HarmonyOS 全屏预览时没有合适的photoProfiles和previewProfiles尺寸可选？

Question

竖屏状态下，手机的宽/高为：1260/2720，因为 profiles 的宽高是相反的，可以选择合适的预览值横屏状态下，手机的宽/高为：2720/1260，所有的profiles中几乎都是高大于宽，所以没有合适的 profiles可以选择。

测试了系统相机，在竖屏全屏的情况下，输出的图片为：1888x4096，这个可以和photoProfiles其中的一个对应，在横屏全屏的情况下，输出的图片为：2336x1080，这个没有相应的photoProfiles与之对应，请问这个是怎么做到可以输出宽大于高的图片的呢？

previewProfiles所有的size 如下：

[{"format":1003,"size":{"width":640,"height":480}},{"format":1003,"size":{"width":640,"height":640}},{"format":1003,"size":{"width":864,"height":480}},{"format":1003,"size":{"width":1088,"height":1080}},{"format":1003,"size":{"width":1088,"height":1088}},{"format":1003,"size":{"width":1136,"height":480}},{"format":1003,"size":{"width":1280,"height":592}},{"format":1003,"size":{"width":1280,"height":720}},{"format":1003,"size":{"width":1280,"height":960}},{"format":1003,"size":{"width":1440,"height":1080}},{"format":1003,"size":{"width":1920,"height":1080}},{"format":1003,"size":{"width":1920,"height":1440}},{"format":1003,"size":{"width":2048,"height":1536}},{"format":1003,"size":{"width":2336,"height":1080}},{"format":1003,"size":{"width":2560,"height":1080}},{"format":1003,"size":{"width":2592,"height":1944}}]

photoProfiles所有的size如下：

[{"format":2000,"size":{"width":640,"height":480}},{"format":2000,"size":{"width":640,"height":640}},{"format":2000,"size":{"width":864,"height":480}},{"format":2000,"size":{"width":1088,"height":1088}},{"format":2000,"size":{"width":1136,"height":480}},{"format":2000,"size":{"width":1280,"height":592}},{"format":2000,"size":{"width":1280,"height":720}},{"format":2000,"size":{"width":1280,"height":960}},{"format":2000,"size":{"width":1440,"height":1080}},{"format":2000,"size":{"width":1920,"height":1080}},{"format":2000,"size":{"width":1920,"height":1440}},{"format":2000,"size":{"width":2048,"height":1536}},{"format":2000,"size":{"width":2336,"height":1080}},{"format":2000,"size":{"width":2560,"height":1080}},{"format":2000,"size":{"width":2592,"height":1944}},{"format":2000,"size":{"width":3072,"height":3072}},{"format":2000,"size":{"width":3120,"height":3120}},{"format":2000,"size":{"width":3264,"height":2448}},{"format":2000,"size":{"width":3840,"height":2160}},{"format":2000,"size":{"width":4096,"height":1760}},{"format":2000,"size":{"width":4096,"height":1888}},{"format":2000,"size":{"width":4096,"height":2304}},{"format":2000,"size":{"width":4096,"height":3072}},{"format":2000,"size":{"width":8192,"height":6144}}]

Answer 1

参考demo：

import { camera } from '@kit.CameraKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { image } from '@kit.ImageKit';
import { photoAccessHelper } from '@kit.MediaLibraryKit';
import { abilityAccessCtrl, PermissionRequestResult, Permissions } from '@kit.AbilityKit';
import { display, promptAction } from '@kit.ArkUI';
import { fileIo } from '@kit.CoreFileKit';
import fs from '@ohos.file.fs';
const TAG = '[CameraDemo]';
@Entry
@Component
struct CameraDemo {
  context: Context = getContext(this) as Context;
  @State pixelMap: image.PixelMap | undefined = undefined;
  @State finalPixelMap: image.PixelMap | undefined = undefined;
  @State buffer: ArrayBuffer | undefined = undefined;
  @State surfaceId: string = '';
  @State hasPicture: boolean = false;
  @State fileNames: string[] = [];
  @State imageSize: image.Size = { width: 4160, height: 1920 };
  @State saveButtonOptions: SaveButtonOptions = {
    icon: SaveIconStyle.FULL_FILLED,
    text: SaveDescription.SAVE_IMAGE,
    buttonType: ButtonType.Capsule
  } // 设置安全控件按钮属性
  private mXComponentController: XComponentController = new XComponentController;
  private cameraManager: camera.CameraManager | undefined = undefined;
  private cameraSession: camera.PhotoSession | undefined = undefined;
  private photoOutput: camera.PhotoOutput | undefined = undefined;
  private cameraInput: camera.CameraInput | undefined = undefined;
  private previewOutput: camera.PreviewOutput | undefined = undefined;
  private previewOutput2: camera.PreviewOutput | undefined = undefined;
  private imageReceiver: image.ImageReceiver | undefined = undefined;
  @State ca :Number  = 1
  @State screenWidth :number  = 0
  @State screenHeight :number  = 0

  aboutToAppear(): void {
    let permissions: Array<Permissions> = [
      'ohos.permission.CAMERA',
      'ohos.permission.WRITE_MEDIA',
      'ohos.permission.READ_MEDIA',
      'ohos.permission.MEDIA_LOCATION',
    ];
    let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager();
    // requestPermissionsFromUser会判断权限的授权状态来决定是否唤起弹窗
    atManager.requestPermissionsFromUser(this.context, permissions).then((data: PermissionRequestResult) => {
      let grantStatus: Array<number> = data.authResults;
      let length: number = grantStatus.length;
      for (let i = 0; i < length; i++) {
        if (grantStatus[i] != 0) {
          // 用户拒绝授权，提示用户必须授权才能访问当前页面的功能，并引导用户到系统设置中打开相应的权限
          return;
        }
      }
      console.info(`${TAG} Success to request permissions from user. authResults is ${grantStatus}.`);
    }).catch((err: BusinessError) => {
      console.error(`${TAG} Failed to request permissions from user. Code is ${err.code}, message is ${err.message}`);
    })
    let displaydef = display.getDefaultDisplaySync()
    this.screenWidth = displaydef.width
    this.screenHeight = displaydef.height
  }
  createCameraManager() {
    // 创建CameraManager对象
    let cameraManager: camera.CameraManager = camera.getCameraManager(this.context);
    if (!cameraManager) {
      console.error('CameraDemo camera.getCameraManager error');
      return;
    }
    this.cameraManager = cameraManager;
    // 监听相机状态变化
    this.cameraManager.on('cameraStatus', (err: BusinessError, cameraStatusInfo: camera.CameraStatusInfo) => {
      console.info(`CameraDemo camera: ${cameraStatusInfo.camera.cameraId}, status: ${cameraStatusInfo.status}`);
    });
  }
  async onPageShow(){
    await this.prepareCamera(this.ca);
  }
  build() {
    Stack({alignContent: Alignment.BottomStart}) {
      XComponent({
        id: '',
        type: 'surface',
        libraryname: '',
        controller: this.mXComponentController
      })
        .expandSafeArea([SafeAreaType.SYSTEM], [SafeAreaEdge.TOP, SafeAreaEdge.BOTTOM])
        .onLoad(() => {
          let displaydef = display.getDefaultDisplaySync()
          this.mXComponentController.setXComponentSurfaceRect({offsetX:0,offsetY:0, surfaceWidth: displaydef.height * 1920.0/4160.0, surfaceHeight: displaydef.height});
          //this.mXComponentController.setXComponentSurfaceRect({offsetX:0,offsetY:0, surfaceWidth: this.screenHeight*1080.0/1920.0, surfaceHeight: this.screenHeight });
          this.surfaceId = this.mXComponentController.getXComponentSurfaceId();
          setTimeout(async () => {
            await this.prepareCamera(this.ca);
          }, 500);
        })
        .width('100%')
        .height('100%')
      Row(){
        Button('前置摄像头')
          .size({ width: 100, height: 30 }).margin({ right: 10 })
          .onClick(async () => {
            this.ca=1
            console.debug('打开前置摄像头')
            await this.prepareCamera(this.ca);
          })
        Button('拍照').width(60).height(60).margin({ right: 10 }).borderRadius(30)
          .onClick(async () => {
            let photoCaptureSetting: camera.PhotoCaptureSetting = {
              quality: camera.QualityLevel.QUALITY_LEVEL_HIGH, // 设置图片质量高
              rotation: camera.ImageRotation.ROTATION_0, // 设置图片旋转角度0
              mirror: true // 开启镜像
            }
            // 1、通过拍照流实现：点击拍照
            await this.photoOutput?.capture(photoCaptureSetting).catch((error: BusinessError) => {
              console.error(`CameraDemo Failed to capture the photo ${error.message}`); //不符合条件则进入
            })
            this.hasPicture = true;
          })
        Button('后置摄像头')
          .size({ width: 100, height: 30 }).margin({ left: 10 })
          .onClick(async () => {
            this.ca=0
            console.debug('打开后置摄像头')
            await this.prepareCamera(this.ca);
          })
      }
      .width('100%')
      .justifyContent(FlexAlign.SpaceAround)

