android - fragment -InstantiationException : no empty Constructor -> Google Maps v2?

通过“应用程序更改”按钮再次打开已关闭的应用程序时，出现以下错误消息:

Caused by: java.lang.InstantiationException: can't instantiate class com.*.FragmentContact$1; no empty constructor

我发现了一些关于内部类并使它们静态化的技巧。但是，这个FragmentContact是 * .java文件中的公共(public)类，而具有公共(public)的空构造函数。
我在此项目中使用的是Google Maps Api v2，并在互联网上的某处进行了一些技巧来设置我的MapView。看这里:

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.fragment_contact, null);

    try {
        MapsInitializer.initialize(this.getActivity().getApplicationContext());
    } catch (GooglePlayServicesNotAvailableException e) {
        e.printStackTrace();
    }

    fragment = new SupportMapFragment() {
        @Override
        public void onActivityCreated(Bundle savedInstanceState) {
            super.onActivityCreated(savedInstanceState);
            mMap = fragment.getMap();
            if (mMap != null) {
                setupMap();
            }
        }
    };

    getFragmentManager().beginTransaction().replace(R.id.fragment_orte_map_parent, fragment).commit();

    return v;
}

当我剪切此MapView时，一切正常。也许有人可以解释我在做什么错。

我完整的Stacktrace:

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.*/com.*.MainActivity}: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.*.FragmentContact$1: make sure class name exists, is public, and has an empty constructor that is public
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2307)
   at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2357)
   at android.app.ActivityThread.access$600(ActivityThread.java:153)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
   at android.os.Handler.dispatchMessage(Handler.java:99)
   at android.os.Looper.loop(Looper.java:137)
   at android.app.ActivityThread.main(ActivityThread.java:5226)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:511)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
   at dalvik.system.NativeStart.main(Native Method)
Caused by: android.support.v4.app.Fragment$InstantiationException: Unable to instantiate fragment com.*.FragmentContact$1: make sure class name exists, is public, and has an empty constructor that is public
   at android.support.v4.app.Fragment.instantiate(Fragment.java:405)
   at android.support.v4.app.FragmentState.instantiate(Fragment.java:97)
   at android.support.v4.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1767)
   at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:208)
   at com.*.MainActivity.onCreate(MainActivity.java:20)
   at android.app.Activity.performCreate(Activity.java:5104)
   at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
   at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2261)
   ... 11 more
Caused by: java.lang.InstantiationException: can't instantiate class com.*.FragmentContact$1; no empty constructor
   at java.lang.Class.newInstanceImpl(Native Method)
   at java.lang.Class.newInstance(Class.java:1319)
   at android.support.v4.app.Fragment.instantiate(Fragment.java:394)
   ... 18 more

最佳答案

该错误不是在提示FragmentContact。它提示FragmentContact(FragmentContact$1)的第一个内部类。您无法将Fragment实现为任何内容的内部类，因为无法从外部类外部对其进行实例化。 static内部类很好。

关于android - fragment -InstantiationException : no empty Constructor -> Google Maps v2?，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/16062923/