# 识别本地图片 从API版本26.0.0开始，新增支持图片识码能力。 图片识码能力支持对图库中的码图进行扫描识别，并获取信息。 ## 场景介绍 图片识码能力支持对图库中的条形码、二维码、MULTIFUNCTIONAL CODE进行识别，并获得码类型、码值、码位置等信息。该能力可用于一图单码和一图多码的识别，比如条形码、付款码等。 ## 业务流程 ![](https://contentcenter-vali-drcn.dbankcdn.cn/pvt_2/DeveloperAlliance_scene_100_1/e5/v3/oW962IwkQMeu7mvYFRR7Xw/zh-cn_image_0000002768023662.png?HW-CC-KV=V1&HW-CC-Date=20261026T033631Z&HW-CC-Expire=31536000000&HW-CC-Sign=7AB2EFD92D72E8CDFF5AB5D2E86C85EA7A9A2B9A7E66623A84D95D60C4EBDBAA) 1. 用户向开发者的元服务发起图片识码请求。 2. 元服务通过调用Scan Kit的decode接口启动图片识码。 3. Scan Kit通过回调返回图片识码结果。 4. 元服务向用户返回扫码结果。 ## 接口说明 接口返回值有两种返回形式：Callback和Promise回调。下表中为启动图片识码Callback和Promise形式接口，Callback和Promise只是返回值方式不一样，功能相同。具体API说明详见[接口文档](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/scan-imagedecode)。 |接口名|描述| |:-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:-------------------------------------------------------------------------------| |[decode](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/scan-imagedecode#decode)(inputImage: [InputImage](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/scan-imagedecode#inputimage), options?: scanBarcode.[ScanOptions](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/scan-scanbarcode-api#scanoptions)): Promise>|启动图片识码，通过InputImage传入图片信息、ScanOptions进行识码参数设置（options为可选参数）返回识码结果。使用Promise异步回调。| |[decode](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/scan-imagedecode#decode-1)(inputImage: InputImage, options: scanBarcode.ScanOptions, callback: AsyncCallback>): void|启动图片识码，通过InputImage传入图片信息、ScanOptions进行识码参数设置返回识码结果。使用callback异步回调。| |[decode](https://developer.huawei.com/consumer/cn/doc/harmonyos-references/scan-imagedecode#decode-2)(inputImage: InputImage, callback: AsyncCallback>): void|启动图片识码，通过InputImage传入图片信息返回识码结果。使用callback异步回调。| ## 开发步骤 图片识码接口支持识别图库中的条形码，二维码以及MULTIFUNCTIONAL CODE，并返回图片中码类型，码值、码位置（码图最小外接矩形左上角和右下角的坐标）等信息。 以下示例为调用图片识码的decode接口获取码图信息。 1. 导入图片识码接口和相关接口模块，该接口提供了图片识码参数和方法，导入方法如下。 ```typescript // 导入图片识码需要的日志和PhotoViewPicker模块 import { scanCore, scanBarcode, detectBarcode } from '@kit.ScanKit'; import { photoAccessHelper } from '@kit.MediaLibraryKit'; import { hilog } from '@kit.PerformanceAnalysisKit'; import { BusinessError } from '@kit.BasicServicesKit'; ``` 2. 调用decode接口解析码图。 * 通过Promise回调函数得到扫码结果，InputImage对象中uri参数推荐通过[PhotoViewPicker](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/photoaccesshelper-photoviewpicker)方式获取。 ```typescript @Entry @Component struct DetectPage { build() { Column() { Button('Promise with options') .backgroundColor('#0D9FFB') .fontSize(20) .fontColor($r('sys.color.comp_background_list_card')) .fontWeight(FontWeight.Normal) .align(Alignment.Center) .type(ButtonType.Capsule) .width('90%') .height(40) .margin({ top: 5, bottom: 5 }) .onClick(() => { // 定义识码参数options let options: scanBarcode.ScanOptions = { scanTypes: [scanCore.ScanType.ALL], enableMultiMode: true }; // 通过PhotoViewPicker拉起图库并选择图片 let photoOption = new photoAccessHelper.PhotoSelectOptions(); photoOption.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE; photoOption.maxSelectNumber = 1; let photoPicker = new photoAccessHelper.PhotoViewPicker(); photoPicker.select(photoOption).then((data) => { // 定义识码参数inputImage，其中uri为PhotoViewPicker选择的图片路径 let inputImage: detectBarcode.InputImage = { uri: data.photoUris[0] }; try { // 调用图片识码接口 detectBarcode.decode(inputImage, options).then((data: Array) => { hilog.info(0x0001, '[Scan Sample]', `Succeeded in getting ScanResult by promise with options, result length: ${data.length}`); }).catch((err: BusinessError) => { hilog.error(0x0001, '[Scan Sample]', `Failed to get ScanResult by promise with options. Code: ${err.code}, message: ${err.message}`); }); } catch (err) { hilog.error(0x0001, '[Scan Sample]', `Failed to detectBarcode. Code: ${err.code}, message: ${err.message}`); } }).catch((err: BusinessError) => { hilog.error(0x0001, '[Scan Sample]', `Failed to select a photo. Code: ${err.code}, message: ${err.message}`); }); }) } .width('100%') .height('100%') .alignItems(HorizontalAlign.Center) .justifyContent(FlexAlign.Center) } } ``` * 通过Callback回调函数得到扫码结果，InputImage对象中uri参数推荐通过[PhotoViewPicker](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/photoaccesshelper-photoviewpicker)方式获取。 ```typescript @Entry @Component struct DetectPage { build() { Column() { Button('Callback with options') .backgroundColor('#0D9FFB') .fontSize(20) .fontColor($r('sys.color.comp_background_list_card')) .fontWeight(FontWeight.Normal) .align(Alignment.Center) .type(ButtonType.Capsule) .width('90%') .height(40) .margin({ top: 5, bottom: 5 }) .onClick(() => { // 定义识码参数options let options: scanBarcode.ScanOptions = { scanTypes: [scanCore.ScanType.ALL], enableMultiMode: true, enableAlbum: true }; // 通过PhotoViewPicker拉起图库并选择图片 let photoOption = new photoAccessHelper.PhotoSelectOptions(); photoOption.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE; photoOption.maxSelectNumber = 1; let photoPicker = new photoAccessHelper.PhotoViewPicker(); photoPicker.select(photoOption).then((data) => { // 定义识码参数inputImage，其中uri为PhotoViewPicker选择的图片路径 let inputImage: detectBarcode.InputImage = { uri: data.photoUris[0] }; try { // 调用图片识码接口 detectBarcode.decode(inputImage, options, (err: BusinessError, data: Array) => { if (err && err.code) { hilog.error(0x0001, '[Scan Sample]', `Failed to get ScanResult by callback with options. Code: ${err.code}, message: ${err.message}`); return; } hilog.info(0x0001, '[Scan Sample]', `Succeeded in getting ScanResult by callback with options, result length: ${data.length}`); }); } catch (err) { hilog.error(0x0001, '[Scan Sample]', `Failed to detectBarcode. Code: ${err.code}, message: ${err.message}`); } }).catch((err: BusinessError) => { hilog.error(0x0001, '[Scan Sample]', `Failed to select a photo. Code: ${err.code}, message: ${err.message}`); }); }) } .width('100%') .height('100%') .alignItems(HorizontalAlign.Center) .justifyContent(FlexAlign.Center) } } ``` ## 模拟器开发 支持模拟器开发，模拟器使用指导请参见[使用模拟器运行应用](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/ide-run-emulator)。