HarmonyOS 鸿蒙Next PackingOption中quality数字取值范围及压缩程度定义 HarmonyOS 鸿蒙Next中PackingOption的quality数字0到100表示压缩程度如何确定？因图片上传需小图，但用户图片大小不定，故需根据选中图片大小调整

photoSelect() { const photoSelectOptions = new picker.PhotoSelectOptions(); photoSelectOptions.MIMEType = picker.PhotoViewMIMETypes.IMAGE_TYPE; photoSelectOptions.maxSelectNumber = 5;

const photoPicker = new picker.PhotoViewPicker();
photoPicker.select(photoSelectOptions)
    .then(async (photoSelectResult) => {
        let uri = photoSelectResult.photoUris[0]
        let file = fs.openSync(uri, fs.OpenMode.READ_ONLY)
        this.compressPictures(file)

    })

}

compressPictures(file: fs.File, data?: ArrayBuffer, size: number = 500, quality: number = 99): void | ArrayBuffer { if (data) { const currentSize = data.byteLength / 1024 if (currentSize <= size || quality === 1) { return data } } const imagePackerApi = image.createImagePacker(); const imageSourceApi = image.createImageSource(file.fd); let packOpts: image.PackingOption = { format: “image/jpeg”, quality: quality }

imagePackerApi.packing(imageSourceApi, packOpts)
    .then((ret: ArrayBuffer) => {
        if (data && ret.byteLength === data.byteLength) {
            return ret
        }
        return this.compressPictures(file, ret, size, quality - 1)
    }).catch((err: BusinessError) => {
        console.log(lbh)
        return false
    })

}