我试图获取拍摄照片的地方的GPS坐标。但有时，纬度和经度具有默认的0.0d值，应用程序崩溃，即使GPS已激活。为什么我总能获得坐标？
public class FragmentTab2_Image extends Fragment {
GPSTracker gps;
// Fragment request codes
private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
public static final int MEDIA_TYPE_IMAGE = 1;
// directory name to store captured images
private static final String IMAGE_DIRECTORY_NAME = "blabla";
private Uri fileUri; // file url to store image
private ImageView imgPreview;
private Button btnCapturePicture;
Context thiscontext;
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
@Override
public void onViewStateRestored(Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
if (savedInstanceState != null)
savedInstanceState.getParcelable("file_uri");
}
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState){
View view = inflater.inflate(R.layout.image_capture, container, false);
thiscontext = container.getContext();
imgPreview = (ImageView) view.findViewById(R.id.imgPreview);
btnCapturePicture = (Button) view.findViewById(R.id.btnCapturePicture);
/**
* Capture image button click event
* */
btnCapturePicture.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// capture picture
captureImage();
}
});
return view;
}
//
/**
* Receiving activity result method will be called after closing the camera
* + get gps location of picture
* */
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
// if the result is capturing Image
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
//TODO
gps = new GPSTracker(thiscontext);
if (resultCode == Activity.RESULT_OK) {
// successfully captured the image
// display it in image view
previewCapturedImage();
//get gps location coordinates
if(gps.canGetLocation())
{
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
Toast.makeText(thiscontext, "Your Location is - \nLat: " + latitude + "\nLong: "
+ longitude, Toast.LENGTH_LONG).show();
//from latitude and longitude to address
Geocoder gcd = new Geocoder(thiscontext, Locale.getDefault());
List<Address> addresses = null;
try {
addresses = gcd.getFromLocation(latitude, longitude, 1);
} catch (IOException e) {
e.printStackTrace();
}
if(latitude != 0.0d && longitude != 0.0d)
if (addresses.size() > 0) {
String tara = addresses.get(0).getCountryName();
String judet = addresses.get(0).getLocality();
String oras = addresses.get(0).getSubLocality();
String adresa = addresses.get(0).getAddressLine(0);
System.out.println(tara + ", " + judet + ", " + oras + ", " + adresa + "\n");
}
if (latitude == 0.0d || longitude == 0.0d)
Toast.makeText(thiscontext, "Coordinates weren't taken",
Toast.LENGTH_LONG).show();
} else {
// Can't get location.
// GPS or network is not enabled.
// Ask user to enable GPS/network in settings.
Toast.makeText(thiscontext, "Activate GPS", Toast.LENGTH_LONG).show();
}
//TODO
//GET DATE OF IMAGE
String pathToFile = fileUri.getPath();
File file = new File(pathToFile);
if(file.exists()) {
String date = new SimpleDateFormat("dd-MM-yyyy HH-mm-ss").format(
new Date(file.lastModified())
);
Toast.makeText(thiscontext, date, Toast.LENGTH_LONG)
.show();
}
} else if (resultCode == Activity.RESULT_CANCELED) {
// user cancelled Image capture
Toast.makeText(thiscontext,
"Canceled", Toast.LENGTH_SHORT)
.show();
} else {
// failed to capture image
Toast.makeText(thiscontext,
"Error!", Toast.LENGTH_SHORT)
.show();
}
}
}
/**
* Here we store the file url as it will be null after returning from camera
* app
*/
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
// save file url in bundle as it will be null on scren orientation
// changes
outState.putParcelable("file_uri", fileUri);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if (savedInstanceState != null) {
// Restore last state for checked position.
fileUri = savedInstanceState.getParcelable("file_uri");
}
}
/*
________________________________________________________________________________________
helper methods :
*/
//method to fire camera
private void captureImage() {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = getOutputMediaFileUri(MEDIA_TYPE_IMAGE);
intent.putExtra(MediaStore.EXTRA_OUTPUT, fileUri);
// start the image capture Intent
startActivityForResult(intent, CAMERA_CAPTURE_IMAGE_REQUEST_CODE);
}
/**
* Creating file uri to store image/video
*/
public Uri getOutputMediaFileUri(int type) {
return Uri.fromFile(getOutputMediaFile(type));
}
/*
* returning image / video
*/
private static File getOutputMediaFile(int type) {
// External sdcard location
File mediaStorageDir = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
IMAGE_DIRECTORY_NAME);
// Create the storage directory if it does not exist
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d(IMAGE_DIRECTORY_NAME, "File"
+ IMAGE_DIRECTORY_NAME + " was not created");
return null;
}
}
// Create a media file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss",
Locale.getDefault()).format(new Date());
File mediaFileName;
if (type == MEDIA_TYPE_IMAGE) {
mediaFileName = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + timeStamp + ".jpg");
} else {
return null;
}
return mediaFileName;
}
/*
* Display image from a path to ImageView
*/
private void previewCapturedImage() {
try {
imgPreview.setVisibility(View.VISIBLE);
// bimatp factory
BitmapFactory.Options options = new BitmapFactory.Options();
// downsizing image as it throws OutOfMemory Exception for larger
// images
options.inSampleSize = 8;
final Bitmap bitmap = BitmapFactory.decodeFile(fileUri.getPath(),
options);
imgPreview.setImageBitmap(bitmap);
} catch (NullPointerException e) {
e.printStackTrace();
}
}
}
片段是MainActivity的一部分。
logcat的：
java.lang.RuntimeException: Failure delivering result ResultInfo{who=android:fragment:1, request=100, result=-1, data=null} to activity {package/package.MainActivity}: java.lang.NullPointerException
at android.app.ActivityThread.deliverResults(ActivityThread.java:3551)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3594)
at android.app.ActivityThread.access$1400(ActivityThread.java:161)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1313)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:157)
at android.app.ActivityThread.main(ActivityThread.java:5356)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at ro.asisoft.ImaginiAsigurari.app1.fragments.FragmentTab2_Image.onActivityResult(FragmentTab2_Image.java:130)
at android.app.Activity.dispatchActivityResult(Activity.java:5622)
at android.app.ActivityThread.deliverResults(ActivityThread.java:3547)
at android.app.ActivityThread.handleSendResult(ActivityThread.java:3594)
at android.app.ActivityThread.access$1400(ActivityThread.java:161)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1313)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:157)
at android.app.ActivityThread.main(ActivityThread.java:5356)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1265)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1081)
at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：3)
尝试将GPSTracker对象初始化为onCreateView()或onCreate()
gps = new GPSTracker(getActivity());