Question

目前我正在开发一个android的应用程序。但我有一个问题。

方案如下：

1）启动一个应用程序

2）选择关于google map v2的标签

3）单击Keycode_back完成应用程序。

4）然后我可以从ADT的LogCat看到有关java.lang.NullPointerException的错误消息。

public class Fragment_Section1 extends Fragment {

public Fragment_Section1() {
    // TODO Auto-generated constructor stub
}

GoogleMap gMap;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    // inflat and return the layout
    View rootView = inflater.inflate(R.layout.layout_fragment_section1,
            container, false);

    GoogleMap gMap = ((SupportMapFragment) getFragmentManager()
            .findFragmentById(R.id.mapView)).getMap();

    // To configure any camera updates here

    LatLng ku = new LatLng(37.545833, 127.082778);

    // gMap.setMyLocationEnabled(true);
    gMap.moveCamera(CameraUpdateFactory.newLatLngZoom(ku, 15));

    // gMap.addMarker(new MarkerOptions().title("KU")
    // .snippet("The most populous city in Australia.").position(ku));

    return rootView;
}

public void onDestroyView() {
    SupportMapFragment smf = (SupportMapFragment) getFragmentManager()
            .findFragmentById(R.id.mapView);
    if (smf != null)
        getFragmentManager().beginTransaction().remove(smf)
                .commitAllowingStateLoss();
    super.onDestroyView();
}
}

布局：layout_fragment_section1.xml

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

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

</LinearLayout>

LogCat：

12-18 14:39:03.034: D/AndroidRuntime(24730): Shutting down VM
12-18 14:39:03.034: W/dalvikvm(24730): threadid=1: thread exiting with uncaught exception (group=0x424f9700)
12-18 14:39:03.034: E/AndroidRuntime(24730): FATAL EXCEPTION: main
12-18 14:39:03.034: E/AndroidRuntime(24730): java.lang.NullPointerException
12-18 14:39:03.034: E/AndroidRuntime(24730): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1435)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:440)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at android.os.Handler.handleCallback(Handler.java:730)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at android.os.Handler.dispatchMessage(Handler.java:92)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at android.os.Looper.loop(Looper.java:137)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at android.app.ActivityThread.main(ActivityThread.java:5493)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at java.lang.reflect.Method.invokeNative(Native Method)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at java.lang.reflect.Method.invoke(Method.java:525)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1209)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1025)
12-18 14:39:03.034: E/AndroidRuntime(24730):    at dalvik.system.NativeStart.main(Native Method)

你能给我一个建议吗？

如果您需要任何信息，请告诉我。

最诚挚的问候，

Fragment中的java.lang.NullPointerException

0 个答案: