n条用例验证Activity4种启动模式的威力与坑

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启动模式的使用场景#

标准模式#

特性：

  • 任何页面，如无必要，默认为标准模式，start启动一次创建一个新的Activity

适合场景：

  • 任何页面

singleTop#

特性：

  • 如果该实例已有，且位于栈顶（是Stack顶部还是TaskRecord顶部？），start启动一次，不会重新创建
  • 如果该实例已有，不位于栈顶（是Stack顶部还是TaskRecord顶部？），start启动一次，会重新创建

适合场景：

  • 消息推送： 在单聊页面点击消息通知重新进入一个新的单聊页面
  • 商品推荐：在A商品详情页面点击运营推荐进入一个新的B商品详情页面

singleTask#

特性：

  • 如果该实例已经存在（存在于同一个TaskRecord的？还是存在于Stack中？）但该实例之上还有别的Activity，start启动一次，不会重新创建，会清除该实例之上的所有Activity（清除Stack中其上面的所有？还是TaskRecord内其上面的所有？）

适合场景：

  • 应用中的主页

singleInstance#

特性：

  • 创建一个新的栈结构，似的Activity存在于新的TaskRecord中
  • 如果ActivityA已经存在，通过start方式启动ActivityA，则不会重新创建ActivityA

适合场景：

  • 适用于于App主业务分开的页面
  • 大型App的设置页面
  • 闹铃App，闹铃提醒页面与闹铃设置页面分离

观察Task#

  1. 标准Activity1 -> 标准Activity2
  2. 标准Activity1 -> SingleTask 标记Activity2
  3. 标准Activity1 -> SingleTask +taskAffinity 标记的Activity2
  4. 标准Activity1 -> SingleTop 标记的Activity2
  5. 标准Activity1 -> SingleInstance 标记的Activity2
  6. 标准Activity1 设置启动方式 Intent.FLAG_ACTIVITY_NEW_TASK-> 标准Activity2
  7. 标准Activity1 设置启动方式 allowTaskReparenting -> 标准Activity2

Task小知识#

  • AMS 分配的taskid 是线性递增的，每次开启一个新的task ，taskid 永远都是 +1 的操作。
  • singleTask也是可以做成singleInstance效果的，只要声明taskAffinity 就可以
  • 即一个 task 中的 Activities 是可以运行在不同的进程中的
  • 一个 Activity 运行时所归属的task，默认是启动它 的那个Activity 所在的 task
  • Android 手机的任务列表就是根据不同 task 弹出的，我们可以根据任务管理器有几个 item 图标，来知道我们开启了几个 task
  • 如果 activity 组件没有声明 taskAffinity 的话，该 activity 的 taskAffinity 属性也是有默认值的。
    • 如果 application 指定了 taskAffinity 值，默认值就是 application 指定的 taskAffinity 值；
    • 如果 application 未指定的话，默认值就是 manifest 中声明的包名（package 对应的字符串）。

研究手段#

  1. adb命令查看Activity信息、Task信息、Stack信息，观察Activity顺序、Task顺序、Stack内Activity与Task的顺序
  2. 设计app，至少包括4个Activity，为Activity设置一种启动模式，单独查看每一种启动模式对Activity展示的影响、Task顺序的影响，研究finsh与moveTaskToBack的对比
  3. 总结启动模式的场景

观察SingleTask#

现在我们手里有三个Activity，Activity1 、Activity2、Activity3，启动顺序如下：

Activity1 -> Activity2

Activity2 -> Activity3

Activity1 、Activity2、Activity3分别进行三次配置，观察每一次的启动结果

配置1：

是标准启动模式

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<activity
         android:name=".MainActivity3"
         android:exported="true" />
     <activity
         android:name=".MainActivity2"
         android:exported="true" />
     <activity
         android:name=".MainActivity"
         android:exported="true">
         <intent-filter>
             <action android:name="android.intent.action.MAIN" />
             <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
     </activity>

配置2：

仅配置启动模式

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<activity
    android:name=".MainActivity3"
    android:launchMode="singleTask"
    android:exported="true" />
<activity
    android:name=".MainActivity2"
    android:launchMode="singleTask"
    android:exported="true" />
<activity
    android:name=".MainActivity"
    android:launchMode="singleTask"
    android:exported="true">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

配置3：

启动模式+taskAffinity属性

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<activity
        android:name=".MainActivity3"
        android:launchMode="singleTask"
        android:taskAffinity="com.shaunsheep.ams.singletask.MainActivity3"
        android:exported="true" />
    <activity
        android:name=".MainActivity2"
        android:taskAffinity="com.shaunsheep.ams.singletask.MainActivity2"
        android:launchMode="singleTask"
        android:exported="true" />
    <activity
        android:name=".MainActivity"
        android:taskAffinity="com.shaunsheep.ams.singletask.MainActivity"
        android:launchMode="singleTask"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

第一种配置Activity的launchMode为标准模式

1个TaskRecord，TaskRecord持有3个ActivityRecord，TaskRecord的taskid为#78

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Running activities (most recent first):
  TaskRecord{d10ddfa #78 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
    Run #4: ActivityRecord{9c889db u0 com.shaunsheep.ams/.MainActivity3 t78}
    Run #3: ActivityRecord{8b97fc7 u0 com.shaunsheep.ams/.MainActivity2 t78}
    Run #2: ActivityRecord{d3646df u0 com.shaunsheep.ams/.MainActivity t78}

