在我的应用程序中,连接到locationservices.api后,在onconnected()回调中,我启动了一个位置更新请求,问题是处理进程的活动(dataactivity)无法识别为locationlistener的实例,它显示一个错误,并建议强制转换。
protected void startLocationUpdates() {
PendingResult locationUpdatesResult = LocationServices.FusedLocationApi.requestLocationUpdates(locationGoogleApiClient, locationRequest, (com.google.android.gms.location.LocationListener) this);
}
当我将最后一个参数转换为(com.google.android.gms.location.locationListener)时,IDE允许我编译,但是抛出了一个ClassCastException
java.lang.ClassCastException:com.example。[…].dataactivity不能转换为com.google.android.gms.location.locationListener
我真的不知道为什么会这样。
这是这个班的声明。
public class DataActivity extends FragmentActivity implements LocationListener, ConnectionCallbacks , OnConnectionFailedListener, OnMapReadyCallback{
oncreate():
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_data);
//Create the GoogleLocationAPI reference
buildGoogleLocationApiClient();
//Create Location Request
createLocationRequest();
//Initialize the mapFragment
initializeMapFragment();
updateUI();
}
其他方法:
protected synchronized void buildGoogleLocationApiClient(){
locationGoogleApiClient = new GoogleApiClient.Builder(this)
.addApi(LocationServices.API)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.build();
locationGoogleApiClient.connect();
Log.v("**INFO: ", "API CLIENT");
}
protected static void createLocationRequest() {
locationRequest = new LocationRequest();
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
locationRequest.setInterval(10000);
locationRequest.setFastestInterval(5000);
Log.i("**INFO: ", "LocationRequest created");
}
protected void initializeMapFragment(){
//Initialize the mapFragment
mapFragment = (MapFragment) getFragmentManager().findFragmentById(R.id.map);
//When mapFragment is ready...
mapFragment.getMapAsync(this);
}
所以当建立连接(onconnected)时,当错误弹出时,我调用这个方法。
protected void startLocationUpdates() {
PendingResult locationUpdatesResult = LocationServices.FusedLocationApi.requestLocationUpdates(locationGoogleApiClient, locationRequest, this);
locationUpdatesResult.await();
}
最佳答案
确保DataActivity
实现com.google.android.gms.location.LocationListener
而不是android.location.LocationListener
。
您可能错误地导入了android.location.LocationListener
。