运行稍微修改的谷歌地图示例会在谷歌地图代码中抛出BadParcelableException
。LatLng
类是可分包的,但找不到。似乎谷歌地图代码正在尝试解包未由它包裹的对象。什么情况会出现问题?
package com.example.mapdemo;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.MapView;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import android.os.Bundle;
public class RawMapViewDemoActivity extends android.support.v4.app.FragmentActivity {
private MapView mMapView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.raw_mapview_demo);
mMapView = (MapView) findViewById(R.id.map);
mMapView.onCreate(savedInstanceState);
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
mMapView.onSaveInstanceState(outState);
outState.putParcelable("marker", new LatLng(0, 0));
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
LatLng ll = savedInstanceState.getParcelable("marker");
}
}
。
FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity
ComponentInfo{com.example.mapdemo/com.example.mapdemo.RawMapViewDemoActivity}:
android.os.BadParcelableException: ClassNotFoundException when unmarshalling:
com.google.android.gms.maps.model.LatLng
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1647)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:2832)
at android.app.ActivityThread.access$1600(ActivityThread.java:117)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:130)
at android.app.ActivityThread.main(ActivityThread.java:3683)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:507)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.os.BadParcelableException:
ClassNotFoundException when unmarshalling: com.google.android.gms.maps.model.LatLng
at android.os.Parcel.readParcelable(Parcel.java:1958)
at android.os.Parcel.readValue(Parcel.java:1846)
at android.os.Parcel.readMapInternal(Parcel.java:2083)
at android.os.Bundle.unparcel(Bundle.java:208)
at android.os.Bundle.getBundle(Bundle.java:1078)
at com.google.android.gms.maps.internal.MapStateHelper
.getParcelableFromMapStateBundle(MapStateHelper.java:41)
at maps.y.ae.a(Unknown Source)
at maps.y.bm.onCreate(Unknown Source)
at com.google.android.gms.maps.internal.IMapViewDelegate$Stub
.onTransact(IMapViewDelegate.java:66)
at android.os.Binder.transact(Binder.java:279)
at com.google.android.gms.maps.internal.IMapViewDelegate$a$a
.onCreate(Unknown Source)
at com.google.android.gms.maps.MapView$b.onCreate(Unknown Source)
at com.google.android.gms.internal.c$3.a(Unknown Source)
at com.google.android.gms.internal.i.b(Unknown Source)
at com.google.android.gms.maps.MapView$a.a(Unknown Source)
at com.google.android.gms.maps.MapView$a.a(Unknown Source)
at com.google.android.gms.internal.c.a(Unknown Source)
at com.google.android.gms.internal.c.onCreate(Unknown Source)
at com.google.android.gms.maps.MapView.onCreate(Unknown Source)
at com.example.mapdemo.RawMapViewDemoActivity
.onCreate(RawMapViewDemoActivity.java:40)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611)
... 12 more
只是为了补充这里的现有答案,在打电话之前,我一直在从保存状态中删除我的包裹mapView.onCreate
并且它工作正常。
但是,在我的片段中添加ViewPager
后,我没有意识到BadParcelableException
已经返回并且代码已投入生产。事实证明,ViewPager
也保存了它的状态,并且因为它是支持库的一部分,所以谷歌地图找不到要解包它的类。
因此,我选择反转该过程,而不是从我知道的捆绑包中删除包裹,而是选择创建一个新的捆绑包,用于仅复制地图的状态。
private final static String BUNDLE_KEY_MAP_STATE = "mapData";
@Override
public void onSaveInstanceState(Bundle outState) {
// Save the map state to it's own bundle
Bundle mapState = new Bundle();
