如何使用locationclient类和requestLocationUpdates(LocationRequest, LocationListener)来获取android中的位置更新？我已经尝试了以下代码，但它无法正常工作。谁能帮我这个？哪里是错误，提前谢谢。
public class MainActivity extends FragmentActivity implements GooglePlayServicesClient.ConnectionCallbacks,GooglePlayServicesClient.OnConnectionFailedListener {
private final static int CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
LocationClient mLocationClient;
Location mCurrentLocation;
LocationRequest mLocationRequest;
ArrayList<Location> list = new ArrayList<Location>();
private static String msg;
private static final int MILLISECONDS_PER_SECOND = 1000; // Milliseconds per second
public static final int UPDATE_INTERVAL_IN_SECONDS = 300;// Update frequency in seconds
private static final long UPDATE_INTERVAL = MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS; // Update frequency in milliseconds
private static final int FASTEST_INTERVAL_IN_SECONDS = 60; // The fastest update frequency, in seconds
// A fast frequency ceiling in milliseconds
private static final long FASTEST_INTERVAL = MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;
//private EditText text;
public static class ErrorDialogFragment extends DialogFragment {
private Dialog mDialog;
public ErrorDialogFragment() {
super();
mDialog = null; // Default constructor. Sets the dialog field to null
}
public void setDialog(Dialog dialog) {
mDialog = dialog; // Set the dialog to display
}
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
return mDialog; // Return a Dialog to the DialogFragment.
}
}
private final class MyLocationListener implements LocationListener {
@Override
public void onLocationChanged(Location location) {
// Report to the UI that the location was updated
mCurrentLocation =location;
Context context = getApplicationContext();
msg = Double.toString(location.getLatitude()) + "," + Double.toString(location.getLongitude());
list.add(mCurrentLocation);
Toast.makeText(context, msg,Toast.LENGTH_LONG).show();
}
}
@Override
protected void onActivityResult(
int requestCode, int resultCode, Intent data) {
// Decide what to do based on the original request code
switch (requestCode) {
case CONNECTION_FAILURE_RESOLUTION_REQUEST :
/*
* If the result code is Activity.RESULT_OK, try
* to connect again
*/
switch (resultCode) {
case Activity.RESULT_OK :
/*
* Try the request again
*/
break;
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mLocationClient = new LocationClient(this, this, this); /* Create a new location client, using the enclosing class to handle callbacks */
mLocationClient.connect();
mLocationRequest = LocationRequest.create();
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY); // Use high accuracy
mLocationRequest.setInterval(UPDATE_INTERVAL); // Setting the update interval to 5mins
mLocationRequest.setFastestInterval(FASTEST_INTERVAL); // Set the fastest update interval to 1 min
LocationListener locationListener = new MyLocationListener();
mLocationClient.requestLocationUpdates(mLocationRequest,locationListener);
}
@Override
protected void onDestroy() {
mLocationClient.disconnect();
}
/* Called by Location Services when the request to connect the client finishes successfully. At this point, you can request the current location or start periodic updates */
@Override
public void onConnected(Bundle dataBundle) {
}
/* Called by Location Services if the connection to the location client drops because of an error.*/
@Override
public void onDisconnected() {
Toast.makeText(this, "Disconnected. Please re-connect.",
Toast.LENGTH_SHORT).show();
}
//Called by Location Services if the at tempt to Location Services fails.
@Override
public void onConnectionFailed(ConnectionResult connectionResult) {
/*
* Google Play services can resolve some errors it detects.If the error has a resolution, try sending an Intent to start a Google Play services activity that can resolve
* error. */
if (connectionResult.hasResolution()) {
try {
// Start an Activity that tries to resolve the error
connectionResult.startResolutionForResult(this,CONNECTION_FAILURE_RESOLUTION_REQUEST);
/*
* Thrown if Google Play services canceled the original
* PendingIntent
*/
} catch (IntentSender.SendIntentException e) {
e.printStackTrace();
}
} else {
/* * If no resolution is available, display a dialog to the user with the error. */
showErrorDialog(connectionResult.getErrorCode());
}
}
private boolean showErrorDialog(int errorCode) {
int resultCode =
GooglePlayServicesUtil.
isGooglePlayServicesAvailable(this);
// If Google Play services is available
if (ConnectionResult.SUCCESS == resultCode) {
// In debug mode, log the status
// Continue
return true;
// Google Play services was not available for some reason
} else {
Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog(errorCode,this,
CONNECTION_FAILURE_RESOLUTION_REQUEST);
// If Google Play services can provide an error dialog
if (errorDialog != null) {
// Create a new DialogFragment for the error dialog
ErrorDialogFragment errorFragment = new ErrorDialogFragment();
// Set the dialog in the DialogFragment
errorFragment.setDialog(errorDialog);
// Show the error dialog in the DialogFragment
errorFragment.show(getSupportFragmentManager(),"Location Updates");
} return false;
}
}
}
答案 0 :(得分：7)
LocationClient.connect（）是异步的。在连接完成之前，您无法立即开始使用客户端方法。你应该在onConnected回调中调用requestLocationUpdates（或至少在调用回调之后）。
答案 1 :(得分：0)
您应该在onConnected（）回调中请求位置更新。您可以看到我的代码here供您参考。希望它会有所帮助。