小白也能开发相机？Sample来教你 精华

"reqPermissions": [
  {
    "name": "ohos.permission.CAMERA"
  },
  {
    "name": "ohos.permission.WRITE_USER_STORAGE"
  },
  {
    "name": "ohos.permission.READ_USER_STORAGE"
  },
  {
    "name": "ohos.permission.MICROPHONE"
  },
  {
    "name": "ohos.permission.LOCATION"
  }
]
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private void requestPermissions() {
    String[] permissions = {
            //允许应用程序创建或删除文件，或将数据写入设备存储中的文件。
            SystemPermission.WRITE_USER_STORAGE,
            //允许应用程序从设备存储中读取文件。
            SystemPermission.READ_USER_STORAGE,
            //允许应用程序使用相机。
            SystemPermission.CAMERA,
            //允许应用程序访问麦克风。
            SystemPermission.MICROPHONE,
            //允许应用程序获取设备位置。
            SystemPermission.LOCATION
    };
    List<String> permissionFiltered = Arrays.stream(permissions)
        .filter(permission -> verifySelfPermission(permission) != IBundleManager.PERMISSION_GRANTED)
        .collect(Collectors.toList());
    requestPermissionsFromUser(permissionFiltered.toArray(new String[permissionFiltered.size()]), 0);
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private void initSurface() {
    //获取当前Ability对应的窗口，设置是否启用透明度。isEnable -指定是否启用透明度。True表示启用透明度，False表示禁用。
    getWindow().setTransparent(true);
    DirectionalLayout.LayoutConfig params = new DirectionalLayout.LayoutConfig(
        ComponentContainer.LayoutConfig.MATCH_PARENT, ComponentContainer.LayoutConfig.MATCH_PARENT);
    surfaceProvider = new SurfaceProvider(this);
    surfaceProvider.setLayoutConfig(params);
    /**
     * 设置是否将此SurfaceProvider的Surface放置在AGP容器组件的顶层。
     * 参数说明：
     * toTop -指定是否将相机界面固定在顶部。值true表示将Surface放在AGP容器组件的顶层，而值false表示相反。*/
    surfaceProvider.pinToZTop(false);
    //通过addCallback()添加界面操作的回调
    surfaceProvider.getSurfaceOps().get().addCallback(new SurfaceCallBack());
    surfaceContainer.addComponent(surfaceProvider);
}
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private class SurfaceCallBack implements SurfaceOps.Callback {
    @Override
    public void surfaceCreated(SurfaceOps callbackSurfaceOps) {
        if (callbackSurfaceOps != null) {
            //setFixedSize:设置界面的固定大小。参数说明：宽度-指示界面的宽度。高度-指示界面的高度。
            callbackSurfaceOps.setFixedSize(SCREEN_HEIGHT,SCREEN_WIDTH);
        }
//设置延时200ms的postTask，用于相机界面的显示
        eventHandler.postTask(new Runnable() {
            @Override
            public void run() {
                openCamera();
            }
        },200);
    }
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private void openCamera() {
    //ImageReceiver:连接到图像输出设备的图像接收器，并提供一个缓冲队列来接收图像数据
    //create:根据指定的图像宽度、高度、格式和缓冲队列容量创建ImageReceiver实例
    imageReceiver = ImageReceiver.create(SCREEN_WIDTH, SCREEN_HEIGHT, ImageFormat.JPEG, IMAGE_RCV_CAPACITY);
    //设置接收到新图像数据时将调用的图像侦听器。
    imageReceiver.setImageArrivalListener(this::saveImage);
    //获取CameraKit实例
    CameraKit cameraKit = CameraKit.getInstance(getApplicationContext());
    //获取当前使用的设备支持的逻辑相机列表
    String[] cameraList = cameraKit.getCameraIds();
    String cameraId = "";
    //获取当前逻辑相机的信息
    for (String logicalCameraId : cameraList) {
        int faceType = cameraKit.getCameraInfo(logicalCameraId).getFacingType();
        switch (faceType){
            case CameraInfo.FacingType.CAMERA_FACING_FRONT:
                if (isFrontCamera) {
                    cameraId = logicalCameraId;
                }
                break;
            case CameraInfo.FacingType.CAMERA_FACING_BACK:
                if (!isFrontCamera) {
                    cameraId = logicalCameraId;
                }
                break;
            case CameraInfo.FacingType.CAMERA_FACING_OTHERS:
            default:
                break;
        }
    }
    if (cameraId != null && !cameraId.isEmpty()) {
        CameraStateCallbackImpl cameraStateCallback = new CameraStateCallbackImpl();
        /**createCamera()用于创建相机对象
         * 该方法的第一个参数代表要打开的摄像头ID；
         * 第二个参数用于监听摄像头的状态；
         * 第三个参数代表执行callback的Handler，如果程序希望直接在当前线程中执行callback，则可将handler参数设为null。*/
        cameraKit.createCamera(cameraId, cameraStateCallback, eventHandler);
    }
}
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@Override
public void onCreated(Camera camera) {
    previewSurface = surfaceProvider.getSurfaceOps().get().getSurface();
    if (previewSurface == null) {
        HiLog.error(LABEL_LOG, "%{public}s", "Create camera filed, preview surface is null");
        return;
    }
    //获取相机Config.Builder实例。
    CameraConfig.Builder cameraConfigBuilder = camera.getCameraConfigBuilder();
    //addSurface:添加界面作为相机流的输出。
    cameraConfigBuilder.addSurface(previewSurface);
    cameraConfigBuilder.addSurface(imageReceiver.getRecevingSurface());
    camera.configure(cameraConfigBuilder.build());
    cameraDevice = camera;
    updateComponentVisible(true);
}
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@Override
public void onConfigured(Camera camera) {
    FrameConfig.Builder framePreviewConfigBuilder = camera.getFrameConfigBuilder(FRAME_CONFIG_PREVIEW);
    framePreviewConfigBuilder.addSurface(previewSurface);
    //triggerLoopingCapture:开始循环帧捕获。循环帧捕获通常用于预览或录制
    camera.triggerLoopingCapture(framePreviewConfigBuilder.build());
}
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private void initComponents() {
    Component takePhoto = findComponentById(ResourceTable.Id_take_photo);
    Component videoRecord = findComponentById(ResourceTable.Id_video_record);
    //设置点击事件侦听器，用于拍摄照片
    takePhoto.setClickedListener((component) -> startAbility(TakePhotoAbility.class.getName()));
    //设置点击事件侦听器，用于录制视频
    videoRecord.setClickedListener((component) -> startAbility(VideoRecordAbility.class.getName()));
}
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Image takePhotoImage = (Image) findComponentById(ResourceTable.Id_tack_picture_btn);
//setClickedListener:为组件中的单击事件注册侦听器。
takePhotoImage.setClickedListener(this::takeSingleCapture);

private void takeSingleCapture(Component component) {
    if (cameraDevice == null || imageReceiver == null) {
        return;
    }
    //用于配置帧捕获、图像处理和图像输出的接口
    FrameConfig.Builder framePictureConfigBuilder = cameraDevice.getFrameConfigBuilder(FRAME_CONFIG_PICTURE);
    framePictureConfigBuilder.addSurface(imageReceiver.getRecevingSurface());
    FrameConfig pictureFrameConfig = framePictureConfigBuilder.build();
    //triggerSingleCapture():开始单帧捕获。这种方法通常用于拍照。
    cameraDevice.triggerSingleCapture(pictureFrameConfig);
}
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Image takePhotoImage = (Image) findComponentById(ResourceTable.Id_tack_picture_btn);
//setClickedListener:为组件中的单击事件注册侦听器。
takePhotoImage.setClickedListener(this::takeSingleCapture);

private void takeSingleCapture(Component component) {
    if (cameraDevice == null || imageReceiver == null) {
        return;
    }
    //用于配置帧捕获、图像处理和图像输出的接口
    FrameConfig.Builder framePictureConfigBuilder = cameraDevice.getFrameConfigBuilder(FRAME_CONFIG_PICTURE);
    framePictureConfigBuilder.addSurface(imageReceiver.getRecevingSurface());
    FrameConfig pictureFrameConfig = framePictureConfigBuilder.build();
    //triggerSingleCapture():开始单帧捕获。这种方法通常用于拍照。
    cameraDevice.triggerSingleCapture(pictureFrameConfig);
}
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private void takeMultiCapture(Component component) {
    FrameConfig.Builder framePictureConfigBuilder = cameraDevice.getFrameConfigBuilder(FRAME_CONFIG_PICTURE);
    framePictureConfigBuilder.addSurface(imageReceiver.getRecevingSurface());
    List<FrameConfig> frameConfigs = new ArrayList<>();
    FrameConfig firstFrameConfig = framePictureConfigBuilder.build();
    frameConfigs.add(firstFrameConfig);
    FrameConfig secondFrameConfig = framePictureConfigBuilder.build();
    frameConfigs.add(secondFrameConfig);
    /**triggerMultiCapture(frameConfigs):启动多帧捕获。
    cameraDevice.triggerMultiCapture(frameConfigs);
}
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/**
  * 存储照片*/
private void saveImage(ImageReceiver receiver) {
    //getFilesDir():获取应用程序在设备内部存储上的文件存储目录。
    File saveFile = new File(getFilesDir(), "IMG_" + System.currentTimeMillis() + ".jpg");
    ohos.media.image.Image image = receiver.readNextImage();
    //定义图像格式，提供获取图像格式信息的接口。
    ohos.media.image.Image.Component component = image.getComponent(ImageFormat.ComponentType.JPEG);
    byte[] bytes = new byte[component.remaining()];
    component.read(bytes);
    try (FileOutputStream output = new FileOutputStream(saveFile)) {
        output.write(bytes);
        output.flush();
        showTips(this, "Take photo succeed");
    } catch (IOException e) {
        HiLog.error(LABEL_LOG, "%{public}s", "saveImage IOException");
    }
}
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private void initMediaRecorder() {
    mediaRecorder = new Recorder();
    VideoProperty.Builder videoPropertyBuilder = new VideoProperty.Builder();
    videoPropertyBuilder.setRecorderBitRate(10000000);//setRecorderBitRate:设置视频编码码率。
    videoPropertyBuilder.setRecorderDegrees(90);  //setRecorderDegrees:设置视频旋转角度。
    videoPropertyBuilder.setRecorderFps(30);//setRecorderFps:设置视频帧捕获速率。
    videoPropertyBuilder.setRecorderHeight(Math.min(1440, 720));//设置视频高度。
    videoPropertyBuilder.setRecorderWidth(Math.max(1440, 720));//设置视频宽度。
    videoPropertyBuilder.setRecorderVideoEncoder(Recorder.VideoEncoder.H264);//setRecorderVideoEncoder:设置视频编码格式。
    videoPropertyBuilder.setRecorderRate(30);//setRecorderRate:设置视频帧率。

