NPE on Android gMap v2 Camera Animate

Question

我在为用户位置运行简单相机更新的一个活动中收到一个奇怪的错误。

以下是日志猫错误信息：

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，该应用程序返回纬度/纬度，但随后我在 animate 或那里收到错误......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));

我从以下方面得到的： https://developers.google.com/maps/documentation/android/views#updating_the_camera_view

无论如何。。。有什么想法吗？！我很困惑。

Answer 1

你在哪里调用这个代码？ 如果它在 onCreate（） 中，则映射尚未实例化（直到 onCreateView 之后）。 尝试在 onStart（） 或 onResume（） 中更新相机位置。