第二种配置Activity的launchMode为singleTask

1个TaskRecord，TaskRecord持有3个ActivityRecord，TaskRecord的taskid为#77

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Running activities (most recent first):
  TaskRecord{f0344a5 #77 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
    Run #4: ActivityRecord{6df01e3 u0 com.shaunsheep.ams/.MainActivity3 t77}
    Run #3: ActivityRecord{b42be4f u0 com.shaunsheep.ams/.MainActivity2 t77}
    Run #2: ActivityRecord{333cc50 u0 com.shaunsheep.ams/.MainActivity t77}

第三种配置Activity的launchMode为singleTask且配置了taskAffinity

3个TaskRecord，每个TaskRecord持有一个ActivityRecord，每个TaskRecord持有一个新的taskid，共有三个taskid分别是#75 #72 #71

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Running activities (most recent first):
  TaskRecord{4b8cad3 #75 A=com.shaunsheep.ams.singletask.MainActivity3 U=0 StackId=1 sz=1}
    Run #4: ActivityRecord{76a316b u0 com.shaunsheep.ams/.MainActivity3 t75}
  TaskRecord{3e7fa15 #72 A=com.shaunsheep.ams.singletask.MainActivity2 U=0 StackId=1 sz=1}
    Run #3: ActivityRecord{f932d92 u0 com.shaunsheep.ams/.MainActivity2 t72}
  TaskRecord{936112a #71 A=com.shaunsheep.ams.singletask.MainActivity U=0 StackId=1 sz=1}
    Run #2: ActivityRecord{88473fb u0 com.shaunsheep.ams/.MainActivity t71}

为了更清楚的演示Singletask的作用，引入第四种配置，与配置3、配置4比较

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<activity
     android:name=".MainActivity4"
     android:exported="true" />
 <activity
     android:name=".MainActivity3"
     android:launchMode="singleTask"
     android:exported="true" />
 <activity
     android:name=".MainActivity2"
     android:launchMode="singleTask"
     android:exported="true" />
 <activity
     android:name=".MainActivity"
     android:launchMode="singleTask"
     android:exported="true">
     <intent-filter>
         <action android:name="android.intent.action.MAIN" />
         <category android:name="android.intent.category.LAUNCHER" />
     </intent-filter>
 </activity>

从Activity3 -> Activity4 时

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Running activities (most recent first):
      TaskRecord{3fec5b5 #83 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
        Run #4: ActivityRecord{6626c2e u0 com.shaunsheep.ams/.MainActivity4 t83}
        Run #3: ActivityRecord{2423d8a u0 com.shaunsheep.ams/.MainActivity3 t83}
        Run #2: ActivityRecord{a615701 u0 com.shaunsheep.ams/.MainActivity2 t83}
        Run #1: ActivityRecord{746700f u0 com.shaunsheep.ams/.MainActivity t83}

从Activity4 -> Activity2 时

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Running activities (most recent first):
  TaskRecord{3fec5b5 #83 A=com.shaunsheep.ams U=0 StackId=1 sz=2}
    Run #2: ActivityRecord{a615701 u0 com.shaunsheep.ams/.MainActivity2 t83}
    Run #1: ActivityRecord{746700f u0 com.shaunsheep.ams/.MainActivity t83}


由配置3与配置2、配置4相比，可以看到Activity仅配置Launchemode属性为SingleTask,是不会新建TaskRecord的；换言之，只有当标记为SingleTask且 标记一个新的taskAffinity值时，才会创建一个TaskRecord；

由配置4与配置2相比，可以看到Activity仅仅配置SingleTask，可以达到的效果是：当一个标记为SingleTask的Activity2被重新启动后，该TaskRecord里面位于Activity2之上的ActivityRecord会被清除；

当没有配置taskAffinity，SingleTask标记的Activity仅拥有清除特性；

当配置taskAffinity，SingleTask标记的Activity才会处于一个新的TaskRecord

引入配置5

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<activity
        android:name=".MainActivity4"
        android:exported="true" />
    <activity
        android:name=".MainActivity3"
        android:launchMode="singleTask"
        android:taskAffinity="com.shaunsheep.ams.singletask.MainActivity3"
        android:exported="true" />
    <activity
        android:name=".MainActivity2"
        android:taskAffinity="com.shaunsheep.ams.singletask.MainActivity2"
        android:launchMode="singleTask"
        android:exported="true" />
    <activity
        android:name=".MainActivity"
        android:exported="true">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

从Activity3 -> Activity4 时

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Running activities (most recent first):
   TaskRecord{7b3783a #86 A=com.shaunsheep.ams.singletask.MainActivity3 U=0 StackId=1 sz=2}
     Run #4: ActivityRecord{57405d2 u0 com.shaunsheep.ams/.MainActivity4 t86}
     Run #3: ActivityRecord{c785935 u0 com.shaunsheep.ams/.MainActivity3 t86}
   TaskRecord{ce80ceb #85 A=com.shaunsheep.ams.singletask.MainActivity2 U=0 StackId=1 sz=1}
     Run #2: ActivityRecord{a21fe37 u0 com.shaunsheep.ams/.MainActivity2 t85}
   TaskRecord{b7f4a48 #84 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
     Run #1: ActivityRecord{a172b4f u0 com.shaunsheep.ams/.MainActivity t84}
   TaskRecord{9e28cc #62 A=com.unilife.fridge.haierbase.tft U=0 StackId=1 sz=1}
     Run #0: ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}


