【HarmonyOS】鸿蒙使用ScanKit实现自定义扫码 （二）之解析相册图片二维码

【HarmonyOS】鸿蒙使用ScanKit实现自定义扫码 （二）之解析相册图片二维码
一、业务流程：

二、实现思路：
1.从相册中选图，目前最简单的方式是 PhotoPicker
import { photoAccessHelper } from '@kit.MediaLibraryKit';

/**

• 去相册选择图片
  */
  onClickSelectPhoto = ()=>{
  try {
  let PhotoSelectOptions = new photoAccessHelper.PhotoSelectOptions();
  // 设置筛选过滤条件
  PhotoSelectOptions.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE;
  // 选择用户选择数量
  PhotoSelectOptions.maxSelectNumber = 1;
  // 实例化图片选择器
  let photoPicker = new photoAccessHelper.PhotoViewPicker();
  // 唤起安全相册组件
  photoPicker.select(PhotoSelectOptions, (err: BusinessError, PhotoSelectResult: photoAccessHelper.PhotoSelectResult) => {
  if (err) {
  console.error(this.TAG, "onClickSelectPhoto photoPicker.select error:" + JSON.stringify(err));
  return;
  }
  // 用户选择确认后，会回调到这里。
  console.info(this.TAG, "onClickSelectPhoto photoPicker.select successfully:" + JSON.stringify(PhotoSelectResult));

  });
  } catch (error) {
  let err: BusinessError = error as BusinessError;
  console.error(this.TAG, "onClickSelectPhoto photoPicker.select catch failed:" + JSON.stringify(err));
  }
  }

2.将拿到的图片信息给scanKit提供的decode接口进行解析二维码
import { customScan, scanBarcode, scanCore, detectBarcode } from '@kit.ScanKit'

/**

• 解析图片码数据
  */
  private detectPhoto(uri: string){
  if(uri){
  let inputImg: detectBarcode.InputImage = {
  uri: uri,
  };
  let setting: scanBarcode.ScanOptions = {
  scanTypes: [
  scanCore.ScanType.ALL
  ],
  // 开启识别多码
  enableMultiMode: true,
  enableAlbum: true,
  };
  try {
  // 调用图片识码接口
  detectBarcode.decode(inputImg, setting).then((result: Array<scanBarcode.ScanResult>) => {
  console.info(this.TAG, " decode res: " + JSON.stringify(result))

  }).catch((error: BusinessError) => {
  console.error(this.TAG, " decode error: " + JSON.stringify(error))
  });
  } catch (error) {
  console.error(this.TAG, " catch error: " + JSON.stringify(error))
  }
  }else{
  promptAction.showToast({
  message: "图片数据异常！" + uri
  })
  }
  }

3.处理解析结果，图片占位（无码提示，多码绘图用户选择，单码结果处理）【不展开】
三、源码示例：
import { customScan, scanBarcode, scanCore, detectBarcode } from '@kit.ScanKit'
import { hilog } from '@kit.PerformanceAnalysisKit'
import { BusinessError } from '@kit.BasicServicesKit'
import { abilityAccessCtrl, common } from '@kit.AbilityKit'
import { display, promptAction } from '@kit.ArkUI'
import { photoAccessHelper } from '@kit.MediaLibraryKit';

@Builder
export function ScanPageBuilder(name: string, param: object){
if(isLog(name, param)){
ScanPage()
}
}

function isLog(name: string, param: object){
console.log("ScanPageBuilder", " ScanPageBuilder init name: " + name);
return true;
}

@Entry
@Component
export struct ScanPage {
private TAG: string = '[customScanPage]';

@State userGrant: boolean = false // 是否已申请相机权限
@State surfaceId: string = '' // xComponent组件生成id
@State isShowBack: boolean = false // 是否已经返回扫码结果
@State isFlashLightEnable: boolean = false // 是否开启了闪光灯
@State isSensorLight: boolean = false // 记录当前环境亮暗状态
@State cameraHeight: number = 480 // 设置预览流高度，默认单位：vp
@State cameraWidth: number = 300 // 设置预览流宽度，默认单位：vp
@State cameraOffsetX: number = 0 // 设置预览流x轴方向偏移量，默认单位：vp
@State cameraOffsetY: number = 0 // 设置预览流y轴方向偏移量，默认单位：vp
@State zoomValue: number = 1 // 预览流缩放比例
@State setZoomValue: number = 1 // 已设置的预览流缩放比例
@State scaleValue: number = 1 // 屏幕缩放比
@State pinchValue: number = 1 // 双指缩放比例
@State displayHeight: number = 0 // 屏幕高度，单位vp
@State displayWidth: number = 0 // 屏幕宽度，单位vp
@State scanResult: Array<scanBarcode.ScanResult> = [] // 扫码结果
private mXComponentController: XComponentController = new XComponentController()

