HarmonyOS 鸿蒙Next 自定义相机实现前置摄像头拍照功能，可否提供实现代码？

1、在module.json5文件中声明如下权限：

{
  "name": "ohos.permission.CAMERA",
  "usedScene": {
    "abilities": [
      "EntryAbility"
    ],
    "when": "inuse"
  },
  "reason": "$string:reason"
},{
  "name": "ohos.permission.READ_IMAGEVIDEO",
  "usedScene": {
    "abilities": [
      "EntryAbility"
    ],
    "when": "inuse"
  },
  "reason": "$string:reason"
},{
  "name": "ohos.permission.WRITE_IMAGEVIDEO",
  "usedScene": {
    "abilities": [
      "EntryAbility"
    ],
    "when": "inuse"
  },
  "reason": "$string:reason"
}

2、Demo：

import { abilityAccessCtrl, PermissionRequestResult, Permissions } from '@kit.AbilityKit';
import { BusinessError } from '@kit.BasicServicesKit';
import { promptAction, router } from '@kit.ArkUI';
import { image } from '@kit.ImageKit';
import { photoAccessHelper } from '@kit.MediaLibraryKit';
import { fileIo } from '@kit.CoreFileKit';
import { camera } from '@kit.CameraKit';

const TAG = '[PhotoDemo]';
@Entry
@Component
struct PhotoDemo {
  context: Context = getContext(this) as Context;
  @State hasPicture: boolean = false;
  @State finalPixelMap: image.PixelMap | undefined = undefined;
  // 设置安全控件按钮属性
  @State saveButtonOptions: SaveButtonOptions = {
    icon: SaveIconStyle.FULL_FILLED,
    text: SaveDescription.SAVE_IMAGE,
    buttonType: ButtonType.Capsule
  }
  @State buffer: ArrayBuffer | undefined = undefined;
  @State surfaceId: string = '';
  @State imageSize: image.Size = { width: 1920, height: 1080 };
  private mXComponentController: XComponentController = new XComponentController;
  private cameraManager: camera.CameraManager | undefined = undefined;
  private cameraInput: camera.CameraInput | undefined = undefined;
  private photoOutput: camera.PhotoOutput | undefined = undefined;
  private previewOutput: camera.PreviewOutput | undefined = undefined;
  private cameraSession: camera.PhotoSession | undefined = undefined;
  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();
    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}`);
    })
  }
  build() {
    Column() {
      //设置返回键
      Flex({ direction: FlexDirection.Row, justifyContent: FlexAlign.Start }) {
        Text('<')
          .width(30)
          .onClick(() => {
            router.back()
          })
      }
      //预览框
      Column({ space: 20 }) {
        if (this.hasPicture) {
          Image(this.finalPixelMap)
            .objectFit(ImageFit.Fill)
            .width('100%')
            .height(300)
          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 options: photoAccessHelper.CreateOptions = {
                      title: Date.now().toString()
                    };
                    // 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);
                    // 2.1、方式一：通过文件管理写入文件
                    let file: fileIo.File = fileIo.openSync(photoUri, fileIo.OpenMode.WRITE_ONLY);
                    fileIo.writeSync(file.fd, this.buffer);
                    fileIo.closeSync(file);

                  } catch (error) {
                    let err = error as BusinessError;
                    console.error(`CameraDemo savePicture error: ${JSON.stringify(err)}`);

                  }
                }
              } else {
                console.error('CameraDemo SaveButtonOnClickResult createAsset failed.');

