android - Main Activity is not garbage collected after destruction because it is referenced by InputMethodManager indirectly -

i followed "avoiding memory leaks" article here.

however proposed solution not solve leak problem. tested android emulator on windows xp (sdk 2.3.1). dumped heap , checked main activity still in heap (i used mat)

here's did:

1. create helloworld app helloworldactivity (it has no child views)
2. run emulator , launch helloworld app.
3. close clicking back-key.
4. cause gc in ddms , dump heap <-- here found helloworldactivity instance.
5. 'path gc roots' shows following path.

helloworldactivity <- phonewindow$decorview <- inputmethodmanager

inputmethodmanager singleton , 3 references decorview references helloworldactivity.

i can't understand why inputmethodmanager still references decorview instance after activity destroyed.

is there way make sure main activity destroyed , gc-able after closing it?

it seems calling inputmethodmanager's methods 'windowdismissed' , 'startgettingwindowfocus' stuff.

something this:

@override protected void ondestroy() {     super.ondestroy();     //fix memory leak: http://code.google.com/p/android/issues/detail?id=34731     fixinputmethodmanager(); }  private void fixinputmethodmanager() {     final object imm = getsystemservice(context.input_method_service);      final reflector.typedobject windowtoken         = new reflector.typedobject(getwindow().getdecorview().getwindowtoken(), ibinder.class);      reflector.invokemethodexceptionsafe(imm, "windowdismissed", windowtoken);      final reflector.typedobject view         = new reflector.typedobject(null, view.class);      reflector.invokemethodexceptionsafe(imm, "startgettingwindowfocus", view); } 

reflector's code:

public static final class typedobject {     private final object object;     private final class type;      public typedobject(final object object, final class type)     {     this.object = object;     this.type = type;     }      object getobject()     {         return object;     }      class gettype()     {         return type;     } }  public static void invokemethodexceptionsafe(final object methodowner, final string method, final typedobject... arguments) {     if (null == methodowner)     {         return;     }      try     {         final class<?>[] types = null == arguments ? new class[0] : new class[arguments.length];         final object[] objects = null == arguments ? new object[0] : new object[arguments.length];          if (null != arguments)         {             (int = 0, limit = types.length; < limit; i++)             {                 types[i] = arguments[i].gettype();                 objects[i] = arguments[i].getobject();             }         }          final method declaredmethod = methodowner.getclass().getdeclaredmethod(method, types);          declaredmethod.setaccessible(true);         declaredmethod.invoke(methodowner, objects);     }     catch (final throwable ignored)     {     } }