async onPageShow() {
// 自定义启动第一步，用户申请权限
await this.requestCameraPermission();
// 自定义启动第二步：设置预览流布局尺寸
this.setDisplay();
// 自定义启动第三步，配置初始化接口
this.setScanConfig();
}

private setScanConfig(){
// 多码扫码识别，enableMultiMode: true 单码扫码识别enableMultiMode: false
let options: scanBarcode.ScanOptions = {
scanTypes: [scanCore.ScanType.ALL],
enableMultiMode: true,
enableAlbum: true
}
customScan.init(options);
}

async onPageHide() {
// 页面消失或隐藏时，停止并释放相机流
this.userGrant = false;
this.isFlashLightEnable = false;
this.isSensorLight = false;
try {
customScan.off('lightingFlash');
} catch (error) {
hilog.error(0x0001, this.TAG, Failed to off lightingFlash. Code: ${error.code}, message: ${error.message});
}
await customScan.stop();
// 自定义相机流释放接口
customScan.release().then(() => {
hilog.info(0x0001, this.TAG, 'Succeeded in releasing customScan by promise.');
}).catch((error: BusinessError) => {
hilog.error(0x0001, this.TAG,
Failed to release customScan by promise. Code: ${error.code}, message: ${error.message});
})
}

/**

• 去相册选择图片
  */
  onClickSelectPhoto = ()=>{
  try {
  let PhotoSelectOptions = new photoAccessHelper.PhotoSelectOptions();
  // 设置筛选过滤条件
  PhotoSelectOptions.MIMEType = photoAccessHelper.PhotoViewMIMETypes.IMAGE_TYPE;
  // 选择用户选择数量
  PhotoSelectOptions.maxSelectNumber = 1;
  // 实例化图片选择器
  let photoPicker = new photoAccessHelper.PhotoViewPicker();
  // 唤起安全相册组件
  photoPicker.select(PhotoSelectOptions, (err: BusinessError, PhotoSelectResult: photoAccessHelper.PhotoSelectResult) => {
  if (err) {
  console.error(this.TAG, "onClickSelectPhoto photoPicker.select error:" + JSON.stringify(err));
  return;
  }
  // 用户选择确认后，会回调到这里。
  console.info(this.TAG, "onClickSelectPhoto photoPicker.select successfully:" + JSON.stringify(PhotoSelectResult));
  // 因为设置的选择个数为1，所以直接取0位
  this.detectPhoto(PhotoSelectResult.photoUris[0]);
  });
  } catch (error) {
  let err: BusinessError = error as BusinessError;
  console.error(this.TAG, "onClickSelectPhoto photoPicker.select catch failed:" + JSON.stringify(err));
  }
  }

/**

• 解析图片码数据
  */
  private detectPhoto(uri: string){
  if(uri){
  let inputImg: detectBarcode.InputImage = {
  uri: uri,
  };
  let setting: scanBarcode.ScanOptions = {
  scanTypes: [
  scanCore.ScanType.ALL
  ],
  // 开启识别多码
  enableMultiMode: true,
  enableAlbum: true,
  };
  try {
  // 调用图片识码接口
  detectBarcode.decode(inputImg, setting).then((result: Array<scanBarcode.ScanResult>) => {
  console.info(this.TAG, " decode res: " + JSON.stringify(result))
  // 长度大于0说明有解析结果
  if(result.length > 0){
  // 长达大于1 多码
  // 解析码值结果跳转应用服务页
  this.scanResult = result;
  this.isShowBack = true;

  if(result.length > 1){

  }else{
  this.showScanResult(result[0]);
  }
  }else{
  promptAction.showToast({
  message: "无二维码数据！"
  });
  }
  }).catch((error: BusinessError) => {
  console.error(this.TAG, " decode error: " + JSON.stringify(error))
  });
  } catch (error) {
  console.error(this.TAG, " catch error: " + JSON.stringify(error))
  }
  }else{
  promptAction.showToast({
  message: "图片数据异常！" + uri
  });
  }
  }

/**

• 用户申请权限
• @returns
  */
  async reqPermissionsFromUser(): Promise<number[]> {
  hilog.info(0x0001, this.TAG, 'reqPermissionsFromUser start');
  let context = getContext() as common.UIAbilityContext;
  let atManager = abilityAccessCtrl.createAtManager();
  let grantStatus = await atManager.requestPermissionsFromUser(context, ['ohos.permission.CAMERA']);
  return grantStatus.authResults;
  }

/**

• 用户申请相机权限
  */
  async requestCameraPermission() {
  let grantStatus = await this.reqPermissionsFromUser();
  for (let i = 0; i < grantStatus.length; i++) {
  if (grantStatus[i] === 0) {
  // 用户授权，可以继续访问目标操作
  console.log(this.TAG, "Succeeded in getting permissions.");
  this.userGrant = true;
  }
  }
  }