mapView.onSaveInstanceState(mapState);
// Put the map bundle in the main outState
outState.putBundle(BUNDLE_KEY_MAP_STATE, mapState);
super.onSaveInstanceState(outState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_map, container, false);
mapView = (MapView) view.findViewById(R.id.mapView);
mapView.getMapAsync(this);
Bundle mapState = null;
if (savedInstanceState != null) {
// Load the map state bundle from the main savedInstanceState
mapState = savedInstanceState.getBundle(BUNDLE_KEY_MAP_STATE);
}
mapView.onCreate(mapState);
return view;
}
我尝试了前两个答案但没有成功,但我找到了另一种解决方法:
保存状态时,在将数据添加到捆绑包之前,请注意转发 MapView.onSaveInstanceState 调用(您做得很好):
@Override
public void onSaveInstanceState(Bundle outState) {
// Forward the call BEFORE adding our LatLng array, else it will crash :
_mapView.onSaveInstanceState(outState);
// Put your Parcelable in the bundle:
outState.putParcelableArray("myLatLng", new LatLng(0, 0) );
}
在onCreate/onRestore中恢复状态时,请检查捆绑包是否不为空,如果是,请获取您的包裹,然后在转接呼叫之前将其从捆绑包中删除:
@Override
public void onCreate(Bundle savedInstanceState) {
// If the bundle is not null, get your Parcelable :
LatLng myLatLng = null;
if(savedInstanceState != null) {
myLatLng = (LatLng) savedInstanceState.getParcelable("myLatLng");
// Remove your Parcelable from the bundle, else it will crash :
savedInstanceState.remove("myLatLng");
}
// Forward the call :
_mapView.onCreate(savedInstanceState);
setUpMapIfNeeded();
}
此问题已在此处 code.google.com 提交,以防您想加注星标。
与此同时,我已经设法解决这个问题,只需将我的包裹添加到捆绑包中,然后再将其添加到最终的 onSaveInstanceState 捆绑包中。 这是有效的,因为捆绑包是MapView的内部类加载器的已知类。
我创建了两个非常小的实用程序来为我执行此操作。 这是代码
public static Parcelable unbundleParcelable(String key, Bundle src) {
Bundle b = src.getBundle(key);
if (b != null) {
return b.getParcelable("bundle_parcelable_util_key");
}
return null;
}
public static void bundleParcelable(String key, Bundle dest, Parcelable parcelable) {
Bundle b = new Bundle();
b.putParcelable("bundle_parcelable_util_key", parcelable);
dest.putBundle(key, b);
}
我已经修改了上一篇文章中的代码以使用我的临时解决方案。 这是我如何使用它。
@Override
public void onSaveInstanceState(Bundle outState) {
// Forward the call BEFORE adding our LatLng array, else it will crash :
_mapView.onSaveInstanceState(outState);
// Put your Parcelable in the bundle:
bundleParcelable("myLatLng", outState, new LatLng(0, 0));
}
@Override
public void onCreate(Bundle savedInstanceState) {
// Forward the call :
_mapView.onCreate(savedInstanceState);
LatLng myLatLng = null;
if(savedInstanceState != null) {
// Extract your Parcelable
myLatLng = (LatLng) unbundleParcelable("myLatLng", savedInstanceState);
}
setUpMapIfNeeded();
}
这应该适用于您在项目中使用的任何自定义包裹。
我找到了一个解决方法(有点)。在它发生的地方,只是尝试第二次这样做。它总是捕获异常,第二次问题似乎没有发生在这个地方。这对我有用。
try {
mapIntent.putExtra(Intents.EXTRA_LATLNG, new LatLng(
store.getLatitude(), store.getLongitude()));
} catch (BadParcelableException e) {
mapIntent.putExtra(Intents.EXTRA_LATLNG, new LatLng(
store.getLatitude(), store.getLongitude()));
}
我找到了更简单的解决方法。在执行任何操作之前,将片段或活动的类装入器提供给捆绑包:
savedInstanceState.setClassLoader(getClass().getClassLoader());
当直接传递到MapFragment或MapView的onCreateView或onCreate时,这似乎不起作用,因此您必须手动划分地图的CameraPosition并将空捆绑包传递到这些函数中。
当我离开我的应用程序时,我还有一个BadParcelableException(FragmentActivity带有选项卡,每个选项卡中都有一个Fragment)。我通过先打电话mapmpvMap.onSaveInstanceState(outState);
然后打电话super.onSaveInstanceState(outState);
来解决这个问题