我正在尝试构建一个应用程序，它会在googleMap中显示我的位置，并会每隔几秒更新一次我的位置。
这是我的代码：
public class MapsActivity extends FragmentActivity implements
ConnectionCallbacks, OnConnectionFailedListener, LocationListener, OnMapReadyCallback {
protected static final String TAG = "location-updates-sample";
/**
* The desired interval for location updates. Inexact. Updates may be more or less frequent.
*/
public static final long UPDATE_INTERVAL_IN_MILLISECONDS = 10000;
/**
* The fastest rate for active location updates. Exact. Updates will never be more frequent
* than this value.
*/
public static final long FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS =
UPDATE_INTERVAL_IN_MILLISECONDS / 2;
// Keys for storing activity state in the Bundle.
protected final static String REQUESTING_LOCATION_UPDATES_KEY = "requesting-location-updates-key";
protected final static String LOCATION_KEY = "location-key";
protected GoogleApiClient mGoogleApiClient;
protected LocationRequest mLocationRequest;
protected Location mCurrentLocation;
/**
* Tracks the status of the location updates request. Value changes when the user presses the
* Start Updates and Stop Updates buttons.
*/
protected Boolean mRequestingLocationUpdates;
private GoogleMap mMap;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
mRequestingLocationUpdates = false;
updateValuesFromBundle(savedInstanceState);
buildGoogleApiClient();
}
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
LatLng loc = new LatLng(-34,151);
mMap.addMarker(new MarkerOptions().position(loc).title("my location"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(loc));
startUpdates();
}
private void updateValuesFromBundle(Bundle savedInstanceState) {
Log.i(TAG, "Updating values from bundle");
if (savedInstanceState != null) {
if (savedInstanceState.keySet().contains(REQUESTING_LOCATION_UPDATES_KEY)) {
mRequestingLocationUpdates = savedInstanceState.getBoolean(
REQUESTING_LOCATION_UPDATES_KEY);
}
// Update the value of mCurrentLocation from the Bundle and update the UI to show the
// correct latitude and longitude.
if (savedInstanceState.keySet().contains(LOCATION_KEY)) {
// Since LOCATION_KEY was found in the Bundle, we can be sure that mCurrentLocation
// is not null.
mCurrentLocation = savedInstanceState.getParcelable(LOCATION_KEY);
}
updateUI();
}
}
protected synchronized void buildGoogleApiClient() {
Log.i(TAG, "Building GoogleApiClient");
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
createLocationRequest();
}
protected void createLocationRequest() {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setFastestInterval(FASTEST_UPDATE_INTERVAL_IN_MILLISECONDS);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
public void startUpdates() { // start updating location
if (!mRequestingLocationUpdates) {
mRequestingLocationUpdates = true;
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
}
public void stopUpdates() { // stop updating location
if (mRequestingLocationUpdates) {
mRequestingLocationUpdates = false;
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
}
/**
* Updates the latitude, the longitude, and the last location time in the UI.
*/
private void updateUI() {
LatLng loc = new LatLng(mCurrentLocation.getLatitude(), mCurrentLocation.getLongitude());
mMap.addMarker(new MarkerOptions().position(loc).title("my location"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(loc));
}
@Override
protected void onStart() {
super.onStart();
mGoogleApiClient.connect();
}
@Override
public void onResume() {
super.onResume();
if (mGoogleApiClient.isConnected() && mRequestingLocationUpdates) {
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
}
@Override
protected void onPause() {
super.onPause();
// Stop location updates to save battery, but don't disconnect the GoogleApiClient object.
if (mGoogleApiClient.isConnected()) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
}
@Override
protected void onStop() {
mGoogleApiClient.disconnect();
super.onStop();
}
/**
* Runs when a GoogleApiClient object successfully connects.
*/
@Override
public void onConnected(Bundle connectionHint) {
Log.i(TAG, "Connected to GoogleApiClient");
if (mCurrentLocation == null) {
mCurrentLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
updateUI();
}
if (mRequestingLocationUpdates) {
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
}
@Override
public void onLocationChanged(Location location) {
mCurrentLocation = location;
updateUI();
Toast.makeText(this, getResources().getString(R.string.location_updated_message),
Toast.LENGTH_SHORT).show();
}
@Override
public void onConnectionSuspended(int cause) {
// The connection to Google Play services was lost for some reason. We call connect() to
// attempt to re-establish the connection.
Log.i(TAG, "Connection suspended");
mGoogleApiClient.connect();
}
@Override
public void onConnectionFailed(ConnectionResult result) {
// Refer to the javadoc for ConnectionResult to see what error codes might be returned in
// onConnectionFailed.
Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = " + result.getErrorCode());
}
/**
* Stores activity data in the Bundle.
*/
public void onSaveInstanceState(Bundle savedInstanceState) {
savedInstanceState.putBoolean(REQUESTING_LOCATION_UPDATES_KEY, mRequestingLocationUpdates);
savedInstanceState.putParcelable(LOCATION_KEY, mCurrentLocation);
super.onSaveInstanceState(savedInstanceState);
}
}
此代码是谷歌示例代码的一部分，但我更改了一些内容并添加了googleMap，它只是在onMapReady（）之后崩溃。
stacktrace：
java.lang.IllegalStateException: GoogleApiClient is not connected yet.
at com.google.android.gms.common.api.internal.zzh.zzb(Unknown Source)
at com.google.android.gms.common.api.internal.zzl.zzb(Unknown Source)
at com.google.android.gms.common.api.internal.zzj.zzb(Unknown Source)
at com.google.android.gms.location.internal.zzd.requestLocationUpdates(Unknown Source)
at com.idanofek.photomap.MapsActivity.startUpdates(MapsActivity.java:135)
at com.idanofek.photomap.MapsActivity.onMapReady(MapsActivity.java:91)
at com.google.android.gms.maps.SupportMapFragment$zza$1.zza(Unknown Source)
at com.google.android.gms.maps.internal.zzo$zza.onTransact(Unknown Source)
at android.os.Binder.transact(Binder.java:387)
at com.google.android.gms.maps.internal.be.a(SourceFile:82)
at com.google.maps.api.android.lib6.e.fb.run(Unknown Source)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
答案 0 :(得分：1)
在执行任何操作之前，必须使用' connect（）'方法连接GoogleApiClient。在调用onConnected（Bundle）回调之前，客户端不被视为连接。
您应该在Activity的'onCreated(Bundle)'方法中实例化客户端对象，然后在 onStart（）上调用connect（）
您可以从 onConnected（）回调中调用 startLocationUpdate（）
@Override
public void onConnected(Bundle connectionHint) {
...
if (mRequestingLocationUpdates) {
startLocationUpdates();
}
}
protected void startLocationUpdates() {
LocationServices.FusedLocationApi.requestLocationUpdates(
mGoogleApiClient, mLocationRequest, this);
}
以下是有关位置更新的Google文档：http://developer.android.com/training/location/receive-location-updates.html