java - Android 无法在表面 View 中切换到前置摄像头

Question

我尝试在表面 View 中打开前置摄像头，但得到的结果是无法连接到摄像头服务

尝试过的代码

    mCamera= Camera.open(cameraId);

CAMERA_FACING_BACK 为 0

CAMERA_FACING_FRONT 为 1

解决方案是什么？

Answer 1

是的，我得到了答案

    reverseCamera.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            boolean hasFront = hasFrontCamera();
            if (hasFront) {
                reverseCamera.setVisibility(View.VISIBLE);
                mCamera.stopPreview();
                mCamera.release();

                if (currentCameraId == Camera.CameraInfo.CAMERA_FACING_BACK) {
                    currentCameraId = Camera.CameraInfo.CAMERA_FACING_FRONT;
                } else {
                    currentCameraId = Camera.CameraInfo.CAMERA_FACING_BACK;
                }
                mCamera = Camera.open(currentCameraId);

                setCameraDisplayOrientation(MainActivity.this, currentCameraId, mCamera);
                try {

                    mCamera.setPreviewDisplay(mHolder);
                } catch (IOException e) {
                    e.printStackTrace();
                }
                mCamera.startPreview();
            } else {
                reverseCamera.setVisibility(View.GONE);
            }
        }

    });

    public static void setCameraDisplayOrientation(Activity activity,
                                               int cameraId, android.hardware.Camera camera) {
    android.hardware.Camera.CameraInfo info =
            new android.hardware.Camera.CameraInfo();
    android.hardware.Camera.getCameraInfo(cameraId, info);
    int rotation = activity.getWindowManager().getDefaultDisplay()
            .getRotation();
    int degrees = 0;
    switch (rotation) {
        case Surface.ROTATION_0:
            degrees = 0;
            break;
        case Surface.ROTATION_90:
            degrees = 90;
            break;
        case Surface.ROTATION_180:
            degrees = 180;
            break;
        case Surface.ROTATION_270:
            degrees = 270;
            break;
    }

    int result;
    if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
        result = (info.orientation + degrees) % 360;
        result = (360 - result) % 360;  // compensate the mirror
    } else {  // back-facing
        result = (info.orientation - degrees + 360) % 360;
    }
    camera.setDisplayOrientation(result);
}