谷歌地图 v2 获取我的位置

Question

它在运行时给我错误关闭虚拟机

这里是logcat

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

代码：

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

我想你忘了initialized你的Google Map Object像这样

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

您的应用程序崩溃了，因为您是 gmap 在此位置是 NULL

 gmap.setMyLocationEnabled(true);

根据您的评论，您应该更改此设置

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

与

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

Answer 2

为什么你不在你的代码中初始化地图

在您的 OnCreate 方法中执行此操作

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();