探索Activity啟動模式
LifecycleActivity記為A，LifecycleActivity2記為B
一, Standard
略．
二, SingleTop
開啟App，啟動第一個Activity(A1)，看到taskId == 2215
D/PRETTY_LOGGER: │ taskCount == 1 D/PRETTY_LOGGER: │ taskId == 2215 D/PRETTY_LOGGER: │ numActivities == 1 D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity
啟動A2
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2215
D/PRETTY_LOGGER: │ numActivities == 2
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity啟動B(singleTop)
D/PRETTY_LOGGER: │ taskCount == 1 D/PRETTY_LOGGER: │ taskId == 2215 D/PRETTY_LOGGER: │ numActivities == 3 D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity2 D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity
再次啟動B，B沒有創新新例項，而是回調了onNewIntent方法
D/PRETTY_LOGGER: │ Instrumentation.callActivityOnNewIntent (Instrumentation.java:1215)
D/PRETTY_LOGGER: │ LifecycleActivity2.onNewIntent (LifecycleActivity2.kt:48)在B中，啟動A，記為A3
D/PRETTY_LOGGER: │ taskCount == 1 D/PRETTY_LOGGER: │ taskId == 2215 D/PRETTY_LOGGER: │ numActivities == 4 D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity
在A3中，啟動B，例項數增加１，說明不再頂部的B沒有得到複用．
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2215
D/PRETTY_LOGGER: │ numActivities == 5
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity2
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity
總結：singleTop，是棧內複用．
如果某activity為singleTop，
如果它位於棧頂，則回撥onNewIntent()，而不新建例項；
如果不位於棧頂，則新建Activity．
三, SingleTask
開啟App，啟動第一個Activity(A1)，看到taskId == 2212
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2212
D/PRETTY_LOGGER: │ numActivities == 1
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity在A1中，啟動第二個Activity(A2) ，看到taskId不變，activity例項數為２
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2212
D/PRETTY_LOGGER: │ numActivities == 2
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity在A2中，啟動第三個Activity(B)，看到taskId仍不變．activity例項數為３
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2212
D/PRETTY_LOGGER: │ numActivities == 3
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity2
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity在B中，嘗試啟動B，看到B回調了onNewIntent方法
D/PRETTY_LOGGER: │ Instrumentation.callActivityOnNewIntent (Instrumentation.java:1215)
D/PRETTY_LOGGER: │ LifecycleActivity2.onNewIntent (LifecycleActivity2.kt:48)在B中，啟動A，記為A3看到taskId仍不變，activity例項數增加１
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2212
D/PRETTY_LOGGER: │ numActivities == 4
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity在A3中啟動B，此時A3出棧，B出現在棧頂．說明B(singleTask)在棧內複用了，棧內B之上的Activity都出棧．
然後，後續aciivity依次出棧．
總結：singleTask，棧內複用．
如果某Activity為singleTask
如果它位於棧頂，則不建立新例項，它在棧頂被複用；
如果位於棧中，則其上部所有Activity都出棧，該Activity置於棧頂，此為棧內複用．
四, SingleInstance
開啟App，啟動第一個Activity(A1)，看到taskId == 2208
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2208
D/PRETTY_LOGGER: │ numActivities == 1
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity在A1中，啟動第二個Activity(A2) ，看到taskId不變，仍為2208
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2208
D/PRETTY_LOGGER: │ numActivities == 2
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity在A2中，啟動第三個Activity(B)，看到taskId == 2209，已經發生變化
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2209
D/PRETTY_LOGGER: │ numActivities == 1
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity2
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity2我們在B中，再次啟動B，看到B回調了onNewIntent方法，而且numActivities仍為1，說明沒有建立新例項．
D/PRETTY_LOGGER: │ Instrumentation.callActivityOnNewIntent (Instrumentation.java:1215)
D/PRETTY_LOGGER: │ LifecycleActivity2.onNewIntent (LifecycleActivity2.kt:48)然後，在B中，啟動A，看到回到了任務棧A中，activity的例項數增加1，此時的Activity數表示taskId為2208的activity數．
D/PRETTY_LOGGER: │ taskCount == 1
D/PRETTY_LOGGER: │ taskId == 2208
D/PRETTY_LOGGER: │ numActivities == 3
D/PRETTY_LOGGER: │ topActivity == .activity.LifecycleActivity
D/PRETTY_LOGGER: │ baseActivity == .activity.LifecycleActivity然後，點選返回按鈕．發現，taskId(2208)的activity依次出棧，最後task(2209)的activity出棧．（圖略）
總結：singleInstance，建立新的任務棧，而且該Activity獨佔這個任務棧．