final int startActivityLocked(IApplicationThread caller,
            Intent intent, String resolvedType, ActivityInfo aInfo,
            IVoiceInteractionSession voiceSession, IVoiceInteractor voiceInteractor,
            IBinder resultTo, String resultWho, int requestCode,
            int callingPid, int callingUid, String callingPackage,
            int realCallingPid, int realCallingUid, int startFlags, Bundle options,
            boolean componentSpecified, ActivityRecord[] outActivity, ActivityContainer container,
            TaskRecord inTask) {
 
        ActivityRecord r = new ActivityRecord(mService, callerApp, callingUid, callingPackage,
                intent, resolvedType, aInfo, mService.mConfiguration, resultRecord, resultWho,
                requestCode, componentSpecified, this, container, options);
 
 
        err = startActivityUncheckedLocked(r, sourceRecord, voiceSession, voiceInteractor,
                startFlags, true, options, inTask);
}

    ActivityRecord(ActivityManagerService _service, ProcessRecord _caller,
            int _launchedFromUid, String _launchedFromPackage, Intent _intent, String _resolvedType,
            ActivityInfo aInfo, Configuration _configuration,
            ActivityRecord _resultTo, String _resultWho, int _reqCode,
            boolean _componentSpecified, boolean _rootVoiceInteraction,
            ActivityStackSupervisor supervisor,
            ActivityContainer container, Bundle options) {
        service = _service;
        appToken = new Token(this, service);
        info = aInfo;
        launchedFromUid = _launchedFromUid;
        launchedFromPackage = _launchedFromPackage;
        userId = UserHandle.getUserId(aInfo.applicationInfo.uid);
        intent = _intent;
        shortComponentName = _intent.getComponent().flattenToShortString();
        resolvedType = _resolvedType;
        componentSpecified = _componentSpecified;
        rootVoiceInteraction = _rootVoiceInteraction;
        configuration = _configuration;
        stackConfigOverride = (container != null)
                ? container.mStack.mOverrideConfig : Configuration.EMPTY;
        resultTo = _resultTo;
        resultWho = _resultWho;
        requestCode = _reqCode;
        state = ActivityState.INITIALIZING;
    //...

}

   static class Token extends IApplicationToken.Stub {
        private final WeakReference<ActivityRecord> weakActivity;
        private final ActivityManagerService mService;

        Token(ActivityRecord activity, ActivityManagerService service) {
            weakActivity = new WeakReference<>(activity);
            mService = service;
        }
    //...
}    

interface IApplicationToken
{
    void windowsDrawn();
    void windowsVisible();
    void windowsGone();
    boolean keyDispatchingTimedOut(String reason);
    long getKeyDispatchingTimeout();
}

private final void startActivityLocked(......) {
    ......
    mService.mWindowManager.addAppToken(addPos,r.appToken, r.task.taskId,
                               r.info.screenOrientation, r.fullscreen);
    ......
}

public void addAppToken( ) {
            //生成ActivityRecord在WMS中对应的AppWindowToken,并引用到ActivityRecord中的Token,见p2
            atoken = new AppWindowToken(this, token, voiceInteraction); 
            //如果没有Task, 就创建一个task, 并加入到stack中，
            //这里的task/stack都是与AMS中task/stack就一一对应的。 见p3
            Task task = mTaskIdToTask.get(taskId); 

            if (task == null) {
                task = createTaskLocked(taskId, stackId, userId, atoken, taskBounds, config);
            }
            //将AppWindowToken加入到task中管理起来
            task.addAppToken(addPos, atoken, taskResizeMode, homeTask); 
            mTokenMap.put(token.asBinder(), atoken); //加入到mTokenMap中, 见p4
}

AppWindowToken(WindowManagerService _service, IApplicationToken _token,
            boolean _voiceInteraction) {
        //将token的binder对象给AppWindowToken的父类WindowToken引用
        super(_service, _token.asBinder(), 
                WindowManager.LayoutParams.TYPE_APPLICATION, true);
        appWindowToken = this;
        appToken = _token;  //引用到ActivityRecord中的Token
        voiceInteraction = _voiceInteraction;
        mInputApplicationHandle = new InputApplicationHandle(this);
        mAppAnimator = new AppWindowAnimator(this);
    }

wtoken.appToken.windowsDrawn();
wtoken.appToken.windowsVisible(); 
appWindowToken.appToken.keyDispatchingTimedOut(reason);

mTokenMap.put(token.asBinder(), atoken);

attachApplicationLocked
    realStartActivityLocked
        app.thread.scheduleLaunchActivity(new Intent(r.intent), r.appToken, );

