我有一个竖屏摄像头应用程序，可以从前置和后置摄像头拍照。我将图像保存到SD卡中，并尝试找到相应的exif值，但始终得到0。但是，我能够获取设备中存储的其他图像（如下载的图片）的预期exif方向值。
我该如何解决这个问题？有人可以帮帮我吗？
以下是用于保存图片并查找方向的代码：
PictureCallback myPictureCallback_JPG = new PictureCallback() {
@Override
public void onPictureTaken(byte[] arg0, Camera arg1) {
// TODO Auto-generated method stub
try {
File APP_FILE_PATH = new File(Environment.getExternalStorageDirectory()
.getPath() + "/Myapp/");
if (!APP_FILE_PATH.exists()) {
APP_FILE_PATH.mkdirs();
}
File file = new File(APP_FILE_PATH, "image.jpg");
FileOutputStream fos = new FileOutputStream(file);
fos.write(arg0);
fos.close();
imageFileUri=Uri.fromfile(file); getApplicationContext().getContentResolver().notifyChange(
imageFileUri, null);
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,
Uri.parse("file://"
+ Environment.getExternalStorageDirectory())));
ExifInterface exif = new ExifInterface(file.getAbsolutePath());
int orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
} catch (Exception e) {
}
}
};
以下是创建和更改表面代码的函数
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, width, height);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
camera.setParameters(parameters);
camera.startPreview();
startPreview();
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
Camera.CameraInfo info=new Camera.CameraInfo();
for (int i=0; i < Camera.getNumberOfCameras(); i++) {
Camera.getCameraInfo(i, info);
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
camera=Camera.open(i);
defaultCameraId = i;
}
}
}
if (camera == null) {
camera=Camera.open();
}
try {
camera.setPreviewDisplay(surfaceHolder);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Camera.Parameters parameters = camera.getParameters();
android.hardware.Camera.CameraInfo info =
new android.hardware.Camera.CameraInfo();
android.hardware.Camera.getCameraInfo(defaultCameraId, info);
int rotation = this.getWindowManager().getDefaultDisplay()
.getRotation();
if (Integer.parseInt(Build.VERSION.SDK) >= 8)
{
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;
} else { // back-facing
result = (info.orientation - degrees + 360) % 360;
}
camera.setDisplayOrientation(result);
}
else
{
parameters.set("orientation", "portrait");
}
camera.setParameters(parameters);
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SecurityException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.1;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
for (Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}