Basic:
After connecting the client apps to the location sensor and retrieve the client's current address then if you wants to get updates about your location in some particular interval time then you can turn on the updates.client wants to turn off the updates then they can do the onpause() method for getting update.Here location object contain the longitude and latitude coordinates.these coordinates useful for the calculating map position and location of the client.
How to discover address:
for discover the the address we just need one progress bar and one text view in to the our main xml file progress bar shows the process of connecting the client position.for show intermediate activity tat show your app is working in background Set the initial state android:visibility="gone" to a make invisible and remove it from hierarchy.
<ProgressBar android:id="@+id/address_progress" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:indeterminate="true" android:visibility="gone" />
Here create the subclass of that AsyncTask calls getFromLocation() the and return the address.define the text object maddress to contain the address and a progress bar object that you to control the intermediate activity indicator.
public class MainActivity extends FragmentActivity {
...
private TextView mAddress;
private ProgressBar mActivityIndicator;
...
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
mAddress = (TextView) findViewById(R.id.address);
mActivityIndicator =
(ProgressBar) findViewById(R.id.address_progress);
}
...
/**
* A subclass of AsyncTask that calls getFromLocation() in the
* background. The class definition has these generic types:
* Location - A Location object containing
* the current location.
* Void - indicates that progress units are not used
* String - An address passed to onPostExecute()
*/
private class GetAddressTask extends
AsyncTask<Location, Void, String> {
Context mContext;
public GetAddressTask(Context context) {
super();
mContext = context;
}
...
/**
* Get a Geocoder instance, get the latitude and longitude
* look up the address, and return it
*
* @params params One or more Location objects
* @return A string containing the address of the current
* location, or an empty string if no address can be found,
* or an error message
*/
@Override
protected String doInBackground(Location... params) {
Geocoder geocoder =
new Geocoder(mContext, Locale.getDefault());
// Get the current location from the input parameter list
Location loc = params[0];
// Create a list to contain the result address
List<Address> addresses = null;
try {
/*
* Return 1 address.
*/
addresses = geocoder.getFromLocation(loc.getLatitude(),
loc.getLongitude(), 1);
} catch (IOException e1) {
Log.e("LocationSampleActivity",
"IO Exception in getFromLocation()");
e1.printStackTrace();
return ("IO Exception trying to get address");
} catch (IllegalArgumentException e2) {
// Error message to post in the log
String errorString = "Illegal arguments " +
Double.toString(loc.getLatitude()) +
" , " +
Double.toString(loc.getLongitude()) +
" passed to address service";
Log.e("LocationSampleActivity", errorString);
e2.printStackTrace();
return errorString;
}
// If the reverse geocode returned an address
if (addresses != null && addresses.size() > 0) {
// Get the first address
Address address = addresses.get(0);
/*
* Format the first line of address (if available),
* city, and country name.
*/
String addressText = String.format(
"%s, %s, %s",
// If there's a street address, add it
address.getMaxAddressLineIndex() > 0 ?
address.getAddressLine(0) : "",
// Locality is usually a city
address.getLocality(),
// The country of the address
address.getCountryName());
// Return the text
return addressText;
} else {
return "No address found";
}
}
...
}
...
}
Method of display results:
doInBackground() this method return the result as string form.then this value pass in to onpostexecute().this onpostexecute() method run over the UI tread. this method call during the method retrieve something in back ground process. after gain the result this indicator turn off and display the result.
private class GetAddressTask extends AsyncTask<Location, Void, String> { ... /** * A method that's called once doInBackground() completes. Turn * off the indeterminate activity indicator and set * the text of the UI element that shows the address. If the * lookup failed, display the error message. */ @Override protected void onPostExecute(String address) { // Set activity indicator visibility to "gone" mActivityIndicator.setVisibility(View.GONE); // Display the results of the lookup. mAddress.setText(address); } ... }
Lookup task:
to get the execute() click on the button . after ten indicator display the application is now working . after then this process get the address using this coding .for get the address here geocoder services used.
public class MainActivity extends FragmentActivity { ... /** * The "Get Address" button in the UI is defined with * android:onClick="getAddress". The method is invoked whenever the * user clicks the button. * * @param v The view object associated with this method, * in this case a Button. */ public void getAddress(View v) { // Ensure that a Geocoder services is available if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD && Geocoder.isPresent()) { // Show the activity indicator mActivityIndicator.setVisibility(View.VISIBLE); /* * Reverse geocoding is long-running and synchronous. * Run it on a background thread. * Pass the current location to the background task. * When the task finishes, * onPostExecute() displays the address. */ (new GetAddressTask(this)).execute(mLocation); } ... } ... }
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