public final void scheduleLaunchActivity(Intent intent, IBinder token, ) {
            //生成App中的ActivityClientRecord
            ActivityClientRecord r = new ActivityClientRecord();
            r.token = token;  //将AMS中的token保存到 ActivityClientRecord中 见P5
}

public final class ActivityThread {
   //...
    private ContextImpl mSystemContext;

    static IPackageManager sPackageManager;

    final ApplicationThread mAppThread = new ApplicationThread();
    final Looper mLooper = Looper.myLooper();
    final H mH = new H();
    final ArrayMap<IBinder, ActivityClientRecord> mActivities = new ArrayMap<>();
    // List of new activities (via ActivityRecord.nextIdle) that should
    // be reported when next we idle.
    ActivityClientRecord mNewActivities = null;
    // Number of activities that are currently visible on-screen.
    int mNumVisibleActivities = 0;
    WeakReference<AssistStructure> mLastAssistStructure;
    final ArrayMap<IBinder, Service> mServices = new ArrayMap<>();
  //...
}

//ActivityThread

private void handleLaunchActivity(ActivityClientRecord r, Intent customIntent) {
    //...
    //获取WindowManagerService的Binder引用(proxy端)。
    WindowManagerGlobal.initialize();

    //会调用Activity的onCreate,onStart,onResotreInstanceState方法
    Activity a = performLaunchActivity(r, customIntent);
    if (a != null) {
        //...
        //会调用Activity的onResume方法.
        handleResumeActivity(r.token, false, r.isForward,
                !r.activity.mFinished && !r.startsNotResumed, r.lastProcessedSeq, reason);

        //...
    } 

}

//ActivityThread

   private Activity performLaunchActivity(ActivityClientRecord r, Intent customIntent) {

        //通过类加载器创建Activity
        Activity activity = mInstrumentation.newActivity(cl, component.getClassName(), r.intent);

        //...        

        //通过LoadedApk的makeApplication方法来创建Application对象
        Application app = r.packageInfo.makeApplication(false, mInstrumentation);


        if (activity != null) {
            //...
            activity.attach(appContext, this, getInstrumentation(), r.token,
                    r.ident, app, r.intent, r.activityInfo, title, r.parent,
                    r.embeddedID, r.lastNonConfigurationInstances, config,
                    r.referrer, r.voiceInteractor, window);
            //...

            //onCreate
            mInstrumentation.callActivityOnCreate(activity, r.state);

            //onStart
            activity.performStart();

        }
        return activity;
    }

public interface Callback {

        public boolean dispatchTouchEvent(MotionEvent event);

        public View onCreatePanelView(int featureId);

        public boolean onMenuItemSelected(int featureId, MenuItem item);

        public void onContentChanged();

        public void onWindowFocusChanged(boolean hasFocus);

        public void onAttachedToWindow();

        public void onDetachedFromWindow();
    }

//Activity

final void attach(...) {
        //绑定上下文
        attachBaseContext(context);

        //创建Window,PhoneWindow是Window的唯一具体实现类
        mWindow = new PhoneWindow(this, window);//此处的window==null，但不影响
        mWindow.setWindowControllerCallback(this);
        mWindow.setCallback(this);
        //...
        //设置WindowManager
        mWindow.setWindowManager(
                (WindowManager)context.getSystemService(Context.WINDOW_SERVICE),
                mToken, mComponent.flattenToString(),
                (info.flags & ActivityInfo.FLAG_HARDWARE_ACCELERATED) != 0);
        if (mParent != null) {
            mWindow.setContainer(mParent.getWindow());
        }
        //创建完后通过getWindowManager就可以得到WindowManager实例
        mWindowManager = mWindow.getWindowManager();//其实它是WindowManagerImpl
    }

    @Override
    public Object getSystemService(@ServiceName @NonNull String name) {
        //...
        if (WINDOW_SERVICE.equals(name)) {
            return mWindowManager;
        } 
        return super.getSystemService(name);
    }

//Window


    public void setWindowManager(WindowManager wm, IBinder appToken, String appName,
            boolean hardwareAccelerated) {
        mAppToken = appToken;
        mAppName = appName;
        mHardwareAccelerated = hardwareAccelerated
                || SystemProperties.getBoolean(PROPERTY_HARDWARE_UI, false);
        if (wm == null) {
            wm = (WindowManager)mContext.getSystemService(Context.WINDOW_SERVICE);
        }

        //在此处创建mWindowManager 
        mWindowManager = ((WindowManagerImpl)wm).createLocalWindowManager(this);
    }



//在WindowManagerImpl类中
    public WindowManagerImpl createLocalWindowManager(Window parentWindow) {
        return new WindowManagerImpl(mContext, parentWindow);
    }