Android gMap v2 Camera Animate 上的 NPE

Question

我的一项活动为用户位置运行简单的相机更新时遇到一个奇怪的错误。

这里是日志猫错误信息：

12-23 21:44:11.075: V/LAT/LON(3373): Lat:40.28031 | Lon:-120.50508
12-23 21:44:11.075: W/System.err(3373): java.lang.NullPointerException
12-23 21:44:11.075: W/System.err(3373):     at com.jasonflaherty.snoteldata.NOAASnowDepthSites.animateCameraTo(NOAASnowDepthSites.java:654)
12-23 21:44:11.075: W/System.err(3373):     at com.jasonflaherty.snoteldata.NOAASnowDepthSites.showLocation(NOAASnowDepthSites.java:644)
12-23 21:44:11.075: W/System.err(3373):     at com.jasonflaherty.snoteldata.NOAASnowDepthSites.onCreate(NOAASnowDepthSites.java:106)
12-23 21:44:11.075: W/System.err(3373):     at android.app.Activity.performCreate(Activity.java:5231)
12-23 21:44:11.075: W/System.err(3373):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
12-23 21:44:11.075: W/System.err(3373):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
12-23 21:44:11.075: W/System.err(3373):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
12-23 21:44:11.075: W/System.err(3373):     at android.app.ActivityThread.access$800(ActivityThread.java:135)
12-23 21:44:11.075: W/System.err(3373):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
12-23 21:44:11.075: W/System.err(3373):     at android.os.Handler.dispatchMessage(Handler.java:102)
12-23 21:44:11.075: W/System.err(3373):     at android.os.Looper.loop(Looper.java:136)
12-23 21:44:11.075: W/System.err(3373):     at android.app.ActivityThread.main(ActivityThread.java:5017)
12-23 21:44:11.075: W/System.err(3373):     at java.lang.reflect.Method.invokeNative(Native Method)
12-23 21:44:11.075: W/System.err(3373):     at java.lang.reflect.Method.invoke(Method.java:515)
12-23 21:44:11.083: W/System.err(3373):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
12-23 21:44:11.083: W/System.err(3373):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
12-23 21:44:11.083: W/System.err(3373):     at dalvik.system.NativeStart.main(Native Method)
12-23 21:44:11.137: W/ActivityThread(3373): ClassLoader.loadClass: The class loader returned by Thread.getContextClassLoader() may fail for processes that host multiple applications. You should explicitly specify a context class loader. For example: Thread.setContextClassLoader(getClass().getClassLoader());
12-23 21:44:11.145: W/ResourceType(3373): getEntry failing because entryIndex 13 is beyond type entryCount 1
12-23 21:44:11.145: W/ResourceType(3373): Failure getting entry for 0x7f0b000d (t=10 e=13) in package 0 (error -2147483647)

如您所见，应用程序返回纬度/经度，但随后我在 animate 或那里得到错误...这是我的 showLocation() 代码：

float lat = new LocationInfo(getBaseContext()).lastLat;
        float lon = new LocationInfo(getBaseContext()).lastLong;

        Log.v("LAT/LON", "Lat:" + lat + " | Lon:" + lon);

        try {
            LatLng meLoc = new LatLng(lat, lon);
            CameraPosition cameraPosition = new CameraPosition.Builder()
                    .target(meLoc) // Sets the center of the map to
                    .zoom(ZP).bearing(0).tilt(80).build();
            map.animateCamera(CameraUpdateFactory
                    .newCameraPosition(cameraPosition));
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

它特别失败：

map.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));

我是从https://developers.google.com/maps/documentation/android/views#updating_the_camera_view得到的

无论如何...有什么想法吗？！我很困惑。

Answer 1

您在哪里调用此代码？如果它在 onCreate() 中，则地图尚未实例化（直到 onCreateView 之后）。尝试在 onStart() 或 onResume() 中更新相机位置。