Develop Reference

How to update weather with onCreate()?

I've been working on a weather app, and I know it's not perfect (I'm just starting out with android development), but I'm not sure how to update the weather info on every startup. I tried to keep everything in the onCreate() method, but it just "sticks" on the location and conditions that I used when I first started.
I have been able to work around this with a button that gets the new location and weather conditions when it is pressed, but that's not very intuitive. I'm wondering how I can get new conditions on app startup. Might it involve calling onRestart()?
Here's my only activity in the app:
package com.photonfighterlabs.dropweather;
import android.Manifest;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.graphics.drawable.Drawable;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import com.ftoslab.openweatherretrieverz.CurrentWeatherInfo;
import com.ftoslab.openweatherretrieverz.OpenWeatherRetrieverZ;
import com.ftoslab.openweatherretrieverz.WeatherCallback;
import com.ftoslab.openweatherretrieverz.WeatherUnitConverter;
import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.tasks.OnSuccessListener;
import java.io.IOException;
import java.util.List;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class WeatherActivity extends Activity {
private double lat;
private double lng;
private String temp;
private String icon;
private TextView tempTextView;
private TextView cityTextView;
private TextView conditionsTextView;
private int LOCATION_PERMISSION_ID = 1001;
CurrentWeatherInfo currentWeatherInfoF;
private String city;
private List<Address> addresses;
private FusedLocationProviderClient mFusedLocationClient;
OpenWeatherRetrieverZ retriever;
ImageView image;
Geocoder geocoder;
#Override
public void onCreate(Bundle bundle) {
super.onCreate(bundle);
setContentView(R.layout.activity_weather);
retriever = new OpenWeatherRetrieverZ(API_KEY); // hidden for obvious reasons, but working
mFusedLocationClient = LocationServices.getFusedLocationProviderClient(this);
geocoder = new Geocoder(this, Locale.getDefault());
tempTextView = (TextView) findViewById(R.id.temp_text_view);
cityTextView = (TextView) findViewById(R.id.city_text_view);
conditionsTextView = (TextView) findViewById(R.id.conditions_text_view);
image = (ImageView) findViewById(R.id.conditions_image);
if (ContextCompat.checkSelfPermission(WeatherActivity.this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(WeatherActivity.this, new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_PERMISSION_ID);
return;
}
mFusedLocationClient.getLastLocation()
.addOnSuccessListener(this, new OnSuccessListener<Location>() {
#Override
public void onSuccess(Location location) {
if (location != null)
lat = location.getLatitude();
lng = location.getLongitude();
try {
addresses = geocoder.getFromLocation(lat, lng, 1);
} catch (IOException e) {
e.printStackTrace();
}
if (!addresses.isEmpty()) {
city = addresses.get(0).getLocality();
cityTextView.setText("Current Weather - " + city);
Log.d("City", city);
}
Log.d("LAT", String.valueOf(lat));
Log.d("LNG", String.valueOf(lng));
}
});
retriever.updateCurrentWeatherInfo(lat, lng, new WeatherCallback() {
#Override
public void onReceiveWeatherInfo(CurrentWeatherInfo currentWeatherInfo) {
currentWeatherInfoF = WeatherUnitConverter.convertToImperial(currentWeatherInfo);
}
#Override
public void onFailure(String error) {
Toast.makeText(WeatherActivity.this, error, Toast.LENGTH_SHORT).show();
}
});
}
public void onRetrieveButtonClick(View view) {
mFusedLocationClient.getLastLocation()
.addOnSuccessListener(this, new OnSuccessListener<Location>() {
#Override
public void onSuccess(Location location) {
if (location != null)
lat = location.getLatitude();
lng = location.getLongitude();
try {
addresses = geocoder.getFromLocation(lat, lng, 1);
} catch (IOException e) {
e.printStackTrace();
}
if (!addresses.isEmpty()) {
city = addresses.get(0).getLocality();
cityTextView.setText("Current Weather - " + city);
Log.d("City", city);
}
Log.d("LAT", String.valueOf(lat));
Log.d("LNG", String.valueOf(lng));
}
});
retriever.updateCurrentWeatherInfo(lat, lng, new WeatherCallback() {
#Override
public void onReceiveWeatherInfo(CurrentWeatherInfo currentWeatherInfo) {
currentWeatherInfoF = WeatherUnitConverter.convertToImperial(currentWeatherInfo);
}
#Override
public void onFailure(String error) {
Toast.makeText(WeatherActivity.this, error, Toast.LENGTH_SHORT).show();
}
});
temp = currentWeatherInfoF.getCurrentTemperature();
Log.d("TMP : ", String.valueOf(temp));
tempTextView.setText( String.valueOf((int) Double.parseDouble(temp)) + (char) 0x00B0);
conditionsTextView.setText(currentWeatherInfoF.getWeatherDescriptionLong());
String iconURL = currentWeatherInfoF.getWeatherIconLink().toString();
Pattern p = Pattern.compile("\\d\\w(n|d)");
Matcher m = p.matcher(iconURL);
if (m.find()) {
icon = m.group();
Log.d("ICON", icon);
String iconName = "r" + icon;
image.setImageResource(getResources().getIdentifier(iconName, "drawable", getPackageName()));
Log.d("NAME", iconName);
}
}
}

