如何调用HarmonyOS设备的硬件能力，如摄像头和GPS？

Question

如何调用HarmonyOS设备的硬件能力，如摄像头和GPS？

Answer 1

调用摄像头：

- 在配置文件（config.json）中申请相应的权限，如“ohos.permission.CAMERA”。
- 使用 Ability 中的方法来启动相机功能。可以使用媒体查询接口（MediaLibrary）来获取相机设备信息，然后通过相机管理接口（CameraManager）来打开相机进行拍照或录像等操作。例如：

import ohos.agp.components.Component;
import ohos.app.Context;
import ohos.hiviewdfx.HiLog;
import ohos.hiviewdfx.HiLogLabel;
import ohos.media.camera.device.CameraDevice;
import ohos.media.camera.device.CameraInfo;
import ohos.media.camera.params.Metadata;
import ohos.media.camera.params.SessionCaptureCallback;
import ohos.media.camera.params.SessionCaptureRequest;
import ohos.media.camera.params.SessionConfiguration;
import ohos.media.camera.params.SessionOutput;
import ohos.media.camera.service.CameraKit;
import ohos.media.camera.service.CameraServiceManager;
import ohos.media.image.ImageReceiver;

public class CameraExample {
    private static final HiLogLabel LABEL_LOG = new HiLogLabel(3, 0xD001100, "CameraExample");
    private CameraKit cameraKit;
    private CameraDevice cameraDevice;

    public void startCamera(Context context, Component component) {
        try {
            cameraKit = CameraServiceManager.getCameraKit();
            CameraInfo[] cameraInfos = cameraKit.getCameraIds();
            if (cameraInfos.length > 0) {
                cameraDevice = cameraKit.getCamera(cameraInfos[0]);
                SessionConfiguration sessionConfiguration = new SessionConfiguration();
                SessionOutput sessionOutput = new SessionOutput(ImageReceiver.class);
                sessionConfiguration.addOutput(sessionOutput);
                cameraDevice.createCaptureSession(sessionConfiguration, new SessionCaptureCallback() {
                    @Override
                    public void onSessionConfigured() {
                        HiLog.info(LABEL_LOG, "Session configured");
                    }

                    @Override
                    public void onCaptureStarted() {
                        HiLog.info(LABEL_LOG, "Capture started");
                    }

                    @Override
                    public void onCaptureFinished(Metadata metadata, int imageCount) {
                        HiLog.info(LABEL_LOG, "Capture finished");
                    }

                    @Override
                    public void onError(int errorCode) {
                        HiLog.error(LABEL_LOG, "Error occurred: " + errorCode);
                    }
                });
            }
        } catch (Exception e) {
            HiLog.error(LABEL_LOG, "Error starting camera: " + e.getMessage());
        }
    }
}

调用 GPS：

- 在配置文件中申请“ohos.permission.LOCATION”权限。
- 使用位置管理服务（LocationManager）来获取设备的位置信息。可以设置位置监听器（LocationCallback）来接收位置更新。例如：

import ohos.app.Context;
import ohos.hiviewdfx.HiLog;
import ohos.hiviewdfx.HiLogLabel;
import ohos.location.Location;
import ohos.location.LocationManager;

public class GpsExample {
    private static final HiLogLabel LABEL_LOG = new HiLogLabel(3, 0xD001100, "GpsExample");
    private LocationManager locationManager;

    public void startGps(Context context) {
        try {
            locationManager = LocationManager.getInstance(context);
            locationManager.addLocationCallback(new LocationCallback() {
                @Override
                public void onLocationReport(Location location) {
                    HiLog.info(LABEL_LOG, "Latitude: " + location.getLatitude() + ", Longitude: " + location.getLongitude());
                }

                @Override
                public void onStatusChanged(int statusCode) {
                    HiLog.info(LABEL_LOG, "Status changed: " + statusCode);
                }
            });
            locationManager.requestLocationUpdates(LocationRequest.DEFAULT, null);
        } catch (Exception e) {
            HiLog.error(LABEL_LOG, "Error starting GPS: " + e.getMessage());
        }
    }
}