从Activity4 -> Activity2 时

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Running activities (most recent first):
  TaskRecord{ce80ceb #85 A=com.shaunsheep.ams.singletask.MainActivity2 U=0 StackId=1 sz=1}
    Run #4: ActivityRecord{a21fe37 u0 com.shaunsheep.ams/.MainActivity2 t85}
  TaskRecord{7b3783a #86 A=com.shaunsheep.ams.singletask.MainActivity3 U=0 StackId=1 sz=2}
    Run #3: ActivityRecord{57405d2 u0 com.shaunsheep.ams/.MainActivity4 t86}
    Run #2: ActivityRecord{c785935 u0 com.shaunsheep.ams/.MainActivity3 t86}
  TaskRecord{b7f4a48 #84 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #1: ActivityRecord{a172b4f u0 com.shaunsheep.ams/.MainActivity t84}
  TaskRecord{9e28cc #62 A=com.unilife.fridge.haierbase.tft U=0 StackId=1 sz=1}
    Run #0: ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}


可以看到，当Activity、Activity2、Activity3分别创建了三个TaskRecord时，Activity3启动的Activity4，两者都在TaskId为#85的TaskRecord里。

当Activity4启动标记为SingleTask的Activity2时，Activity2所在的#85 Task上移到Stack顶。

启发，SingleInstance、SingleTop的TaskRecord、ActivityRecord分布关系是怎样的呢？

观察SingleTop#

配置1：引入4个标记为SingleTop的Activity

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<activity
          android:name=".singletop.MainActivity4"
          android:launchMode="singleTop"
          android:exported="true" />
      <activity
          android:name=".singletop.MainActivity3"
          android:launchMode="singleTop"
          android:exported="true" />
      <activity
          android:name=".singletop.MainActivity2"
          android:launchMode="singleTop"
          android:exported="true" />
      <activity
          android:name=".singletop.MainActivity"
          android:launchMode="singleTop"
          android:exported="true" />

栈顶启动一个处于非栈顶的标记为SingleTop 且未创建的Activity

Activity3 -> Activity4时

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Running activities (most recent first):
   TaskRecord{a809353 #94 A=com.shaunsheep.ams U=0 StackId=1 sz=5}
     Run #5: ActivityRecord{fa4458e u0 com.shaunsheep.ams/.singletop.MainActivity4 t94}
     Run #4: ActivityRecord{e960865 u0 com.shaunsheep.ams/.singletop.MainActivity3 t94}
     Run #3: ActivityRecord{6a2a418 u0 com.shaunsheep.ams/.singletop.MainActivity2 t94}
     Run #2: ActivityRecord{6387394 u0 com.shaunsheep.ams/.singletop.MainActivity t94}
     Run #1: ActivityRecord{a909021 u0 com.shaunsheep.ams/.LaunchActivity t94}


测试1：从Activity4 -> Activity2 时，Activity2处于非栈顶且已经被创建，TaskRecord会装入一个新的Activity2，此时#94有两个Activity2

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Running activities (most recent first):
  TaskRecord{a809353 #94 A=com.shaunsheep.ams U=0 StackId=1 sz=6}
    Run #6: ActivityRecord{32759ec u0 com.shaunsheep.ams/.singletop.MainActivity2 t94}
    Run #5: ActivityRecord{fa4458e u0 com.shaunsheep.ams/.singletop.MainActivity4 t94}
    Run #4: ActivityRecord{e960865 u0 com.shaunsheep.ams/.singletop.MainActivity3 t94}
    Run #3: ActivityRecord{6a2a418 u0 com.shaunsheep.ams/.singletop.MainActivity2 t94}
    Run #2: ActivityRecord{6387394 u0 com.shaunsheep.ams/.singletop.MainActivity t94}
    Run #1: ActivityRecord{a909021 u0 com.shaunsheep.ams/.LaunchActivity t94}

测试2：栈顶启动一个处于栈顶的标记为SingleTop的Activity，

Activity3 -> Activity4时

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Running activities (most recent first):
  TaskRecord{4cac736 #104 A=com.shaunsheep.ams U=0 StackId=1 sz=5}
    Run #5: ActivityRecord{b712b49 u0 com.shaunsheep.ams/.singletop.MainActivity4 t104}
    Run #4: ActivityRecord{8a27a95 u0 com.shaunsheep.ams/.singletop.MainActivity3 t104}
    Run #3: ActivityRecord{87017a1 u0 com.shaunsheep.ams/.singletop.MainActivity2 t104}
    Run #2: ActivityRecord{67f2e6d u0 com.shaunsheep.ams/.singletop.MainActivity t104}
    Run #1: ActivityRecord{1cc8763 u0 com.shaunsheep.ams/.LaunchActivity t104}

从Activity4 -> Activity4 时，Activity4已经被创建过，再次启动，因此TaskRecord会重新加载Activity3，并进入onNewIntent方法

