Google Map未加载Android-Java

Question

Here is what I have but my map is not loading and onMapLoaded is not being called

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

     <com.google.android.gms.maps.MapView android:id="@+id/mapView"
    android:layout_width="fill_parent"
    android:layout_height="80dp"
    android:layout_marginTop="30dp"/>

</RelativeLayout>

And then in my class I have

public class Activity extends Activity implements GoogleMap.OnMapLoadedCallback {

MapView mMap;
GoogleMap mGooleMap;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_resturant);

    mMap = (MapView) findViewById(R.id.mapView);
    mGooleMap = mMap.getMap();
}

@Override
public void onMapLoaded() {

    Log.i(TAG, "loaaded");
}
}

But the onMapLoaded is never called why?

Thanks for the help

EDIT

my xml is now this

<fragment
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/map"
        android:name="com.google.android.gms.maps.SupportMapFragment" />

And I also have

public class Activity extends FragmentActivity {

Answer 1

In Google Documentation they have given an example Google Map Example

You can implement OnMapReadyCallback listener which is given in sample app of google maps and override the onMapReady method as follows:-

public class YourCalssName extends AppCompatActivity implements OnMapReadyCallback {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.your_layout);  

     init(); //initialise MapFragment 
    .....
}

private void init() {
    SupportMapFragment mapFragment = (SupportMapFragment)getSupportFragmentManager().findFragmentById(R.id.map);
    mapFragment.getMapAsync(this); // Important to call this method for listener
}

@Override
    public void onMapReady(GoogleMap googleMap) {
        if (googleMap != null) {
            //Do whatever you want to do
        }
    }
}

And in your layout add Map Fragment as follows:-

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <fragment
            android:id="@+id/map"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            class="com.google.android.gms.maps.SupportMapFragment" 
            android:layout_marginBottom="10dp"/>

</LinearLayout>

Answer 2

Have you provided the GoogleMap V2 key? Along with the key, Google Map needs following permissions which you have to mention in your project's AppManifest.xml.

ACCESS_NETWORK_STATE – To check network state whether data can be downloaded or not
INTERNET – To check internet connection status
WRITE_EXTERNAL_STORAGE – To write to external storage as google maps store map data in external storage ACCESS_COARSE_LOCATION – To determine user's location using WiFi and mobile > cell data ACCESS_FINE_LOCATION – To determine user's location using GPS OpenGL
ES V2 – Required for Google Maps V2

If all the above mentioned requirements are fulfilled, this code snippet will help you. public class MainActivity extends Activity {

    // Google Map
    private GoogleMap googleMap;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        try {
            // Loading map
            initilizeMap();

        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    /**
     * function to load map. If map is not created it will create it for you
     * */
    private void initilizeMap() {
        if (googleMap == null) {
            googleMap = ((MapFragment) getFragmentManager().findFragmentById(
                    R.id.map)).getMap();

            // check if map is created successfully or not
            if (googleMap == null) {
                Toast.makeText(getApplicationContext(),
                        "Sorry! unable to create maps", Toast.LENGTH_SHORT)
                        .show();
            }
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        initilizeMap();
    }

}

PS Try that if(mGoogleMap == null) check to make sure that you do have an instance of Google map.