Question

我不知道如何在Android中获取位置（拍照时的GPS /网络）。欢迎任何建议和代码示例。我到目前为止还没有使用过位置服务，我已经尝试了很多方法，但我无法让它工作。

这是我的图像捕捉活动：

public class ImageCaptureActivity extends Activity {

// Activity request codes
private static final int CAMERA_CAPTURE_IMAGE_REQUEST_CODE = 100;
public static final int MEDIA_TYPE_IMAGE = 1;
Context context = null;

// directory name to store captured images
private static final String IMAGE_DIRECTORY_NAME = "Asisoft";

private Uri fileUri; // file url to store image

private ImageView imgPreview;
private Button btnCapturePicture;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.image_capture);

    context = getApplicationContext();
    imgPreview = (ImageView) findViewById(R.id.imgPreview);
    btnCapturePicture = (Button) findViewById(R.id.btnCapturePicture);

    /**
     * Capture image button click event
     * */
    btnCapturePicture.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // capture picture
            captureImage();
        }
    });

}

关闭相机后将调用接收活动结果方法

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // if the result is capturing Image
    if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
        if (resultCode == RESULT_OK) {
            // successfully captured the image
            // display it in image view
            previewCapturedImage();

        } else if (resultCode == RESULT_CANCELED) {
            // user cancelled Image capture
            Toast.makeText(getApplicationContext(),
                    "Cancelled", Toast.LENGTH_SHORT)
                    .show();
        } else {
            // failed to capture image
            Toast.makeText(getApplicationContext(),
                    "Error!", Toast.LENGTH_SHORT)
                    .show();
        }
    }

}

这里我们存储文件url，因为从相机应用程序返回后它将为null

@Override
protected 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);
}

这里我再次恢复fileUri

@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
    super.onRestoreInstanceState(savedInstanceState);

    // get the file url
    fileUri = savedInstanceState.getParcelable("file_uri");
}

启动相机的方法

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);

}

创建文件uri以存储图像/视频

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, "Fisierul "
                    + IMAGE_DIRECTORY_NAME + " nu a fost creat");
            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;
}

从ImageView路径显示图像

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();
    }
}


}

Answer 1

public class GPSTracker extends Service implements LocationListener {

private final Context mContext;

// Flag for GPS status
boolean isGPSEnabled = false;

// Flag for network status
boolean isNetworkEnabled = false;

// Flag for GPS status
boolean canGetLocation = false;

Location location; // Location
double latitude; // Latitude
double longitude; // Longitude

// The minimum distance to change Updates in meters
private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES = 10; // 10 meters

// The minimum time between updates in milliseconds
private static final long MIN_TIME_BW_UPDATES = 1000 * 60 * 1; // 1 minute

// Declaring a Location Manager
protected LocationManager locationManager;

public GPSTracker(Context context) {
    this.mContext = context;
    getLocation();
}

public Location getLocation() {
    try {
        locationManager = (LocationManager) mContext
                .getSystemService(LOCATION_SERVICE);

        // Getting GPS status
        isGPSEnabled = locationManager
                .isProviderEnabled(LocationManager.GPS_PROVIDER);

        // Getting network status
        isNetworkEnabled = locationManager
                .isProviderEnabled(LocationManager.NETWORK_PROVIDER);

        if (!isGPSEnabled && !isNetworkEnabled) {
            // No network provider is enabled
        } else {
            this.canGetLocation = true;
            if (isNetworkEnabled) {
                locationManager.requestLocationUpdates(
                        LocationManager.NETWORK_PROVIDER,
                        MIN_TIME_BW_UPDATES,
                        MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                Log.d("Network", "Network");
                if (locationManager != null) {
                    location = locationManager
                            .getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
                    if (location != null) {
                        latitude = location.getLatitude();
                        longitude = location.getLongitude();
                    }
                }
            }
            // If GPS enabled, get latitude/longitude using GPS Services
            if (isGPSEnabled) {
                if (location == null) {
                    locationManager.requestLocationUpdates(
                            LocationManager.GPS_PROVIDER,
                            MIN_TIME_BW_UPDATES,
                            MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
                    Log.d("GPS Enabled", "GPS Enabled");
                    if (locationManager != null) {
                        location = locationManager
                                .getLastKnownLocation(LocationManager.GPS_PROVIDER);
                        if (location != null) {
                            latitude = location.getLatitude();
                            longitude = location.getLongitude();
                        }
                    }
                }
            }
        }
    }
    catch (Exception e) {
        e.printStackTrace();
    }

    return location;
}


/**
 * Stop using GPS listener
 * Calling this function will stop using GPS in your app.
 * */
public void stopUsingGPS(){
    if(locationManager != null){
        locationManager.removeUpdates(GPSTracker.this);
    }
}


/**
 * Function to get latitude
 * */
public double getLatitude(){
    if(location != null){
        latitude = location.getLatitude();
    }

    // return latitude
    return latitude;
}


/**
 * Function to get longitude
 * */
public double getLongitude(){
    if(location != null){
        longitude = location.getLongitude();
    }

    // return longitude
    return longitude;
}

/**
 * Function to check GPS/Wi-Fi enabled
 * @return boolean
 * */
public boolean canGetLocation() {
    return this.canGetLocation;
}


/**
 * Function to show settings alert dialog.
 * On pressing the Settings button it will launch Settings Options.
 * */
public void showSettingsAlert(){
    AlertDialog.Builder alertDialog = new AlertDialog.Builder(mContext);

    // Setting Dialog Title
    alertDialog.setTitle("GPS is settings");

    // Setting Dialog Message
    alertDialog.setMessage("GPS is not enabled. Do you want to go to settings menu?");

    // On pressing the Settings button.
    alertDialog.setPositiveButton("Settings", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog,int which) {
            Intent intent = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
            mContext.startActivity(intent);
        }
    });

    // On pressing the cancel button
    alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int which) {
        dialog.cancel();
        }
    });

    // Showing Alert Message
    alertDialog.show();
}


@Override
public void onLocationChanged(Location location) {
}


@Override
public void onProviderDisabled(String provider) {
}


@Override
public void onProviderEnabled(String provider) {
}


@Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}


@Override
public IBinder onBind(Intent arg0) {
    return null;
}

}

当您在ActivityforResult()中拍照时，请使用此代码获取位置像这样

  GPSTracker gps;
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // if the result is capturing Image
        if (requestCode == CAMERA_CAPTURE_IMAGE_REQUEST_CODE) {
          gps = new GPSTracker(AndroidGPSTrackingActivity.this);

            if (resultCode == RESULT_OK) 
             {
                     previewCapturedImage();
                     if(gps.canGetLocation())
                    {
                    double latitude = gps.getLatitude();
                    double longitude = gps.getLongitude();

                    // \n is for new line
                    Toast.makeText(getApplicationContext(), "Your Location is - \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
                } else {
                    // Can't get location.
                    // GPS or network is not enabled.
                    // Ask user to enable GPS/network in settings.

                }

            } else if (resultCode == RESULT_CANCELED) {
                // user cancelled Image capture
                Toast.makeText(getApplicationContext(),
                        "Cancelled", Toast.LENGTH_SHORT)
                        .show();
            } else {
                // failed to capture image
                Toast.makeText(getApplicationContext(),
                        "Error!", Toast.LENGTH_SHORT)
                        .show();
            }
        }

    }

获取Android中拍摄照片的位置数据

1 个答案: