HarmonyOS 鸿蒙Next Camera Kit——关于手动切换镜头

发布于 1周前 作者 nodeper 来自 鸿蒙OS

HarmonyOS 鸿蒙Next Camera Kit——关于手动切换镜头

描述:进入相机页面默认设置为后置摄像头,并且可以显示预览流和实现拍照
当我需要点击按钮进行前置与后置镜头切换时,出现黑屏。请问是哪个环节出现了问题,或者是否存在哪个API支持动态切换镜头
步骤:
1.暂停当前会话
2.移除当前会话的输入输出流(例:具有后置的
3.新增输入输出流 (例:具有前置的
4.配置会话
代码如下:
/*
* 切换摄像头
* */
async changeLens(isFrontLens: boolean, XComponentSurfaceId: string, sceneModel: camera.SceneMode){
if (this.photoSession === undefined) {
LoggerJoy.info(CameraPage--> error message : captureSession is undefined)
return
}

//暂停会话
await this.photoSession.stop()

//销毁之前的输入输出流
await this.cameraInput?.close()
await this.previewOutput?.release()
this.cameraInput = undefined
this.previewOutput = undefined

//开始配置会话
this.photoSession.beginConfig()

//移除会话中的输入输出流
this.photoSession.removeInput(this.cameraInput)
this.photoSession.removeOutput(this.previewOutput)

//新增
await this.createCameraInput(isFrontLens) //创建输入流
this.createPreviewOutput(isFrontLens, XComponentSurfaceId, sceneModel) //创建预览输出流输出流

//切换
this.photoSession.addInput(this.cameraInput) //向会话中添加相机输入流
this.photoSession.addOutput(this.previewOutput) //向会话中添加预览输出流
await this.photoSession.commitConfig() //提交会话配置
await this.photoSession.start() //启动会话
}

通过下列方法区分是前置还是后置,然后选择对应设备,如有错误还请纠正
//supportCameras[0]是后置,supportCameras[1]是前置
let supportCameras: Array<camera.CameraDevice> = this.cameraManager.getSupportedCameras()
let cameraDevice = isFrontCamera ? this.supportCameras[1]: this.supportCameras[0]

2 回复
import { camera } from '[@kit](/user/kit).CameraKit';
import { BusinessError } from '[@kit](/user/kit).BasicServicesKit';
import { image } from '[@kit](/user/kit).ImageKit';
import { photoAccessHelper } from '[@kit](/user/kit).MediaLibraryKit';
import { abilityAccessCtrl, PermissionRequestResult, Permissions } from '[@kit](/user/kit).AbilityKit';
import { promptAction, router } from '[@kit](/user/kit).ArkUI';
import { fileIo } from '[@kit](/user/kit).CoreFileKit';

const TAG = '[CameraDemo]';

[@Entry](/user/Entry)
[@Component](/user/Component)
struct CameraDemo {
context: Context = getContext(this) as Context;
[@State](/user/State) pixelMap: image.PixelMap | undefined = undefined;
[@State](/user/State) finalPixelMap: image.PixelMap | undefined = undefined;
[@State](/user/State) buffer: ArrayBuffer | undefined = undefined;
[@State](/user/State) surfaceId: string = '';
[@State](/user/State) hasPicture: boolean = false;
[@State](/user/State) fileNames: string[] = [];
[@State](/user/State) imageSize: image.Size = { width: 1920, height: 1080 };
[@State](/user/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 imageReceiver: image.ImageReceiver | undefined = undefined;
[@State](/user/State) ca: 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}`);
})
}

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() {
Column() {
Column({ space: 20 }) {
if (this.hasPicture) {
Image(this.finalPixelMap)
.objectFit(ImageFit.Fill)
.width('100%')
.height(600)

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);
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 {
XComponent({
id: '',
type: 'surface',
libraryname: '',
controller: this.mXComponentController
})
.onLoad(() => {
// 设置Surface宽高(1920*1080),预览尺寸设置参考前面 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(this.ca);
}, 500);
})
.width('100%')
.height(600)

Button('拍照')
.width(60)
.height(60)
.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
}
// 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;
})
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('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%')
.height('100%')
.padding(15)
.borderRadius(8)
}
.width('100%')
.height('100%')
.backgroundColor('#FFFFFF')
}

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(cameraDevices[0]);
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);

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();
} 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)}`);
}
}

// 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.NV21, // 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(90.0);
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;
}
});
});
}

printCameraOutputCapability(cameraOutputCapability: camera.CameraOutputCapability) {
let previewProfileArr: Array<camera.Profile> = cameraOutputCapability.previewProfiles;
let photoProfileArr: Array<camera.Profile> = cameraOutputCapability.photoProfiles;
let videoProfileArr: Array<camera.VideoProfile> = cameraOutputCapability.videoProfiles;
let supportedMetadataObjectTypeArr: Array<camera.MetadataObjectType> =
cameraOutputCapability.supportedMetadataObjectTypes;
previewProfileArr.forEach((value: camera.Profile, index: number) => {
console.info(`CameraDemo 支持的预览尺寸: [${value.size.width},${value.size.height}]`);
})
photoProfileArr.forEach((value: camera.Profile, index: number) => {
console.info(`CameraDemo 支持的拍照尺寸: [${value.size.width},${value.size.height}]`);
})
videoProfileArr.forEach((value: camera.VideoProfile, index: number) => {
console.info(`CameraDemo 支持的录像尺寸: [${value.size.width},${value.size.height}], 支持的帧率范围: [${value.frameRateRange.min},${value.frameRateRange.max}]`);
})
supportedMetadataObjectTypeArr.forEach((value: camera.MetadataObjectType, index: number) => {
console.info(`CameraDemo 支持的metadata流类型: ${value}`);
})
}

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()
}
}
}

关于HarmonyOS 鸿蒙Next Camera Kit手动切换镜头的操作,以下是一些专业的解决步骤:

  1. 权限设置

    • 确保应用已获取相机及媒体权限,包括“ohos.permission.CAMERA”、“ohos.permission.WRITE_MEDIA”等。
  2. 创建相机输入对象

    • 使用CameraManager创建cameraInput对象,通过选择摄像头设备索引来切换前后置摄像头。通常,索引0代表后置摄像头,索引1代表前置摄像头。
  3. 释放与重建资源

    • 在切换摄像头前,释放之前的相机流对象,如photoSession、previewOutput等。
    • 切换后,重新创建并配置这些资源。
  4. 检查硬件与软件

    • 确保前置摄像头无物理遮挡或损坏。
    • 检查系统是否有更新,确保使用的是最新版本的HarmonyOS。
  5. 编程实现

    • 在代码中,通过监听按钮点击事件来触发摄像头切换逻辑。

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