// 竖屏时获取屏幕尺寸，设置预览流全屏示例
setDisplay() {
// 折叠屏无 or 折叠
if(display.getFoldStatus() == display.FoldStatus.FOLD_STATUS_UNKNOWN || display.getFoldStatus() == display.FoldStatus.FOLD_STATUS_FOLDED){
// 默认竖屏
let displayClass = display.getDefaultDisplaySync();
this.displayHeight = px2vp(displayClass.height);
this.displayWidth = px2vp(displayClass.width);

}else{
// 折叠屏展开 or 半展开
let displayClass = display.getDefaultDisplaySync();
let tempHeight = px2vp(displayClass.height);
let tempWidth = px2vp(displayClass.width);
console.info("debugDisplay", 'tempHeight: ' + tempHeight + " tempWidth: " + tempWidth);
this.displayHeight = tempHeight + px2vp(8);
this.displayWidth = ( tempWidth - px2vp(64) ) / 2;

}
console.info("debugDisplay", 'final displayHeight: ' + this.displayHeight + " displayWidth: " + this.displayWidth);

let maxLen: number = Math.max(this.displayWidth, this.displayHeight);
let minLen: number = Math.min(this.displayWidth, this.displayHeight);
const RATIO: number = 16 / 9;
this.cameraHeight = maxLen;
this.cameraWidth = maxLen / RATIO;
this.cameraOffsetX = (minLen - this.cameraWidth) / 2;
}

// toast显示扫码结果
async showScanResult(result: scanBarcode.ScanResult) {
// 使用toast显示出扫码结果
promptAction.showToast({
message: JSON.stringify(result),
duration: 5000
});
}

/**

• 启动相机
  */
  private startCamera() {
  this.isShowBack = false;
  this.scanResult = [];
  let viewControl: customScan.ViewControl = {
  width: this.cameraWidth,
  height: this.cameraHeight,
  surfaceId : this.surfaceId
  };
  // 自定义启动第四步，请求扫码接口，通过Promise方式回调
  try {
  customScan.start(viewControl)
  .then(async (result: Array<scanBarcode.ScanResult>) => {
  console.error(this.TAG, 'result: ' + JSON.stringify(result));
  if (result.length) {
  // 解析码值结果跳转应用服务页
  this.scanResult = result;
  this.isShowBack = true;
  // 获取到扫描结果后暂停相机流
  try {
  customScan.stop().then(() => {
  console.info(this.TAG, 'Succeeded in stopping scan by promise ');
  }).catch((error: BusinessError) => {
  console.error(this.TAG, 'Failed to stop scan by promise err: ' + JSON.stringify(error));
  });
  } catch (error) {
  console.error(this.TAG, 'customScan.stop err: ' + JSON.stringify(error));
  }

  }
  }).catch((error: BusinessError) => {
  console.error(this.TAG, 'customScan.start err: ' + JSON.stringify(error));
  });
  } catch (err) {
  console.error(this.TAG, 'customScan.start err: ' + JSON.stringify(err));
  }
  }

/**

• 注册闪光灯监听接口
  */
  private setFlashLighting(){
  customScan.on('lightingFlash', (error, isLightingFlash) => {
  if (error) {
  console.info(this.TAG, "customScan lightingFlash error: " + JSON.stringify(error));
  return;
  }
  if (isLightingFlash) {
  this.isFlashLightEnable = true;
  } else {
  if (!customScan?.getFlashLightStatus()) {
  this.isFlashLightEnable = false;
  }
  }
  this.isSensorLight = isLightingFlash;
  });
  }

// 自定义扫码界面的顶部返回按钮和扫码提示
@Builder
TopTool() {
Column() {
Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.SpaceBetween, alignItems: ItemAlign.Center }) {
Text('返回')
.onClick(async () => {
// router.back();
this.mNavContext?.pathStack.removeByName("ScanPage");
})
}.padding({ left: 24, right: 24, top: 40 })

Column() {
Text('扫描二维码/条形码')
Text('对准二维码/条形码，即可自动扫描')
}.margin({ left: 24, right: 24, top: 24 })
}
.height(146)
.width('100%')
}

@Builder ScanKitView(){
XComponent({
id: 'componentId',
type: XComponentType.SURFACE,
controller: this.mXComponentController
})
.onLoad(async () => {

// 获取XComponent组件的surfaceId
this.surfaceId = this.mXComponentController.getXComponentSurfaceId();
console.info(this.TAG, "Succeeded in getting surfaceId: " + this.surfaceId);

this.startCamera();
this.setFlashLighting();

})
.width(this.cameraWidth)
.height(this.cameraHeight)
.position({ x: this.cameraOffsetX, y: this.cameraOffsetY })
}