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Running activities (most recent first):
  TaskRecord{4cac736 #104 A=com.shaunsheep.ams U=0 StackId=1 sz=5}
    Run #5: ActivityRecord{b712b49 u0 com.shaunsheep.ams/.singletop.MainActivity4 t104}
    Run #4: ActivityRecord{8a27a95 u0 com.shaunsheep.ams/.singletop.MainActivity3 t104}
    Run #3: ActivityRecord{87017a1 u0 com.shaunsheep.ams/.singletop.MainActivity2 t104}
    Run #2: ActivityRecord{67f2e6d u0 com.shaunsheep.ams/.singletop.MainActivity t104}
    Run #1: ActivityRecord{1cc8763 u0 com.shaunsheep.ams/.LaunchActivity t104}

并且Activity4的log得到了打印

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2021-10-09 14:45:43.849 12224-12224/com.shaunsheep.ams E/ycf: onNewIntent

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    Log.e("ycf","onNewIntent");
}

总结SingleTop的小知识：

  • 由测试1可知，当启动一个未处于栈顶标记为SingleTop的Activity2时，Activity2会重新创建一遍，此时TaskRecord中存在两个Activity2
  • 由测试2可知，当启动一个处于栈顶的标记为SingleTop的Activity4时，Activity4并不会重新创建，而是进入该Activity的onNewIntent方法
  • 由测试1、测试2可知，SingleTop并不会新创建一个TaskRecord，仍然处于创建它的Activity所处的TaskRecord内

观察SingleInstance#

配置1：4个SingleInstance#

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<activity
    android:name=".singleinstance.MainActivity4"
    android:launchMode="singleInstance"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity3"
    android:launchMode="singleInstance"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity2"
    android:launchMode="singleInstance"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity"
    android:launchMode="singleInstance"
    android:exported="true" />

Activity3 -> Activity4时

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Running activities (most recent first):
  TaskRecord{ceec50d #110 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #9: ActivityRecord{380cf0a u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t110}
  TaskRecord{70c2b67 #109 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #8: ActivityRecord{c7b8b53 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t109}
  TaskRecord{3c97bb2 #108 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{1fd4065 u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t108}
  TaskRecord{e261703 #107 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #6: ActivityRecord{e1b93e7 u0 com.shaunsheep.ams/.singleinstance.MainActivity t107}

Activity4 -> Activity2时

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Running activities (most recent first):
  TaskRecord{3c97bb2 #108 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #9: ActivityRecord{1fd4065 u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t108}
  TaskRecord{ceec50d #110 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #8: ActivityRecord{380cf0a u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t110}
  TaskRecord{70c2b67 #109 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{c7b8b53 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t109}
  TaskRecord{e261703 #107 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #6: ActivityRecord{e1b93e7 u0 com.shaunsheep.ams/.singleinstance.MainActivity t107}
  TaskRecord{8ce680 #106 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #5: ActivityRecord{8277ba3 u0 com.shaunsheep.ams/.LaunchActivity t106}

Activity4 -> Activity4时

执行了log

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2021-10-09 16:25:30.499 32395-32395/com.shaunsheep.ams E/ycf: onNewIntent

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Running activities (most recent first):
  TaskRecord{ceec50d #110 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #9: ActivityRecord{380cf0a u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t110}
  TaskRecord{70c2b67 #109 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #8: ActivityRecord{c7b8b53 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t109}
  TaskRecord{3c97bb2 #108 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{1fd4065 u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t108}
  TaskRecord{e261703 #107 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #6: ActivityRecord{e1b93e7 u0 com.shaunsheep.ams/.singleinstance.MainActivity t107}
  TaskRecord{8ce680 #106 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #5: ActivityRecord{8277ba3 u0 com.shaunsheep.ams/.LaunchActivity t106}

可以看到，当所有Activity都配置成SingleInstance 时候，

Activity4 在栈顶启动自己，Activity4没有重新创建

Activity4 在栈顶启动了Activity2，Activity2 没有重新创建，Activity2 重新置于栈顶

配置2：1个SingleInstance#

Activity2为singleInstance

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<activity
    android:name=".singleinstance.MainActivity4"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity3"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity2"
    android:launchMode="singleInstance"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity"
    android:exported="true" />

测试0：栈列表

一共有两个TaskRecord，标记启动模式为SingleIntance的Activity2位于Task#135中，Activity1、3、4位于Task#134中

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Running activities (most recent first):
  TaskRecord{9609526 #134 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
    Run #9: ActivityRecord{4fbc425 u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t134}
    Run #8: ActivityRecord{2dffdbb u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t134}
  TaskRecord{43e1f14 #135 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{bceb142 u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t135}
  TaskRecord{9609526 #134 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
    Run #6: ActivityRecord{4215219 u0 com.shaunsheep.ams/.singleinstance.MainActivity t134}
    Run #5: ActivityRecord{5f3ff00 u0 com.shaunsheep.ams/.LaunchActivity t134}

测试1：启动App，Activity4 -> Activity2时

打印了log

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2021-10-09 16:39:16.192 4704-4704/com.shaunsheep.ams E/ycf: MainActivity2 onNewIntent

栈列表有两个#135 和#134，#135有Activity2，#134有Activity4、Activity3、Activity1、LaunchActivity

