Question

如何检测设备背面是否有摄像头？

这是我检测设备是否有手电筒的代码：

if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH) 
    || (_camera.getParameters().getSupportedFlashModes() != null)) hasFlashlight = true;
else hasFlashlight = false;

但即使设备只有没有手电筒的前置摄像头，它也是 TRUE 。

Answer 1

对于API＆gt; = 9：您可以使用Camera.getCameraInfo这样的内容：

int backCameraId = -1;
for(int i=0;i<Camera.getNumberOfCameras();i++){
    CameraInfo cameraInfo = new CameraInfo();
    Camera.getCameraInfo(i,cameraInfo);
    if(cameraInfo.facing==CameraInfo.CAMERA_FACING_BACK) {
        backCameraId = i;
        break;
    }
}
Log.d(TAG, "back camera exists ? "+(backCameraId>-1));
Log.d(TAG, "back camera id  :"+backCameraId);

对于API＆gt; = 21，建议您使用Camera2 API：

String backCameraId = null;
CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
for(String cameraId:manager.getCameraIdList()){
    CameraCharacteristics cameraCharacteristics = manager.getCameraCharacteristics(cameraId);
    Integer facing = cameraCharacteristics.get(CameraCharacteristics.LENS_FACING);
    if(facing==CameraMetadata.LENS_FACING_BACK) {
        backCameraId = cameraId;
        break;
    }
}
Log.d(TAG, "back camera exists ? "+(backCameraId!=null));
Log.d(TAG, "back camera id  :"+backCameraId);

Answer 2

尝试检查相机的数量：

import android.hardware.Camera;

int numberOfCameras = Camera.getNumberOfCameras();

如果大于1，可以肯定有后置摄像头。

Answer 3

public boolean isRearCameraAvailable(Context context) {
    return context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA);
}

检查设备是否有远离设备用户的摄像头

Answer 4

CameraManager mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);

 /** Which way the camera is facing. */
    public static enum Facing {
        FRONT, BACK;
    }

 /** Returns the ID of the first camera facing the given direction. */
    private String findCameraId(Facing facing) {
        if (facing == Facing.FRONT) {
            return findFirstFrontCameraId();
        } else {
            return findFirstBackCameraId();
        }
    }

    /** Returns the ID of the first back-facing camera. */
    private String findFirstBackCameraId() {
        Log.d(TAG, "Getting First BACK Camera");
        String cameraId = findFirstCameraIdFacing(CameraCharacteristics.LENS_FACING_BACK);
        if (cameraId == null) {
            Log.w(TAG, "No back-facing camera found.");
        }
        return cameraId;
    }

    /** Returns the ID of the first front-facing camera. */
    private String findFirstFrontCameraId() {
        Log.d(TAG, "Getting First FRONT Camera");
        String cameraId = findFirstCameraIdFacing(CameraCharacteristics.LENS_FACING_FRONT);
        if (cameraId == null) {
            Log.w(TAG, "No front-facing camera found.");
        }
        return cameraId;
    }


    /** Returns the ID of the first camera facing the given direction. */
    private String findFirstCameraIdFacing(int facing) {
        try {
            String[] cameraIds = mCameraManager.getCameraIdList();
            for (String cameraId : cameraIds) {
                CameraCharacteristics characteristics = mCameraManager
                      .getCameraCharacteristics(cameraId);
                if (characteristics.get(CameraCharacteristics.LENS_FACING) == facing) {
                    return cameraId;
                }
            }
        } catch (CameraAccessException ex) {
            Log.w(TAG, "Unable to get camera ID", ex);
        }
        return null;
    }

Android / Java：检测设备是否有BACK摄像头

4 个答案: