Android四种启动模式 生命周期方法调用区别_singletop和standard启动模式下,生命周期回调有何不同

Android 四种启动模式

1. standard
2. singleTop
3. singleTask
4. singleInstance

standard

每次激活Activity时(startActivity)，都创建Activity实例，并放入任务栈

AActivity为standard模式

# 启动AActivity
04-21 15:00:40.687 5013-5013/? D/AActivity: onCreate()
04-21 15:00:40.690 5013-5013/? D/AActivity: onStart()
04-21 15:00:40.690 5013-5013/? D/AActivity: onResume()
# 启动AActivity
04-21 15:00:43.038 5013-5013/com.example.myapplication D/AActivity: onPause()
04-21 15:00:43.047 5013-5013/com.example.myapplication D/AActivity: onCreate()
04-21 15:00:43.048 5013-5013/com.example.myapplication D/AActivity: onStart()
04-21 15:00:43.048 5013-5013/com.example.myapplication D/AActivity: onResume()
04-21 15:00:43.359 5013-5013/com.example.myapplication D/AActivity: onStop()
1
2
3
4
5
6
7
8
9
10

从上面的输出可以看出，前台Activity调用onResume()之后才会调用被覆盖的Activity的onStop()方法

---

singleTop

如果某个Activity自己激活自己，即任务栈栈顶就是该Activity，则不需要创建，其余情况都要创建Activity实例。

AActivity为singleTop模式，BActivity为standard模式

# 启动AActivity
04-21 15:06:54.064 5151-5151/? D/AActivity: onCreate()
04-21 15:06:54.064 5151-5151/? D/AActivity: onStart()
04-21 15:06:54.065 5151-5151/? D/AActivity: onResume()
# 再次启动AActivity
04-21 15:06:59.454 5151-5151/com.example.myapplication D/AActivity: onPause()
04-21 15:06:59.454 5151-5151/com.example.myapplication D/AActivity: onNewIntent()
04-21 15:06:59.454 5151-5151/com.example.myapplication D/AActivity: onResume()
# 启动BActivity
04-21 15:07:09.352 5151-5151/com.example.myapplication D/AActivity: onPause()
04-21 15:07:09.365 5151-5151/com.example.myapplication D/BActivity: onCreate()
04-21 15:07:09.366 5151-5151/com.example.myapplication D/BActivity: onStart()
04-21 15:07:09.366 5151-5151/com.example.myapplication D/BActivity: onResume()
04-21 15:07:09.674 5151-5151/com.example.myapplication D/AActivity: onStop()
# 启动AActivity
04-21 15:07:19.210 5151-5151/com.example.myapplication D/BActivity: onPause()
04-21 15:07:19.220 5151-5151/com.example.myapplication D/AActivity: onCreate()
04-21 15:07:19.221 5151-5151/com.example.myapplication D/AActivity: onStart()
04-21 15:07:19.221 5151-5151/com.example.myapplication D/AActivity: onResume()
04-21 15:07:19.524 5151-5151/com.example.myapplication D/BActivity: onStop()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