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Running activities (most recent first):
  TaskRecord{43e1f14 #135 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #9: ActivityRecord{bceb142 u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t135}
  TaskRecord{9609526 #134 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
    Run #8: ActivityRecord{4fbc425 u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t134}
    Run #7: ActivityRecord{2dffdbb u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t134}
    Run #6: ActivityRecord{4215219 u0 com.shaunsheep.ams/.singleinstance.MainActivity t134}
    Run #5: ActivityRecord{5f3ff00 u0 com.shaunsheep.ams/.LaunchActivity t134}

测试2：重启App，Activity2->Activity3时

有两个Task #136和 #137，#136有Activity1、LaunchActivity和Activity3，#137有Activity2

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Running activities (most recent first):
  TaskRecord{e558bba #136 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
    Run #8: ActivityRecord{9fea423 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t136}
  TaskRecord{ab449c8 #137 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{4cbaab5 u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t137}
  TaskRecord{e558bba #136 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
    Run #6: ActivityRecord{45c62a8 u0 com.shaunsheep.ams/.singleinstance.MainActivity t136}
    Run #5: ActivityRecord{e23987e u0 com.shaunsheep.ams/.LaunchActivity t136}

测试3：重新启动App，Activity2->Activity3时，重新刷新一遍栈列表，方便下一轮测试，此时TaskId会自增，不再是原来的#137 和#136，而是#138 和#139

在Activity3按下moveTaskToBack(true);，跳回了Activity2

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Running activities (most recent first):
  TaskRecord{717c0c5 #139 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #8: ActivityRecord{1aaf98b u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t139}
  TaskRecord{df04ae3 #138 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
    Run #7: ActivityRecord{d5687b0 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t138}
    Run #6: ActivityRecord{7423876 u0 com.shaunsheep.ams/.singleinstance.MainActivity t138}
    Run #5: ActivityRecord{6bbfbbb u0 com.shaunsheep.ams/.LaunchActivity t138}

此时再次Activity2->Activity3时，重新创建Activity3，注意此时# 138有两个Activity3

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Running activities (most recent first):
  TaskRecord{df04ae3 #138 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
    Run #9: ActivityRecord{5e4f6c3 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t138}
  TaskRecord{717c0c5 #139 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #8: ActivityRecord{1aaf98b u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t139}
  TaskRecord{df04ae3 #138 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
    Run #7: ActivityRecord{d5687b0 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t138}
    Run #6: ActivityRecord{7423876 u0 com.shaunsheep.ams/.singleinstance.MainActivity t138}
    Run #5: ActivityRecord{6bbfbbb u0 com.shaunsheep.ams/.LaunchActivity t138}

在第二个Activity3按下finsh或者backPress，直接跳回了第一个Activity3，而非预期的Activity2

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Running activities (most recent first):
  TaskRecord{df04ae3 #138 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
    Run #8: ActivityRecord{d5687b0 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t138}
  TaskRecord{717c0c5 #139 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{1aaf98b u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t139}
  TaskRecord{df04ae3 #138 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
    Run #6: ActivityRecord{7423876 u0 com.shaunsheep.ams/.singleinstance.MainActivity t138}
    Run #5: ActivityRecord{6bbfbbb u0 com.shaunsheep.ams/.LaunchActivity t138}

在第一个Activity3按下finsh或者backPress，直接跳回了Activity1，而非预期的Activity2

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Running activities (most recent first):
  TaskRecord{df04ae3 #138 A=com.shaunsheep.ams U=0 StackId=1 sz=2}
    Run #7: ActivityRecord{7423876 u0 com.shaunsheep.ams/.singleinstance.MainActivity t138}
  TaskRecord{717c0c5 #139 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #6: ActivityRecord{1aaf98b u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t139}
  TaskRecord{df04ae3 #138 A=com.shaunsheep.ams U=0 StackId=1 sz=2}
    Run #5: ActivityRecord{6bbfbbb u0 com.shaunsheep.ams/.LaunchActivity t138}

总结SingleInstance的小知识：

  • 由测试0可知，SingleInstance标记的Activity2，必然会独立存在于一个TaskRecord中，它自己启动的新的Activity3，会存在于默认的Task中，默认的Task是启动Activity2的Activity1所在的TaskRecord

  • 由测试1可知，SingleInstance所标记的Activity，如果是首次创建，一定会新创建一个TaskRecord，并置于其中；已经创建，则会使得TaskRecord置于Stack顶部

  • 由测试2和测试3可知标准Activity 1 -> SingleInstance Activity2 -> 标准Activity 3 ，在Activity3 finsh或backPress会跳入Activity1；在Activity3触发moveTaskToBack会跳入Activity2

  • 根据网络文章如果位于Activity2，按下手机home键，重新进入App后，会显示Activity1，可知SingleInstance标记的Activity也影响home键之后的页面展示

  • 由以上三点，可知SingleInstance标记的Activity会影响finsh、backPress、home三类操作之后的页面展示顺序；

进阶测试——activity回退的小bug：#

继续使用配置2：

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<activity
    android:name=".singleinstance.MainActivity4"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity3"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity2"
    android:launchMode="singleInstance"
    android:exported="true" />
<activity
    android:name=".singleinstance.MainActivity"
    android:exported="true" />

AMS体系-奇怪的现象

? 在下文中，将moveTaskToBack简写moveback

几个关键的步骤流

①

1…4的TaskRecord结果如下：，Task#611 存放Activity1、3、4， Task#612存放Activity2，Task#611在栈顶，此时屏幕上展示的是Activity4，符合TaskRecord中的顺序