getLastLocation() and updateCurrentWeatherInfo(...) are both asynchronous operations. You start them both at the same time which means that updateCurrentWeatherInfo will most likely run before the position is available.
You must start it only after you have got the position, for example from the onSuccess listener.

You have tried with onResume() method?
You can use it and when the view is visible wi

Awareness offers a snapshot-API for obtaining the weather via getWeather() API method at the device location without managing location access or integrating with APIs that query weather from server on-demand.
Illustrative code-snippet:
Awareness.SnapshotApi.getWeather(mGoogleApiClient)
.setResultCallback(new ResultCallback<WeatherResult>() {
#Override
public void onResult(#NonNull WeatherResult weatherResult) {
if (!weatherResult.getStatus().isSuccess()) {
Log.e(TAG, "Could not get weather.");
return;
}
Weather weather = weatherResult.getWeather();
Log.i(TAG, "Weather: " + weather);
}
});
Please refer here for description of the Weather class whose instance is returned by the API.
The advantage of using this is that you can massively simplify your code, avoid having to manage location requests and call the API as often as needed (I believe it has a cache to avoid too many network requests that are battery draining).

how I can get the city name of my current position?

I'm working with android studio and in a popup dialog I want that users can get their position but all I know to do is get my latitude and longitude.
This is the code
import android.app.Activity;
import android.content.Context;
import android.location.Criteria;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements LocationListener {
private TextView latituteField;
private TextView longitudeField;
private LocationManager locationManager;
private String provider;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
latituteField = (TextView) findViewById(R.id.TextView02);
longitudeField = (TextView) findViewById(R.id.TextView04);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
System.out.println("Provider " + provider + " has been selected.");
onLocationChanged(location);
} else {
latituteField.setText("Location not available");
longitudeField.setText("Location not available");
}
}
#Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
#Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
#Override
public void onLocationChanged(Location location) {
int lat = (int) (location.getLatitude());
int lng = (int) (location.getLongitude());
latituteField.setText(String.valueOf(lat));
longitudeField.setText(String.valueOf(lng));
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "Disabled provider " + provider,
Toast.LENGTH_SHORT).show();
}
}
in the MainActivity.Can you help me?
I've added this in the manifest
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION"/>
but it still says "Location not available".

You need the GeoCoder class to get Address from a given Lat/Long. try the following:
Geocoder geoCoder = new Geocoder(this, Locale.getDefault()); //it is Geocoder
StringBuilder builder = new StringBuilder();
try {
List<Address> address = geoCoder.getFromLocation(latitude, longitude, 1);
int maxLines = address.get(0).getMaxAddressLineIndex();
for (int i=0; i<maxLines; i++) {
String addressStr = address.get(0).getAddressLine(i);
builder.append(addressStr);
builder.append(" ");
}
String fnialAddress = builder.toString(); //This is the complete address.
} catch (IOException e) {}
catch (NullPointerException e) {}
Code below should work for you: (Check the inline comments regarding your code)
import java.io.IOException;
import java.util.List;
import java.util.Locale;
import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity implements LocationListener {
private TextView latituteField;
private TextView longitudeField;
private TextView addressField; //Add a new TextView to your activity_main to display the address
private LocationManager locationManager;
private String provider;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
latituteField = (TextView) findViewById(R.id.TextView02);
longitudeField = (TextView) findViewById(R.id.TextView04);
addressField = (TextView) findViewById(R.id.TextView05); //Make sure you add this to activity_main
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);
if (location != null) {
System.out.println("Provider " + provider + " has been selected.");
onLocationChanged(location);
} else {
latituteField.setText("Location not available");
longitudeField.setText("Location not available");
}
}
#Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
#Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
#Override
public void onLocationChanged(Location location) {
//You had this as int. It is advised to have Lat/Loing as double.
double lat = location.getLatitude();
double lng = location.getLongitude();
Geocoder geoCoder = new Geocoder(this, Locale.getDefault());
StringBuilder builder = new StringBuilder();
try {
List<Address> address = geoCoder.getFromLocation(lat, lng, 1);
int maxLines = address.get(0).getMaxAddressLineIndex();
for (int i=0; i<maxLines; i++) {
String addressStr = address.get(0).getAddressLine(i);
builder.append(addressStr);
builder.append(" ");
}
String fnialAddress = builder.toString(); //This is the complete address.
latituteField.setText(String.valueOf(lat));
longitudeField.setText(String.valueOf(lng));
addressField.setText(fnialAddress); //This will display the final address.
} catch (IOException e) {
// Handle IOException
} catch (NullPointerException e) {
// Handle NullPointerException
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "Disabled provider " + provider,
Toast.LENGTH_SHORT).show();
}
}

You need to execute the Geocoder in a AsyncTask (or in a Thread not in the same ThreadGroup as the UI Thread)!
public void getCityName(final Location location, final OnGeocoderFinishedListener listener) {
new AsyncTask<Void, Integer, List<Address>>() {
#Override
protected List<Address> doInBackground(Void... arg0) {
Geocoder coder = new Geocoder(getContext(), Locale.ENGLISH);
List<Address> results = null;
try {
results = coder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
} catch (IOException e) {
// nothing
}
return results;
}
#Override
protected void onPostExecute(List<Address> results) {
if (results != null && listener != null) {
listener.onFinished(results);
}
}
}.execute();
}
With this abstract Listener
public abstract class OnGeocoderFinishedListener {
public abstract void onFinished(List<Address> results);
}
Now call the method like this:
getCityName(location, new OnGeocoderFinishedListener() {
#Override
public void onFinished(List<Address> results) {
// do something with the result
}
});
Hope this will help some of you!

You can use google api to get current location address. Check out my answer in this post go get your city.
How to get city name from latitude and longitude coordinates in Google Maps?

Getting longitude and latitude works in emulator but not on device?