      if (this.hasPicture) {
        Image(this.finalPixelMap)
          //.objectFit(ImageFit.Fill)
          .width('100%')
          .height('100%')
          .expandSafeArea([SafeAreaType.SYSTEM], [SafeAreaEdge.TOP, SafeAreaEdge.BOTTOM])
        Row() {
          Button('取消')
            .onClick(() => {
              this.hasPicture = false;
              this.finalPixelMap = undefined;
            })
          SaveButton(this.saveButtonOptions)// 创建安全控件按钮
            .onClick(async (event, result: SaveButtonOnClickResult) => {
              if (result == SaveButtonOnClickResult.SUCCESS) {
                if (this.finalPixelMap) {
                  try {
                    // 1、使用安全控件创建文件
                    let phAccessHelper: photoAccessHelper.PhotoAccessHelper = photoAccessHelper.getPhotoAccessHelper(this.context);
                    let filename = Date.now().toString();
                    let options: photoAccessHelper.CreateOptions = {
                      title: filename
                    };
                    // createAsset的调用需要ohos.permission.READ_IMAGEVIDEO和ohos.permission.WRITE_IMAGEVIDEO的权限
                    let photoUri: string = await phAccessHelper.createAsset(photoAccessHelper.PhotoType.IMAGE, 'png', options);
                    console.info('CameraDemo createAsset successfully, photoUri: ' + photoUri);
                    let file: fileIo.File = fileIo.openSync(photoUri, fileIo.OpenMode.WRITE_ONLY);
                    fileIo.writeSync(file.fd, this.buffer);
                    fileIo.closeSync(file);
                    promptAction.showToast({message: `保存成功`})
                  } catch (error) {
                    let err = error as BusinessError;
                    console.error(`CameraDemo savePicture error: ${JSON.stringify(err)}`);
                    promptAction.showToast({ message: `保存失败` })
                  }
                }
              } else {
                console.error('CameraDemo SaveButtonOnClickResult createAsset failed.');
                promptAction.showToast({ message: `保存失败` })
              }
              setTimeout(() => {
                this.hasPicture = false;
                this.finalPixelMap = undefined;
              }, 1000)
            })
        }
      } else {
      }
    }
    .width('100%')
    .height('100%')
  }
  async prepareCamera(ca:Number) {
    this.releaseCamera()
    this.createCameraManager();
    if (!this.cameraManager) {
      console.error('CameraDemo cameraManager is undefined.')
      return;
    }
    // 获取支持指定的相机设备对象
    let cameraDevices: Array<camera.CameraDevice> = [];
    let CameraDevice:camera.CameraDevice
    try {
      cameraDevices = this.cameraManager.getSupportedCameras();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo The getSupportedCameras call failed. error: ${JSON.stringify(err)}`)
    }
    cameraDevices.forEach((cameraDevice: camera.CameraDevice) => {
      console.info(`CameraDemo cameraId: ${cameraDevice.cameraId}, cameraPosition: ${cameraDevice.cameraPosition.toString()}, cameraType: ${cameraDevice.cameraType.toString()}, connectionType: ${cameraDevice.connectionType.toString()}`)
    })
    // 创建相机输入流
    try {
      if (ca==0) {
        CameraDevice = cameraDevices[0]
      }else {
        CameraDevice = cameraDevices[1]
      }
      this.cameraInput = this.cameraManager.createCameraInput(CameraDevice);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createCaptureSession error. error: ${JSON.stringify(err)}`);
      return
    }
    // 监听cameraInput错误信息
    this.cameraInput.on('error', CameraDevice, (error: BusinessError) => {
      console.error(`CameraDemo Camera input error: ${JSON.stringify(error)}`);
    });
    // 打开相机
    try {
      await this.cameraInput.open();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo cameraInput open error. error: ${JSON.stringify(err)}`);
    }
    // 获取指定的相机设备对象支持的模式
    let cameraSceneModes: Array<camera.SceneMode> = [];
    try {
      cameraSceneModes = this.cameraManager.getSupportedSceneModes(CameraDevice);
      cameraSceneModes.forEach((cameraSceneMode: camera.SceneMode) => {
        console.info(`CameraDemo cameraSceneMode: ${cameraSceneMode.toString()}`)
      })
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo The getSupportedSceneModes call failed. error: ${JSON.stringify(err)}`)
    }
    // 获取相机设备支持的输出流能力
    let cameraOutputCapability: camera.CameraOutputCapability = this.cameraManager.getSupportedOutputCapability(CameraDevice, camera.SceneMode.NORMAL_PHOTO)
    if (!cameraOutputCapability) {
      console.error('CameraDemo cameraManager.getSupportedOutputCapability error');
      return;
    }
    this.printCameraOutputCapability(cameraOutputCapability);
    let previewProfile = cameraOutputCapability.previewProfiles[0];
    cameraOutputCapability.previewProfiles.forEach((profile) => {
      if (profile.size.width == this.imageSize.width && profile.size.height == this.imageSize.height) {
        previewProfile = profile;
        return;
      }
    })
    this.imageSize = previewProfile.size;
    // 创建相机预览输出流
    try {
      this.previewOutput = this.cameraManager.createPreviewOutput(previewProfile, this.surfaceId);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createCaptureSession error. error: ${JSON.stringify(err)}`);
      return
    }
    // 监听previewOutput错误信息
    this.previewOutput.on('error', (error: BusinessError) => {
      console.error(`CameraDemo previewOutput error: ${JSON.stringify(error)}`);
    });
    //双路预览: 创建 预览流2 输出对象
    try {
      this.imageReceiver = image.createImageReceiver(this.imageSize, image.ImageFormat.JPEG, 8);
      let imageReceiverSurfaceId: string = await this.imageReceiver.getReceivingSurfaceId()
      this.previewOutput2 = this.cameraManager.createPreviewOutput(previewProfile, imageReceiverSurfaceId);
      this.onImageArrival(this.imageReceiver);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createImageReceiver error ${JSON.stringify(err)}`);
      return
    }
    // 创建拍照输出流
    try {
      let photoProfile = cameraOutputCapability.photoProfiles[0];
      cameraOutputCapability.photoProfiles.forEach((profile) => {
        if (profile.size.width == this.imageSize.width && profile.size.height == this.imageSize.height) {
          photoProfile = profile;
          return;
        }
      })
      this.photoOutput = this.cameraManager.createPhotoOutput(photoProfile);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createPhotoOutput error ${JSON.stringify(err)}`);
    }
    if (this.photoOutput === undefined) {
      console.error('CameraDemo photoOutput is undefined.');
      return;
    }
    //调用上面的回调函数来保存图片
    this.setPhotoOutputCb(this.photoOutput);
    // 创建相机会话
    try {
      // this.cameraSession = this.cameraManager.createCaptureSession();
      this.cameraSession = this.cameraManager.createSession<camera.PhotoSession>(camera.SceneMode.NORMAL_PHOTO);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo createCaptureSession error. error: ${JSON.stringify(err)}`);
      return
    }
    // 监听session错误信息
    this.cameraSession.on('error', (error: BusinessError) => {
      console.error(`CameraDemo Capture session error: ${JSON.stringify(error)}`);
    });
    // 开始会话配置
    try {
      this.cameraSession.beginConfig()
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo beginConfig error. error: ${JSON.stringify(err)}`);
    }
    // 向会话中添加相机输入流
    try {
      this.cameraSession.addInput(this.cameraInput)
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo addInput error. error: ${JSON.stringify(err)}`);
    }
    // 向会话中添加预览输出流
    try {
      this.cameraSession.addOutput(this.previewOutput)
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo add previewOutput error. error: ${JSON.stringify(err)}`);
    }
    // 向会话中添加预览输出流2
    try {
      this.cameraSession.addOutput(this.previewOutput2)
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo add previewOutput2 error. error: ${JSON.stringify(err)}`);
    }
    // 向会话中添加拍照输出流
    try {
      this.cameraSession.addOutput(this.photoOutput);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo add photoOutput error. error: ${JSON.stringify(err)}`);
    }
    // 提交会话配置
    try {
      await this.cameraSession.commitConfig();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo captureSession commitConfig error: ${JSON.stringify(err)}`);
    }
    // 启动会话
    try {
      await this.cameraSession.start();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo captureSession start error: ${JSON.stringify(err)}`);
    }
    // 配置相机的参数可以调整拍照的一些功能，包括闪光灯、变焦、焦距等。
    this.configuringSession(this.cameraSession)
  }
  configuringSession(photoSession: camera.PhotoSession): void {
    // 判断设备是否支持闪光灯
    let flashStatus: boolean = false;
    try {
      flashStatus = photoSession.hasFlash();
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to hasFlash. error: ${JSON.stringify(err)}`);
    }
    console.info(`CameraDemo Returned with the flash light support status: ${flashStatus}`);
    if (flashStatus) {
      // 判断是否支持自动闪光灯模式
      let flashModeStatus: boolean = false;
      try {
        let status: boolean = photoSession.isFlashModeSupported(camera.FlashMode.FLASH_MODE_AUTO);
        flashModeStatus = status;
      } catch (error) {
        let err = error as BusinessError;
        console.error(`CameraDemo Failed to check whether the flash mode is supported. error: ${JSON.stringify(err)}`);
      }
      if (flashModeStatus) {
        // 设置自动闪光灯模式
        try {
          photoSession.setFlashMode(camera.FlashMode.FLASH_MODE_AUTO);
        } catch (error) {
          let err = error as BusinessError;
          console.error(`CameraDemo Failed to set the flash mode. error: ${JSON.stringify(err)}`);
        }
      }
    }
    // 判断是否支持连续自动变焦模式
    let focusModeStatus: boolean = false;
    try {
      let status: boolean = photoSession.isFocusModeSupported(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
      focusModeStatus = status;
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to check whether the focus mode is supported. error: ${JSON.stringify(err)}`);
    }
    if (focusModeStatus) {
      // 设置连续自动变焦模式
      try {
        photoSession.setFocusMode(camera.FocusMode.FOCUS_MODE_CONTINUOUS_AUTO);
      } catch (error) {
        let err = error as BusinessError;
        console.error(`CameraDemo Failed to set the focus mode. error: ${JSON.stringify(err)}`);
      }
    }
    // 获取相机支持的可变焦距比范围
    let zoomRatioRange: Array<number> = [];
    try {
      zoomRatioRange = photoSession.getZoomRatioRange();
      zoomRatioRange.forEach(( index: number) => {
        console.info(`zoomRatioRange 支持的焦距: [${index}]`);
      })
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to get the zoom ratio range. error: ${JSON.stringify(err)}`);
    }
    if (zoomRatioRange.length <= 0) {
      return;
    }
    // 设置可变焦距比
    try {
      photoSession.setZoomRatio(1);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`CameraDemo Failed to set the zoom ratio value. error: ${JSON.stringify(err)}`);
    }
  }