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Running activities (most recent first):
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
    Run #5: ActivityRecord{7517f4d u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #4: ActivityRecord{d1ea723 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
  TaskRecord{bf2d0e0 #612 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #3: ActivityRecord{15e944a u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t612}
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
    Run #2: ActivityRecord{fe3edcb u0 com.shaunsheep.ams/.singleinstance.MainActivity t611}
    Run #1: ActivityRecord{83513cf u0 com.shaunsheep.ams/.LaunchActivity t611}


②

4..moveback的结果如下：

Task#611 存放Activity1、3、4， Task#612存放Activity2，Task#612在栈顶，此时屏幕上展示的是Activity2，符合TaskRecord中的顺序

思考1Tips：此处产生一个小问题，结果不符合我们期望的顺序——程序只moveback了Activity4，没有moveBack Activity3，为什么moveBack Activity4之后，看不到Activity3而是看到Activity2呢？

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Running activities (most recent first):
    TaskRecord{bf2d0e0 #612 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
      Run #5: ActivityRecord{15e944a u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t612}
    TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=4}
      Run #4: ActivityRecord{7517f4d u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
      Run #3: ActivityRecord{d1ea723 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
      Run #2: ActivityRecord{fe3edcb u0 com.shaunsheep.ams/.singleinstance.MainActivity t611}
      Run #1: ActivityRecord{83513cf u0 com.shaunsheep.ams/.LaunchActivity t611}


③

2..4的结果如下：

Task#611 存放Activity1、3、4、3、4， Task#612存放Activity2，Task#611在栈顶，此时屏幕上展示的是Activity4，符合TaskRecord中的顺序

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Running activities (most recent first):
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=6}
    Run #7: ActivityRecord{4798b46 u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #6: ActivityRecord{4e20f6c u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
  TaskRecord{bf2d0e0 #612 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #5: ActivityRecord{15e944a u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t612}
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=6}
    Run #4: ActivityRecord{7517f4d u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #3: ActivityRecord{d1ea723 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
    Run #2: ActivityRecord{fe3edcb u0 com.shaunsheep.ams/.singleinstance.MainActivity t611}
    Run #1: ActivityRecord{83513cf u0 com.shaunsheep.ams/.LaunchActivity t611}


④

4…moveBack-2结果如下：与步骤2相比，仅多了1个Activity4、1个Activity3，伴随着思考1，moveBack的特性越发引人关注了

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Running activities (most recent first):
  TaskRecord{bf2d0e0 #612 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{15e944a u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t612}
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=6}
    Run #6: ActivityRecord{4798b46 u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #5: ActivityRecord{4e20f6c u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
    Run #4: ActivityRecord{7517f4d u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #3: ActivityRecord{d1ea723 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
    Run #2: ActivityRecord{fe3edcb u0 com.shaunsheep.ams/.singleinstance.MainActivity t611}
    Run #1: ActivityRecord{83513cf u0 com.shaunsheep.ams/.LaunchActivity t611}


⑤

2…3结果如下：

可以看到Task#611有Activity1、3、4、3、4、3，Task#612有Activity2，此时屏幕上看到的是Activity3，符合TaskRecord的顺序

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Running activities (most recent first):
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=7}
    Run #8: ActivityRecord{7702d48 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
  TaskRecord{bf2d0e0 #612 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #7: ActivityRecord{15e944a u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t612}
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=7}
    Run #6: ActivityRecord{4798b46 u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #5: ActivityRecord{4e20f6c u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
    Run #4: ActivityRecord{7517f4d u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #3: ActivityRecord{d1ea723 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
    Run #2: ActivityRecord{fe3edcb u0 com.shaunsheep.ams/.singleinstance.MainActivity t611}
    Run #1: ActivityRecord{83513cf u0 com.shaunsheep.ams/.LaunchActivity t611}


⑥

在步骤6我们暂停一下，梳理一下逻辑，在这里我们假定实际开发中有一个需求，退出Activity3，显示启动它的Activity2。我们可以通过哪些方式来实现？最简洁的方式就是finsh 销毁Activity3，那我们来实际操作一下看看结果：

finsh 3结果如下：

可以看到Task#611有Activity1、3、4、3、4，Task#612有Activity2，此时屏幕上看到的是Activity4，非常令人震惊，明明在展示Activity3之前，我们看到的Activity2，为什么Activity3销毁，我们看不到Activity2呢？当然下面的TaskRecord已经给出答案，Activity3销毁之后，默认将与Activity3同一TaskRecord的Activity4顶了上来，这也符合TaskRecord列表显示的数据：

Activity3销毁之后看到的是同一TaskRecord的Activity4 而不是启动Activity3的Activity2

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Running activities (most recent first):
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=6}
    Run #7: ActivityRecord{4798b46 u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
  TaskRecord{bf2d0e0 #612 A=com.shaunsheep.ams U=0 StackId=1 sz=1}
    Run #6: ActivityRecord{15e944a u0 com.shaunsheep.ams/.singleinstance.MainActivity2 t612}
  TaskRecord{f170712 #611 A=com.shaunsheep.ams U=0 StackId=1 sz=6}
    Run #5: ActivityRecord{4e20f6c u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
    Run #4: ActivityRecord{7517f4d u0 com.shaunsheep.ams/.singleinstance.MainActivity4 t611}
    Run #3: ActivityRecord{d1ea723 u0 com.shaunsheep.ams/.singleinstance.MainActivity3 t611}
    Run #2: ActivityRecord{fe3edcb u0 com.shaunsheep.ams/.singleinstance.MainActivity t611}
    Run #1: ActivityRecord{83513cf u0 com.shaunsheep.ams/.LaunchActivity t611}