    Source source = new Source();
    //表示使用麦克风作为音频源。
    source.setRecorderAudioSource(Recorder.AudioSource.MIC);
    //表示使用相机界面作为视频源。
    source.setRecorderVideoSource(Recorder.VideoSource.SURFACE);
    mediaRecorder.setSource(source);
    //setOutputFormat:设置输出文件格式。
    mediaRecorder.setOutputFormat(Recorder.OutputFormat.MPEG_4);
    //getFilesDir():获取文件存储目录。
    File file = new File(getFilesDir(), "VID_" + System.currentTimeMillis() + ".mp4");
    StorageProperty.Builder storagePropertyBuilder = new StorageProperty.Builder();
    storagePropertyBuilder.setRecorderFile(file);
    mediaRecorder.setStorageProperty(storagePropertyBuilder.build());

    AudioProperty.Builder audioPropertyBuilder = new AudioProperty.Builder();
    //setRecorderAudioEncoder:设置音频编码格式。
    audioPropertyBuilder.setRecorderAudioEncoder(Recorder.AudioEncoder.AAC);
    mediaRecorder.setAudioProperty(audioPropertyBuilder.build());
    mediaRecorder.setVideoProperty(videoPropertyBuilder.build());
    mediaRecorder.prepare();
}
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//为组件中的长单击事件注册侦听器（单击并按住组件）。所有注册的观察员都将收到调度到组件的长单击事件的通知。
videoRecord.setLongClickedListener(component -> {
    startRecord();
    isRecording = true;
    videoRecord.setPixelMap(ResourceTable.Media_ic_camera_video_press);
});

private void startRecord() {
    if (cameraDevice == null) {
        HiLog.error(LABEL_LOG, "%{public}s", "startRecord failed, parameters is illegal");
        return;
    }
    synchronized (lock) {
        initMediaRecorder();
        recorderSurface = mediaRecorder.getVideoSurface();
        cameraConfigBuilder = cameraDevice.getCameraConfigBuilder();
        try {
            cameraConfigBuilder.addSurface(previewSurface);
            if (recorderSurface != null) {
                //添加界面作为相机流的输出。
                cameraConfigBuilder.addSurface(recorderSurface);
            }
            cameraDevice.configure(cameraConfigBuilder.build());
        } catch (IllegalStateException | IllegalArgumentException e) {
            HiLog.error(LABEL_LOG, "%{public}s", "startRecord IllegalStateException ");
        }
    }
    new ToastDialog(this).setText("Recording").show();
}
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//在组件中注册触摸事件的侦听器。所有注册的观察员都将收到调度到组件的触摸事件的通知。
videoRecord.setTouchEventListener((component, touchEvent) -> {
    if (touchEvent != null && touchEvent.getAction() == TouchEvent.PRIMARY_POINT_UP && isRecording) {
        stopRecord();
        isRecording = false;
        videoRecord.setPixelMap(ResourceTable.Media_ic_camera_video_ready);
    }
    return true;
});

private void stopRecord() {
    synchronized (lock) {
        try {
            eventHandler.postTask(() -> mediaRecorder.stop());//stop():停止录制。
            if (cameraDevice == null || cameraDevice.getCameraConfigBuilder() == null) {
                HiLog.error(LABEL_LOG, "%{public}s", "StopRecord cameraDevice or getCameraConfigBuilder is null");
                return;
            }
            cameraConfigBuilder = cameraDevice.getCameraConfigBuilder();
            cameraConfigBuilder.addSurface(previewSurface);
            cameraConfigBuilder.removeSurface(recorderSurface);
            cameraDevice.configure(cameraConfigBuilder.build());
        } catch (IllegalStateException | IllegalArgumentException exception) {
            HiLog.error(LABEL_LOG, "%{public}s", "stopRecord occur exception");
        }
    }
    new ToastDialog(this).setText("video saved").show();
}
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private void releaseCamera() {
    if (cameraDevice != null) {
        //release():释放摄像机。
        //释放摄像机后，摄像机的所有操作都不可用。任何操作都会导致意外结果或异常。
        cameraDevice.release();
    }
    if (imageReceiver != null) {
        imageReceiver.release();
    }
}
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