  // 通过Surface进行数据传递，通过ImageReceiver的surface获取预览图像。
  async onImageArrival(receiver: image.ImageReceiver): Promise<void> {
    receiver.on('imageArrival', () => {
      receiver.readNextImage(async (err, nextImage: image.Image) => {
        //console.info(`enter CameraDemo imageArrival, nextImage: ${JSON.stringify(nextImage)}`)
        if (err || nextImage === undefined) {
          console.error(`CameraDemo imageArrival error, error is ${JSON.stringify(err)} or nextImage is undefined`)
          return;
        }
        nextImage.getComponent(image.ComponentType.JPEG, async (err, imgComponent: image.Component) => {
          if (err || imgComponent === undefined) {
            console.error(`CameraDemo getComponent error, error is ${JSON.stringify(err)} or imgComponent is undefined`)
            return;
          }
          if (imgComponent.byteBuffer as ArrayBuffer) {
            let sourceOptions: image.SourceOptions = {
              sourceDensity: 0,
              sourcePixelFormat: image.PixelMapFormat.NV12, // NV21
              sourceSize: this.imageSize
            }
            let imageSource: image.ImageSource = image.createImageSource(imgComponent.byteBuffer, sourceOptions);
            let opts: image.InitializationOptions = {
              editable: false,
              pixelFormat: image.PixelMapFormat.NV21,
              size: this.imageSize
            }
            let pixelMap = await imageSource.createPixelMap(opts);
            await pixelMap.rotate(270.0);
            this.pixelMap = pixelMap;
            await imageSource.release();
          } else {
            return;
          }
          nextImage.release()
        })
      })
    })
  }