位于栈顶的Activity3如果通过moveTaskToBack方式回退，则可以实现Activity3消失、显示Activity2的效果

以上问题引发了思考：

  • startActivity、finsh、moveTaskToBack三者之间有何联系

  • finsh与moveTaskToBack对Activity显示有何区别

finsh与moveTaskToBack的对比：

操作上：

  • 两者都会操作WindowList<E> mChildren中子元素顺序
  • moveToBack是一个移动数组末尾元素至首位的操作
  • finsh是一个移除数组末尾元素的操作

显示上：

  • 两者最终呈现在界面上的效果，都是将当前顶部Activity隐藏
  • 两者最明显的区别是，隐藏顶部Activity之后，操作之后，屏幕锁显示的下一个Activity的区别
    • moveTaskToBack会隐藏当前Activity所在的TaskRecord，展示Stack中的下一个TaskRecord
    • finsh会销毁当前Activity，并展示当前Activity所在的TaskReord中的下一个Activity，而非实际的Stack存储的ActivityRecord顺序

帮助文档#

adb#

查看Window#

adb shell "dumpsys window"

主要关注

  • WINDOW MANAGER ANIMATOR STATE
  • WINDOW MANAGER SESSIONS (dumpsys window sessions)
  • WINDOW MANAGER DISPLAY CONTENTS (dumpsys window displays)
  • WINDOW MANAGER TOKENS (dumpsys window tokens)

截取部分段落

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WINDOW MANAGER ANIMATOR STATE (dumpsys window animator)
    DisplayContentsAnimator #0:
      Window #0: WindowStateAnimator{8300f9b com.android.systemui.ImageWallpaper}
      Window #1: WindowStateAnimator{e1a0f38 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity}
      Window #2: WindowStateAnimator{f0bbb11 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity}
      Window #3: WindowStateAnimator{b240476 com.shaunsheep.ams/com.shaunsheep.ams.singletask.MainActivity}
      Window #4: WindowStateAnimator{f60a77 com.shaunsheep.ams/com.shaunsheep.ams.singletask.MainActivity2}
      Window #5: WindowStateAnimator{efce6e4 com.shaunsheep.ams/com.shaunsheep.ams.singletask.MainActivity3}
      Window #6: WindowStateAnimator{85ff74d DockedStackDivider}
      Window #7: WindowStateAnimator{c3f202 }
      Window #8: WindowStateAnimator{6b6d713 AssistPreviewPanel}
      Window #9: WindowStateAnimator{d138d50 StatusBar}


    mBulkUpdateParams=0x8 ORIENTATION_CHANGE_COMPLETE

WINDOW MANAGER SESSIONS (dumpsys window sessions)
  Session Session{567f3f 9459:u0a10057}:
    mNumWindow=3 mCanAddInternalSystemWindow=false mAppOverlaySurfaces=[] mAlertWindowSurfaces=[] mClientDead=false mSurfaceSession=android.view.SurfaceSession@241bb49
    mPackageName=com.shaunsheep.ams
  Session Session{15833c4 622:1000}:
    mNumWindow=0 mCanAddInternalSystemWindow=true mAppOverlaySurfaces=[] mAlertWindowSurfaces=[] mClientDead=false mSurfaceSession=android.view.SurfaceSession@832c4e
    mPackageName=com.shaunsheep.ams
  Session Session{337aec5 2545:1000}:
    mNumWindow=0 mCanAddInternalSystemWindow=true mAppOverlaySurfaces=[] mAlertWindowSurfaces=[] mClientDead=false mSurfaceSession=android.view.SurfaceSession@1add16f
    mPackageName=com.unilife.fridge.haierbase.navigation
  Session Session{6c2c045 1075:1000}:
    mNumWindow=0 mCanAddInternalSystemWindow=true mAppOverlaySurfaces=[] mAlertWindowSurfaces=[] mClientDead=false mSurfaceSession=android.view.SurfaceSession@7ac2e7c
    mPackageName=com.android.settings
  Session Session{851ad14 1300:1000}:
    mNumWindow=1 mCanAddInternalSystemWindow=true mAppOverlaySurfaces=[] mAlertWindowSurfaces=[] mClientDead=false mSurfaceSession=android.view.SurfaceSession@a61c305
    mPackageName=com.example.touchdemo
  Session Session{8bd8947 1341:u0a10033}:
    mNumWindow=2 mCanAddInternalSystemWindow=false mAppOverlaySurfaces=[] mAlertWindowSurfaces=[] mClientDead=false mSurfaceSession=android.view.SurfaceSession@fe9bf5a
    mPackageName=com.unilife.fridge.haierbase.tft
  Session Session{b4457ef 796:u0a10010}:
    mNumWindow=4 mCanAddInternalSystemWindow=true mAppOverlaySurfaces=[] mAlertWindowSurfaces=[] mClientDead=false mSurfaceSession=android.view.SurfaceSession@870158b
    mPackageName=com.android.systemui