@Builder ScanView(){
Stack() {

Column() {
if (this.userGrant) {
this.ScanKitView()
}
}
.height('100%')
.width('100%')
.backgroundColor(Color.Red)

Column() {
this.TopTool()
Column() {
}
.layoutWeight(1)
.width('100%')

Column() {
Row() {
// 闪光灯按钮，启动相机流后才能使用
Button('FlashLight')
.onClick(() => {
// 根据当前闪光灯状态，选择打开或关闭闪关灯
if (customScan.getFlashLightStatus()) {
customScan.closeFlashLight();
setTimeout(() => {
this.isFlashLightEnable = this.isSensorLight;
}, 200);
} else {
customScan.openFlashLight();
}
})
.visibility((this.userGrant && this.isFlashLightEnable) ? Visibility.Visible : Visibility.None)

// 扫码成功后，点击按钮后重新扫码
Button('ReScan')
.onClick(() => {
try {
customScan.rescan();
} catch (error) {
console.error(this.TAG, 'customScan.rescan err: ' + JSON.stringify(error));
}

// 点击按钮重启相机流，重新扫码
this.startCamera();
})
.visibility(this.isShowBack ? Visibility.Visible : Visibility.None)

// 选择相册图片解析二维码
Button('相册')
.onClick(() => {
this.onClickSelectPhoto();
})
}

Row() {
// 预览流设置缩放比例
Button('缩放比例,当前比例:' + this.setZoomValue)
.onClick(() => {
// 设置相机缩放比例
if (!this.isShowBack) {
if (!this.zoomValue || this.zoomValue === this.setZoomValue) {
this.setZoomValue = customScan.getZoom();
} else {
this.zoomValue = this.zoomValue;
customScan.setZoom(this.zoomValue);
setTimeout(() => {
if (!this.isShowBack) {
this.setZoomValue = customScan.getZoom();
}
}, 1000);
}
}
})
}
.margin({ top: 10, bottom: 10 })

Row() {
// 输入要设置的预览流缩放比例
TextInput({ placeholder: '输入缩放倍数' })
.type(InputType.Number)
.borderWidth(1)
.backgroundColor(Color.White)
.onChange(value => {
this.zoomValue = Number(value);
})
}
}
.width('50%')
.height(180)
}

// 单码、多码扫描后，显示码图蓝点位置。点击toast码图信息
ForEach(this.scanResult, (item: scanBarcode.ScanResult, index: number) => {
if (item.scanCodeRect) {
Image($r("app.media.icon_select_dian"))
.width(20)
.height(20)
.markAnchor({ x: 20, y: 20 })
.position({
x: (item.scanCodeRect.left + item?.scanCodeRect?.right) / 2 + this.cameraOffsetX,
y: (item.scanCodeRect.top + item?.scanCodeRect?.bottom) / 2 + this.cameraOffsetY
})
.onClick(() => {
this.showScanResult(item);
})
}
})
}
// 建议相机流设置为全屏
.width('100%')
.height('100%')
.onClick((event: ClickEvent) => {
// 是否已扫描到结果
if (this.isShowBack) {
return;
}
// 点击屏幕位置，获取点击位置(x,y)，设置相机焦点
let x1 = vp2px(event.displayY) / (this.displayHeight + 0.0);
let y1 = 1.0 - (vp2px(event.displayX) / (this.displayWidth + 0.0));
customScan.setFocusPoint({ x: x1, y: y1 });
hilog.info(0x0001, this.TAG, Succeeded in setting focusPoint x1: ${x1}, y1: ${y1});
// 设置连续自动对焦模式
setTimeout(() => {
customScan.resetFocus();
}, 200);
}).gesture(PinchGesture({ fingers: 2 })
.onActionStart((event: GestureEvent) => {
hilog.info(0x0001, this.TAG, 'Pinch start');
})
.onActionUpdate((event: GestureEvent) => {
if (event) {
this.scaleValue = event.scale;
}
})
.onActionEnd((event: GestureEvent) => {
// 是否已扫描到结果
if (this.isShowBack) {
return;
}
// 获取双指缩放比例，设置变焦比
try {
let zoom = customScan.getZoom();
this.pinchValue = this.scaleValue * zoom;
customScan.setZoom(this.pinchValue);
hilog.info(0x0001, this.TAG, 'Pinch end');
} catch (error) {
hilog.error(0x0001, this.TAG, Failed to setZoom. Code: ${error.code}, message: ${error.message});
}
}))
}

private mNavContext: NavDestinationContext | null = null;

build() {
NavDestination(){
this.ScanView()
}
.width("100%")
.height("100%")
.hideTitleBar(true)
.onReady((navContext: NavDestinationContext)=>{
this.mNavContext = navContext;
})
.onShown(()=>{
this.onPageShow();
})
.onHidden(()=>{
this.onPageHide();
})
}
}