  setPhotoOutputCb(photoOutput: camera.PhotoOutput) {
    //设置回调之后，调用photoOutput的capture方法，就会将拍照的buffer回传到回调中
    photoOutput.on('photoAvailable', (errCode: BusinessError, photo: camera.Photo): void => {
      console.info(`CameraDemo getPhoto start. err: ${JSON.stringify(errCode)}`);
      if (errCode || photo === undefined || photo.main === undefined) {
        console.error('CameraDemo getPhoto failed');
        return;
      }
      let imageObj = photo.main;
      imageObj.getComponent(image.ComponentType.JPEG, async (errCode: BusinessError, component: image.Component): Promise<void> => {
        console.info('CameraDemo getComponent start');
        if (errCode || component === undefined) {
          console.error('CameraDemo getComponent failed');
          return;
        }
        let buffer: ArrayBuffer;
        if (component.byteBuffer) {
          buffer = component.byteBuffer;
          this.buffer = buffer;
          let sourceOptions: image.SourceOptions = {
            sourceDensity: 0, // 在不确定当前密度时传0
            sourcePixelFormat: image.PixelMapFormat.RGBA_8888,
            sourceSize: this.imageSize
          }
          let imageSource: image.ImageSource = image.createImageSource(buffer, sourceOptions);
          let opts: image.InitializationOptions = {
            editable: false,
            pixelFormat: image.PixelMapFormat.RGBA_8888,
            size: this.imageSize
          }
          let pixelMap = await imageSource.createPixelMap(opts);
          this.finalPixelMap = pixelMap;
        } else {
          console.error('CameraDemo byteBuffer is null');
          return;
        }
      });
    });
  }
  releaseCamera() {
    if (this.cameraInput) {
      this.cameraInput.close()
    }
    if (this.previewOutput) {
      this.previewOutput.release()
    }
    if (this.photoOutput) {
      this.photoOutput.release()
    }
    if (this.cameraSession) {
      this.cameraSession.release()
    }
  }

