fileImg != null) {formData.append("image", fileImg);}$.ajax({url: 'http://localhost:3333/api/img/upload',type: 'post',data: formData,processData: false,contentType: false,success: function (res) {// var res = JSON.parse(res);console.log('upload success', res);// $('.img').attr('src', res.path);debugger},error: function (err) {console.log('upload error', err);console.log(err);}});}

3.对比在鸿蒙arkts请求如下 -试用相册的场景

参考官网

1.假设数据来源于相册，以下是获取相册的数据，photoSelectResult.photoUris[0]是一个目录的路径，但是不是context.cacheDir的路径，

试用下载必须要在cacheDir目录下面

async selectPhoto() {try {let PhotoSelectOptions = new photoAccessHelper.PhotoSelectOptions();PhotoSelectOptions.maxSelectNumber = 1;PhotoSelectOptions.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE;let textInfo: photoAccessHelper.TextContextInfo = {text: '人像'};let recommendationOptions: photoAccessHelper.RecommendationOptions = {textContextInfo: textInfo};PhotoSelectOptions.recommendationOptions =recommendationOptions; // 将推荐参数赋值给 photoSelectOptions.recommendationOptionslet photoPicker = new photoAccessHelper.PhotoViewPicker();let photoSelectResult = await photoPicker.select(PhotoSelectOptions)if (photoSelectResult.photoUris.length == 1) {this.uploadFile(photoSelectResult.photoUris[0])}} catch (error) {let err: BusinessError = error as BusinessError;}}

2.因为必须是cacheDir目录，从相册拿到的的图片就复制一份存在cacheDir

// 提取文件扩展名的函数getFileExtension(fileName: string): string {const lastDotIndex = fileName.lastIndexOf('.');if (lastDotIndex !== -1 && lastDotIndex < fileName.length - 1) {return fileName.slice(lastDotIndex + 1);}return '';}
。。。。。console.log('photoUris', photoUris)const extensionName = this.getFileExtension(photoUris) // 后缀名console.log('文件扩展名是:', extensionName);const cacheDir = context.cacheDir; // 缓存根目录const names = 'phone' + Date.now() + '.' + extensionName // 文件名const cacheF = cacheDir + '/' + names // 缓存目录路径let file: fileIo.File | undefined;file = fileIo.openSync(photoUris, fileIo.OpenMode.READ_ONLY); // 打开现有的文件fileIo.copyFileSync(file.fd, cacheF); //复制一下到缓存文件fileIo.closeSync(file); // 关闭console.log('文件扩展名是:', extensionName, '----', names);

3。知道了cacheDir目录就组装参数

let files: Array<request.File> = [//uri前缀internal://cache 对应cacheDir目录{filename: names,name: 'image',  // 必须是image，因为接口拿的数据就是这个的第0项uri: 'internal://cache/' + names,type: extensionName}]let data: Array = [{ name: 'name', value: 'value' }];let uploadConfig: request.UploadConfig = {url: 'http://xxxxxxxxxxxxxxxx/api/img/upload',header: {// 根据项目添加
},method: 'POST',files: files,data: data,}// 将本地应用文件上传至网络服务器
try {request.uploadFile(context, uploadConfig).then((uploadTask: request.UploadTask) => {let headerCallback = (value: object) => {let str = JSON.stringify(value)console.log("http:success:", JSON.stringify(rstr ))};uploadTask.on('headerReceive', headerCallback);}).catch((err: BusinessError) => {console.error(`Invoke uploadFile failed, code is ${err.code}, message is ${err.message}`);})
} catch (error) {let err: BusinessError = error as BusinessError;console.error(`Invoke uploadFile failed, code is ${err.code}, message is ${err.message}`);
}

缓存目录在cacheDir ="/data/app/el2/100/base/{找到自己的包名}/haps/entry/cache”
在这里插入图片描述

在这里插入图片描述

原理总结

使用相册拿到的路径，复制一份放在缓存路径下， request.uploadFile(只能读缓存的路径。
通过 uploadTask.on(‘headerReceive’, headerCallback);拿到后端给我们的响应数据code

官网也还提供了request.agent，可查看文档使用
https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/app-file-upload-download#%E4%B8%8A%E4%BC%A0%E5%BA%94%E7%94%A8%E6%96%87%E4%BB%B6