Android Framework源码阅读笔记_android framework源码笔记

    TopResumedActivityChangeItem.obtain(onTop));

ClientLifecycleManager.scheduleTransaction{
ClientTransaction clientTransaction = transactionWithCallback(client, activityToken, callback);
{new ClientTransaction(client=ApplicationThread)}
}
clientTransaction.schedule()

### 第二次一个消息: PauseActivityItem

ActivityTaskSupervisor：mAtmService.getLifecycleManager().scheduleTransaction(prev.app.getThread(),
prev.appToken, PauseActivityItem.obtain(prev.finishing, userLeaving,
prev.configChangeFlags, pauseImmediately));

### 第三次 2个 消息：launch and resume

ActivityTaskSupervisor：
final ClientTransaction clientTransaction = ClientTransaction.obtain(
proc.getThread(), r.appToken);
clientTransaction.addCallback(LaunchActivityItem.obtain(new Intent(r.intent),
//还有一个变量：mLifecycleStateRequest:ResumeActivityItem
mService.getLifecycleManager().scheduleTransaction(clientTransaction);

### 第四次一个消息:TopResumedActivityChangeItem

ActivityTaskSupervisor：
ActivityRecord.scheduleTopResumedActivityChanged{
mAtmService.getLifecycleManager().scheduleTransaction(app.getThread(), appToken,
TopResumedActivityChangeItem.obtain(onTop));
}

### 第五个消息 : StopActivityItem

ActivityTaskSupervisor：
ActivityTaskSupervisor.activityIdleInternal>processStoppingAndFinishingActivities>
ActivityRecord.stopPossible{
mAtmService.getLifecycleManager().scheduleTransaction(app.getThread(), appToken,
StopActivityItem.obtain(configChangeFlags));
}

## 重点关注ActivityThread.handleXXX方法：


### handleReLaunchActivity>

performDestroyActivity>
r.activity.retainNonConfigurationInstances();//保存 viewmodel等信息传递到新Activity

### handleLaunchActivity>

unscheduleGcIdler();//取消在后台接受GC的消息
WindowManagerGlobal.initialize();//WMS 初始化
performLaunchActivity>
newActivity//反射创建 activity
makeApplicationif: (mApplication != null) return mApplication;
activity.attach>
attachBaseContext
new PhoneWindow()
if (theme != 0) {
activity. setTheme(theme) ;
}