  async imageWriteAlbumExample(pixelMap?:image.PixelMap) {
    console.info('createAssetDemo');
    let context = getContext(this);
    let phAccessHelper = photoAccessHelper.getPhotoAccessHelper(context);
    let photoType: photoAccessHelper.PhotoType = photoAccessHelper.PhotoType.IMAGE;
    let extension:string = 'jpg';
    let options: photoAccessHelper.CreateOptions = {
      title: 'testPhoto'
    }
    let uri = await phAccessHelper.createAsset(photoType, extension, options);
    // 使用uri打开文件，可以持续写入内容，写入过程不受时间限制
    try {
      if(pixelMap){
        // 方式一：通过文件管理写入文件
        let file =  fs.openSync(uri, fs.OpenMode.READ_WRITE | fs.OpenMode.CREATE);
        const imageBuffer = await this.packingPixelMap2Jpg(pixelMap as image.PixelMap)
        // 写到媒体库文件中
        fs.writeSync(file.fd, imageBuffer);
        fs.closeSync(file.fd);
      }
      promptAction.showToast({message: `保存成功`})
      promptAction.showToast({
        message: '已保存至相册',
        duration: 2500
      });
    }
    catch (err) {
      console.error("error is "+ JSON.stringify(err))
      promptAction.showToast({
        message: '保存失败',
        duration: 2000
      });
    }
  }

  async  packingPixelMap2Jpg(pixelMap: PixelMap): Promise<ArrayBuffer> {
    // 创建ImagePacker实例
    const imagePackerApi = image.createImagePacker();
    // 设置打包参数
    // format：图片打包格式，只支持 jpg 和 webp
    // quality：JPEG 编码输出图片质量
    // bufferSize：图片大小，默认 10M
    const packOpts: image.PackingOption = { format: "image/jpeg", quality: 100 };
    let imageBuffer: ArrayBuffer = new ArrayBuffer(1);
    try {
      // 图片压缩或重新打包
      imageBuffer = await imagePackerApi.packing(pixelMap, packOpts);
    } catch (err) {
      console.error(`Invoke packingPixelMap2Jpg failed, err: ${JSON.stringify(err)}`);
    }
    return imageBuffer;
  }
}