谷歌地圖V2讓我的位置

Question

它給我的錯誤在運行時關閉VM

這裏logcat的

06-12 13:37:52.844: I/u(6937): Making Creator dynamically 
06-12 13:37:53.675: I/Google Maps Android API(6937): Google Play services client version: 4452000 
06-12 13:37:53.705: I/Google Maps Android API(6937): Google Play services package version: 4452034 
06-12 13:37:55.287: I/fpp(6937): Making Creator dynamically 
06-12 13:37:55.287: I/Google Maps Android API(6937): Google Play services client version: 4452000 
06-12 13:37:55.507: D/dalvikvm(6937): GC_CONCURRENT freed 882K, 10% free 10018K/11043K, paused 28ms+13ms 
06-12 13:37:56.608: D/AndroidRuntime(6937): Shutting down VM 
06-12 13:37:56.608: W/dalvikvm(6937): threadid=1: thread exiting with uncaught exception (group=0x40aaa210) 
06-12 13:37:56.688: E/AndroidRuntime(6937): FATAL EXCEPTION: main 
06-12 13:37:56.688: E/AndroidRuntime(6937): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.appmap.appmap/com.appmap.appmap.MainActivity}: java.lang.NullPointerException 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1967) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1992) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.ActivityThread.access$600(ActivityThread.java:127) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1158) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.os.Handler.dispatchMessage(Handler.java:99) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.os.Looper.loop(Looper.java:137) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.ActivityThread.main(ActivityThread.java:4448) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at java.lang.reflect.Method.invokeNative(Native Method) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at java.lang.reflect.Method.invoke(Method.java:511) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:823) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:590) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at dalvik.system.NativeStart.main(Native Method) 
06-12 13:37:56.688: E/AndroidRuntime(6937): Caused by: java.lang.NullPointerException 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at com.appmap.appmap.MainActivity.onCreate(MainActivity.java:29) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.Activity.performCreate(Activity.java:4465) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1931) 
06-12 13:37:56.688: E/AndroidRuntime(6937):  ... 11 more 

代碼：

public class MainActivity extends FragmentActivity { 

private GoogleMap gmap; 

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






    /*if (savedInstanceState == null) { 
     getSupportFragmentManager().beginTransaction() 
       .add(R.id.container, new PlaceholderFragment()).commit(); 
    }*/ 
} 





@Override 
public boolean onCreateOptionsMenu(Menu menu) { 

    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
} 

@Override 
public boolean onOptionsItemSelected(MenuItem item) { 
    // Handle action bar item clicks here. The action bar will 
    // automatically handle clicks on the Home/Up button, so long 
    // as you specify a parent activity in AndroidManifest.xml. 
    int id = item.getItemId(); 
    if (id == R.id.action_settings) { 
     return true; 
    } 
    return super.onOptionsItemSelected(item); 


} 

/** 
* A placeholder fragment containing a simple view. 
*/ 
public static class PlaceholderFragment extends Fragment { 

    public PlaceholderFragment() { 
    } 

    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
      Bundle savedInstanceState) { 
     View rootView = inflater.inflate(R.layout.fragment_main, container, 
       false); 
     return rootView; 
    } 
} 
} 

Answer 1

爲什麼你不intializing在您的代碼地圖

在您的OnCreate方法中執行此操作

support_map_fragment = (SupportMapFragment) getSupportFragmentManager() 
       .findFragmentById(R.id.map); 
     googlemap = support_map_fragment.getMap(); 

     googlemap.setMapType(GoogleMap.MAP_TYPE_NORMAL); 


     googlemap.setMyLocationEnabled(true); 
     googlemap.getMyLocation(); 

Answer 2

我想你忘記initialized您Google Map Object像所以

SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map); 
GoogleMap gmap = fm.getMap(); 

您的應用程序崩潰，因爲你gmap是NULL在這個位置

gmap.setMyLocationEnabled(true); 

根據您的意見，你應該改變這種

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

與

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