I've been trying to work GPS coordinates but it's been a lot tougher than I thought. After a few hours of trial and error, I've managed to output the latitude and longitude (mocked) for my emulator. Below are the 2 ways I've done it:
First way:
import java.io.IOException;
import java.util.Calendar;
import java.util.List;
import java.util.Locale;
import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.widget.TextView;
public class MainActivity extends Activity
{
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String text = "";
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Location location = lm.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(location != null) {
showMyAddress(location);
}
final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
showMyAddress(location);
}
public void onProviderDisabled(String arg0) {
}
public void onProviderEnabled(String arg0) {
}
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
}
};
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 30000, 10, locationListener);
double longitude = location.getLongitude();
double latitude = location.getLatitude();
Log.i(TAG, "longitude: " + longitude);
Log.i(TAG, "latitude: " + latitude);
text = "longitude: " + longitude + ", " + "latitude: " + latitude;
TextView textView = (TextView) findViewById(R.id.txtvwMain);
textView.setText(text);
}
private void showMyAddress(Location location) {
double latitude = location.getLatitude();
double longitude = location.getLongitude();
Geocoder myLocation = new Geocoder(getApplicationContext(), Locale.getDefault());
List<Address> myList;
try {
myList = myLocation.getFromLocation(latitude, longitude, 1);
} catch (IOException e1) {
e1.printStackTrace();
}
}
}
Second way:
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class MainActivity extends Activity implements LocationListener
{
private LocationManager lm;
private TextView tv;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tv = (TextView) findViewById(R.id.txtvwMain);
lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 500, 1, this);
Location location = lm.getLastKnownLocation(lm.GPS_PROVIDER);
double longitude = location.getLongitude();
double latitude = location.getLatitude();
tv.setText("latitude="+latitude+", longitude="+longitude);
}
#Override
public void onLocationChanged(Location arg0) {
String lat = String.valueOf(arg0.getLatitude());
String lon = String.valueOf(arg0.getLongitude());
Log.e("GPS", "location changed: lat="+lat+", lon="+lon);
tv.setText("lat="+lat+", lon="+lon);
}
public void onProviderDisabled(String arg0) {
Log.e("GPS", "provider disabled " + arg0);
}
public void onProviderEnabled(String arg0) {
Log.e("GPS", "provider enabled " + arg0);
}
public void onStatusChanged(String arg0, int arg1, Bundle arg2) {
Log.e("GPS", "status changed to " + arg0 + " [" + arg1 + "]");
}
}
Both ways above work and print out the mock latitude and longitude onto a TextView in the emulator (running Android 4.2.2). However, when I upload the .apk file onto my device (tablet running Android 4.0.4), it just crashes. I don't know what's wrong because I can't see any error messages. What is the source of the problem and how may I go about solving it? Thanks.

how to get postal code using reverse geocoding in android

I am new to Andriod development..i try to get postal code and city name from reverse geocoding using below code.it finding latitude, longitude value fine but cant able to get cityname and postal code.
package com.example.code;
import java.io.IOException;
import java.util.List;
import java.util.Locale;
import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class LbsGeocodingActivity extends Activity {
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1000; // in Milliseconds
protected LocationManager locationManager;
protected Button retrieveLocationButton;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
retrieveLocationButton = (Button) findViewById(R.id.retrieve_location_button);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
new MyLocationListener()
);
retrieveLocationButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
showCurrentLocation();
}
});
}
protected void showCurrentLocation() {
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
Geocoder gcoder=new Geocoder(this, Locale.ENGLISH);
List<Address> Data = null;
double latitude;
double longitude;
if (location != null) {
latitude=location.getLatitude();
longitude=location.getLongitude();
try {
Data=gcoder.getFromLocation(latitude, longitude, 1);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String cityname=Data.get(0).getLocality();
String postalcode=Data.get(0).getPostalCode();
String message=String.format("City Name \n PostalCode \n", Data.get(0).getLocality(),Data.get(0).getPostalCode());
Toast.makeText(LbsGeocodingActivity.this,message ,
Toast.LENGTH_LONG).show();
}
}
private class MyLocationListener implements LocationListener {
public void onLocationChanged(Location location) {
String message = String.format(
"New Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
Toast.makeText(LbsGeocodingActivity.this, message, Toast.LENGTH_LONG).show();
}
public void onStatusChanged(String s, int i, Bundle b) {
Toast.makeText(LbsGeocodingActivity.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}
public void onProviderDisabled(String s) {
Toast.makeText(LbsGeocodingActivity.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}
public void onProviderEnabled(String s) {
Toast.makeText(LbsGeocodingActivity.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show(); }
}
}

It looks like your code for finding the city and zipcode is right, but your code for formatting the string for your toast is wrong. It does not put the values in there.
It should look like this:
String message=String.format("City Name %s \n PostalCode %d \n", Data.get(0).getLocality(),Data.get(0).getPostalCode());
The %s represents a string and the %s represents a decimal number (integer).