              }
              setTimeout(() => {
                this.hasPicture = false;
                this.finalPixelMap = undefined;
              }, 1000)
            })
        } else {
          XComponent({
            id: '',
            type: 'surface',
            libraryname: '',
            controller: this.mXComponentController
          })
            .onLoad(() => {
              // 设置Surface宽高（1920*1080），预览尺寸设置参考previewProfilesArray获取的当前设备所支持的预览分辨率大小去设置
              // 预览流与录像输出流的分辨率的宽高比要保持一致
              this.mXComponentController.setXComponentSurfaceSize({ surfaceWidth: 1920, surfaceHeight: 1080 });
              // 获取Surface ID
              this.surfaceId = this.mXComponentController.getXComponentSurfaceId();
              setTimeout(async () => {
                await this.prepareCamera();
              }, 500);
            })
            .width('100%')
            .height(300)
          Button('拍照')
            .width(200)
            .height(30)
            .onClick(async () => {
              //设置拍照参数
              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
              }
              //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;
            })
        }
      }
      .width('100%')
      .height('100%')
      .padding(15)
      .borderRadius(8)
    }
    .width('100%')
    .height('100%')
    .backgroundColor('#FFFFFF')
  }
  // 创建CameraManager对象
  createCameraManager() {
    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}`);
    });
  }
  //函数中设置监听photoAvailable，在回调中生成图片
  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;
        }
      });
    });
  }
  //相机准备
  async prepareCamera() {
    this.createCameraManager();
    if (!this.cameraManager) {
      console.error('[CameraDemo] cameraManager is undefined.');
      return;
    }
    // 获取设备支持的相机对象,根据位置可划分后置，前置，折叠态相机
    let cameraDevices: Array<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()}`)
    })
    // 获取设备支持的具体某个相机对象的支持的模式类型，包含普通拍照及普通录像两种模式,cameraDevices[0]代表后置相机
    let cameraSceneModes: Array<camera.SceneMode> = [];
    try {
      cameraSceneModes = this.cameraManager.getSupportedSceneModes(cameraDevices[1]);
      cameraSceneModes.forEach((cameraSceneMode: camera.SceneMode) => {
        console.info(`[CameraDemo] cameraSceneMode: ${cameraSceneMode.toString()}`)
      })
      //判断支持的模式类型是否包含拍照
      let isSupportPhotoMode: boolean = cameraSceneModes.indexOf(camera.SceneMode.NORMAL_PHOTO) >= 0;
      if (!isSupportPhotoMode) {
        console.error('[CameraDemo] photo mode not support');
        return;
      }
    } catch (error) {
      let err = error as BusinessError;
      console.error(`[CameraDemo] The getSupportedSceneModes call failed. error: ${JSON.stringify(err)}`)
    }
    // 创建相机输入流
    try {
      this.cameraInput = this.cameraManager.createCameraInput(cameraDevices[1]);
    } 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', cameraDevices[1], (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)}`);
    }
    // 获取相机对象支持的输出流能力，包含预览，拍照，录像等信息
    let cameraOutputCapability: camera.CameraOutputCapability = this.cameraManager.getSupportedOutputCapability(cameraDevices[1], camera.SceneMode.NORMAL_PHOTO)
    if (!cameraOutputCapability) {
      console.error('[CameraDemo] cameraManager.getSupportedOutputCapability error');
      return;
    }
    //获取当前设备支持的预览能力
    let previewProfile = cameraOutputCapability.previewProfiles[0];
    //预览流和相片分辨率的宽高比要保持一致
    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)}`);
    });
    try {
      //获取当前设备支持的拍照能力
      let photoProfile = cameraOutputCapability.photoProfiles[0];
      //拍照流和相片分辨率的宽高比要保持一致
      cameraOutputCapability.photoProfiles.forEach(profile => {
        if (profile.size.width == this.imageSize.width && profile.size.height == this.imageSize.height) {
          photoProfile = profile;
          return;
        }
      })
      //创建相机拍照输出流
      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;
    }
    //调用自定义函数，在定义的监听的回调中保存图片,该自定义函数需传参拍照输出流
    this.setPhotoOutputCb(this.photoOutput);
    //创建相机会话
    try {
      this.cameraSession = this.cameraManager.createSession(camera.SceneMode.NORMAL_PHOTO) as camera.PhotoSession;
    } 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)}`);
    });
    // 开始配置会话
    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)}`);
    }
    //调用自定义函数，配置相机的参数，传参相机会话
    this.configuringSession(this.cameraSession)
  }
  //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
  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();
    } 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(zoomRatioRange[0]);
    } catch (error) {
      let err = error as BusinessError;
      console.error(`[CameraDemo] Failed to set the zoom ratio value. error: ${JSON.stringify(err)}`);
    }
  }
}