---

singleTask

如果要激活的那个Activity在任务栈中存在该实例，则不需要创建，只需要把此Activity放入栈顶，并把该Activity以上的Activity实例都摧毁。

AActivity为singleTask模式，BActivity为standard模式

# 启动AActivity
04-21 15:11:55.777 5334-5334/com.example.myapplication D/AActivity: onCreate()
04-21 15:11:55.778 5334-5334/com.example.myapplication D/AActivity: onStart()
04-21 15:11:55.778 5334-5334/com.example.myapplication D/AActivity: onResume()
# 启动AActivity
04-21 15:12:10.318 5334-5334/com.example.myapplication D/AActivity: onPause()
04-21 15:12:10.318 5334-5334/com.example.myapplication D/AActivity: onNewIntent()
04-21 15:12:10.318 5334-5334/com.example.myapplication D/AActivity: onResume()
# 启动BActivity
04-21 15:12:14.303 5334-5334/com.example.myapplication D/AActivity: onPause()
04-21 15:12:14.316 5334-5334/com.example.myapplication D/BActivity: onCreate()
04-21 15:12:14.316 5334-5334/com.example.myapplication D/BActivity: onStart()
04-21 15:12:14.316 5334-5334/com.example.myapplication D/BActivity: onResume()
04-21 15:12:14.626 5334-5334/com.example.myapplication D/AActivity: onStop()
# 启动BActivity
04-21 15:12:15.522 5334-5334/com.example.myapplication D/BActivity: onPause()
04-21 15:12:15.532 5334-5334/com.example.myapplication D/BActivity: onCreate()
04-21 15:12:15.533 5334-5334/com.example.myapplication D/BActivity: onStart()
04-21 15:12:15.533 5334-5334/com.example.myapplication D/BActivity: onResume()
# 启动AActivity
04-21 15:12:15.826 5334-5334/com.example.myapplication D/BActivity: onStop()
04-21 15:12:16.599 5334-5334/com.example.myapplication D/BActivity: onDestroy()#顶层BActivity被摧毁
04-21 15:12:16.603 5334-5334/com.example.myapplication D/BActivity: onPause()#AActivity的上层BActivity被暂停,没有被立刻摧毁
04-21 15:12:16.612 5334-5334/com.example.myapplication D/AActivity: onNewIntent()
04-21 15:12:16.612 5334-5334/com.example.myapplication D/AActivity: onRestart()
04-21 15:12:16.612 5334-5334/com.example.myapplication D/AActivity: onStart()
04-21 15:12:16.612 5334-5334/com.example.myapplication D/AActivity: onResume()
04-21 15:12:16.825 5334-5334/com.example.myapplication D/BActivity: onStop()
04-21 15:12:16.825 5334-5334/com.example.myapplication D/BActivity: onDestroy()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29

---

singleInstance

如果应用1的任务栈中创建了MainActivity实例，如果应用2也要激活MainActivity，则不需要创建，两应用共享该Activity实例；

AActivity为singleInstance模式，BActivity为standard模式

# 启动AActivity
04-21 15:15:54.413 5475-5475/? D/AActivity: onCreate()
04-21 15:15:54.414 5475-5475/? D/AActivity: onStart()
04-21 15:15:54.414 5475-5475/? D/AActivity: onResume()
# 启动AActivity
04-21 15:15:56.353 5475-5475/com.example.myapplication D/AActivity: onPause()
04-21 15:15:56.353 5475-5475/com.example.myapplication D/AActivity: onNewIntent()
04-21 15:15:56.353 5475-5475/com.example.myapplication D/AActivity: onResume()
# 启动BActivity
04-21 15:15:58.695 5475-5475/com.example.myapplication D/AActivity: onPause()
04-21 15:15:58.702 5475-5475/com.example.myapplication D/BActivity: onCreate()
04-21 15:15:58.703 5475-5475/com.example.myapplication D/BActivity: onStart()
04-21 15:15:58.703 5475-5475/com.example.myapplication D/BActivity: onResume()
04-21 15:15:59.159 5475-5475/com.example.myapplication D/AActivity: onStop()
# 启动BActivity
04-21 15:15:59.987 5475-5475/com.example.myapplication D/BActivity: onPause()
04-21 15:16:00.000 5475-5475/com.example.myapplication D/BActivity: onCreate()
04-21 15:16:00.002 5475-5475/com.example.myapplication D/BActivity: onStart()
04-21 15:16:00.002 5475-5475/com.example.myapplication D/BActivity: onResume()
04-21 15:16:00.308 5475-5475/com.example.myapplication D/BActivity: onStop()
# 启动AActivity
04-21 15:16:01.727 5475-5475/com.example.myapplication D/BActivity: onPause()
04-21 15:16:01.728 5475-5475/com.example.myapplication D/AActivity: onNewIntent()
04-21 15:16:01.728 5475-5475/com.example.myapplication D/AActivity: onRestart()
04-21 15:16:01.729 5475-5475/com.example.myapplication D/AActivity: onStart()
04-21 15:16:01.729 5475-5475/com.example.myapplication D/AActivity: onResume()
04-21 15:16:02.191 5475-5475/com.example.myapplication D/BActivity: onStop()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

---

总结

复用Activity必定会调用onNewIntent，在除standard模式之外的三种模式中栈顶复用的生命周期方法调用都是onPause()、onNewIntent()、onResume()

singleTask复用不是栈顶的Activity时，会调用onNewIntent()、onRestart()、onStart()，而且会清空在要复用的Activity上层的Activity

singleInstance复用不是栈顶的Activity时，同样会调用onNewIntent()、onRestart()、onStart()，但是不会清空在要复用的Activity上层的Activity