Incorrect Location updates with wifi/mobile network but not with GPS

Following is the coding i got from some one else work. I am trying to implement bit of his work with necessary changes in my app. The problem here is that it is not returning the proper address when the GET ADDRESS button is clicked. Besides, it works only with the wifi/mobile network but not with the GPS. Meanwhile, i wonder how to make auto-posting of data to sever when the call is making to a contact. Thank you!
package com.yang.address;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
public class AddressActivity extends Activity {
/** Called when the activity is first created. */
Double lat, lon;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btnLocation = (Button)findViewById(R.id.btnLocation);
btnLocation.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
// Acquire a reference to the system Location Manager
LocationManager locationManager = (LocationManager) AddressActivity.this.getSystemService(Context.LOCATION_SERVICE);
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
// Called when a new location is found by the network location provider.
lat = location.getLatitude();
lon = location.getLongitude();
TextView tv = (TextView) findViewById(R.id.txtLoc);
tv.setText("Your Location is:" + lat + "--" + lon);
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
// Register the listener with the Location Manager to receive location updates
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
}
});
Button btnSend = (Button)findViewById(R.id.btnSend);
btnSend.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
postData(lat, lon);
}
});
Button btnAdd = (Button)findViewById(R.id.btnAddress);
btnAdd.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
TextView tv = (TextView)findViewById(R.id.txtAddress);
tv.setText(GetAddress(lat, lon));
}
});
}
public void postData(Double lat2, Double lon2) {
// Create a new HttpClient and Post Header
HttpClient httpclient = new DefaultHttpClient();
HttpGet htget = new HttpGet("http://myappurl.com/Home/Book/"+lat2+"/"+lon2);
try {
// Execute HTTP Post Request
HttpResponse response = httpclient.execute(htget);
String resp = response.getStatusLine().toString();
Toast.makeText(this, resp, 5000).show();
} catch (ClientProtocolException e) {
Toast.makeText(this, "Error", 5000).show();
} catch (IOException e) {
Toast.makeText(this, "Error", 5000).show();
}
}
public String GetAddress(Double lat2, Double lon2)
{
Geocoder geocoder = new Geocoder(this, Locale.ENGLISH);
String ret = "";
try {
List<Address> addresses = geocoder.getFromLocation(lat2,lon2, 1);
if(addresses != null) {
Address returnedAddress = addresses.get(0);
StringBuilder strReturnedAddress = new StringBuilder("Address:\n");
for(int i=0; i<returnedAddress.getMaxAddressLineIndex(); i++) {
strReturnedAddress.append(returnedAddress.getAddressLine(i)).append("\n");
}
ret = strReturnedAddress.toString();
}
else{
ret = "No Address returned!";
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
ret = "Can't get Address!";
}
return ret;
}
}

Looks like you've made some progress since your last question.
First off, the LocationManager system on androids is Listening Service in that you register it as a listener and allow the OS to notify when updates are made. This means you should have the code you put in your OnClick method run before you need it. Your best option is to have the OnCreate method of your Activity register the listener as the Activity starts and use the onLocationChanged callback as a way to store the new Location on a class variable.
private Location lastKnownLocation;
private TextView tv;
public void onCreate(Bundle savedInstanceState) {
//....
setupLocationServices();
//....
tv = (TextView) findViewById(R.id.txtLoc);
Button btnLocation = (Button)findViewById(R.id.btnLocation);
btnLocation.setOnClickListener(new OnClickListener() {
public void onClick(View arg0) {
updateLocation();
}
});
//....
}
private void setupLocationServices() {
//....
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
// Called when a new location is found by the network location provider.
lastKnownLocation = location;
updateLocation();
}
....
}
private void updateLocation() {
double lat = lastKnownLocation.getLatitude();
double lat = lastKnownLocation.getLongitude();
tv.setText("Your Location is:" + lat + "--" + lon);
}
As for your reasoning as to why it doesn't work with GPS it is because you never register the GPS listener. Where you have this line:
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locationListener);
You would need to substitude in this value:
LocationManager.GPS_PROVIDER
Again, as I recommended before I really suggest taking the time to fully understand the Android Developer documentation
As for your other problem regarding listening to the state of incoming calls you should start off by checking the TelephonyManager documentation here. Specifically look for the use of ACTION_PHONE_STATE_CHANGED and its extras for incoming calls. For outgoing calls google the use of ACTION_NEW_OUTGOING_CALL Intents.