WINDOW MANAGER DISPLAY CONTENTS (dumpsys window displays)
  Display: mDisplayId=0
    init=1080x1920 160dpi cur=1080x1920 app=1080x1864 rng=1080x1024-1920x1864
    deferred=false mLayoutNeeded=false mTouchExcludeRegion=SkRegion((0,0,1080,1920))

  Application tokens in top down Z order:
    mStackId=1
    mDeferRemoval=false
    mFillsParent=true
    mBounds=[0,0][1080,1920]
      taskId=63
        mFillsParent=true
        mBounds=[0,0][1080,1920]
        mdr=false
        appTokens=[AppWindowToken{4df35c8 token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}}, AppWindowToken{9051be2 token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}}, AppWindowToken{6e77b06 to
ken=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}}]
        mTempInsetBounds=[0,0][0,0]
          Activity #2 AppWindowToken{6e77b06 token=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}}
          windows=[Window{8f48b1d u0 com.shaunsheep.ams/com.shaunsheep.ams.singletask.MainActivity3}]
          windowType=2 hidden=false hasVisible=true
          app=true mVoiceInteraction=false
          task={taskId=63 appTokens=[AppWindowToken{4df35c8 token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}}, AppWindowToken{9051be2 token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}}, AppWind
owToken{6e77b06 token=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}}] mdr=false}
           mFillsParent=true mOrientation=-1
          hiddenRequested=false mClientHidden=false reportedDrawn=true reportedVisible=true
          mAppStopped=true
          mNumInterestingWindows=1 mNumDrawnWindows=1 inPendingTransaction=false allDrawn=true (animator=true)
          startingData=null removed=false firstWindowDrawn=true mIsExiting=false
          controller=AppWindowContainerController{ token=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}} mContainer=AppWindowToken{6e77b06 token=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}} mListen
er=ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}
          Activity #1 AppWindowToken{9051be2 token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}}
          windows=[Window{574d6a9 u0 com.shaunsheep.ams/com.shaunsheep.ams.singletask.MainActivity2}]
          windowType=2 hidden=true hasVisible=true
          app=true mVoiceInteraction=false
          task={taskId=63 appTokens=[AppWindowToken{4df35c8 token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}}, AppWindowToken{9051be2 token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}}, AppWind
owToken{6e77b06 token=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}}] mdr=false}
           mFillsParent=true mOrientation=-1
          hiddenRequested=true mClientHidden=true reportedDrawn=false reportedVisible=false
          mAppStopped=true
          mNumInterestingWindows=1 mNumDrawnWindows=1 inPendingTransaction=false allDrawn=true (animator=true)
          startingData=null removed=false firstWindowDrawn=true mIsExiting=false
          controller=AppWindowContainerController{ token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}} mContainer=AppWindowToken{9051be2 token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}} mListen
er=ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}
          Activity #0 AppWindowToken{4df35c8 token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}}
          windows=[Window{b61636a u0 com.shaunsheep.ams/com.shaunsheep.ams.singletask.MainActivity}]
          windowType=2 hidden=true hasVisible=true
          app=true mVoiceInteraction=false
          task={taskId=63 appTokens=[AppWindowToken{4df35c8 token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}}, AppWindowToken{9051be2 token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}}, AppWind
owToken{6e77b06 token=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}}] mdr=false}
           mFillsParent=true mOrientation=-1
          hiddenRequested=true mClientHidden=true reportedDrawn=false reportedVisible=false
          mAppStopped=true
          mNumInterestingWindows=1 mNumDrawnWindows=1 inPendingTransaction=false allDrawn=true (animator=true)
          startingData=null removed=false firstWindowDrawn=true mIsExiting=false
          controller=AppWindowContainerController{ token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}} mContainer=AppWindowToken{4df35c8 token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}} mListener
=ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}
      taskId=62
        mFillsParent=true
        mBounds=[0,0][1080,1920]
        mdr=false
        appTokens=[AppWindowToken{f92e433 token=Token{a4766b5 ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}}}, AppWindowToken{e23349e token=Token{bd672d9 ActivityRecord{5129
20 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}}}]
        mTempInsetBounds=[0,0][0,0]
          Activity #1 AppWindowToken{e23349e token=Token{bd672d9 ActivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}}}
          windows=[Window{e22a411 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity}]
          windowType=2 hidden=true hasVisible=true
          app=true mVoiceInteraction=false
          task={taskId=62 appTokens=[AppWindowToken{f92e433 token=Token{a4766b5 ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}}}, AppWindowToken{e23349e token=Token{bd672d9 A
ctivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}}}] mdr=false}
           mFillsParent=true mOrientation=-1
          hiddenRequested=true mClientHidden=true reportedDrawn=false reportedVisible=false
          mAppStopped=true
          mNumInterestingWindows=1 mNumDrawnWindows=1 inPendingTransaction=false allDrawn=true (animator=true)
          startingData=null removed=false firstWindowDrawn=true mIsExiting=false
          controller=AppWindowContainerController{ token=Token{bd672d9 ActivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}} mContainer=AppWindowToken{e23349e token=Token{bd672d9 Ac
tivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}}} mListener=ActivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSe
tWifiActivity t62}}
          Activity #0 AppWindowToken{f92e433 token=Token{a4766b5 ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}}}
          windows=[Window{ba965b4 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity}]
          windowType=2 hidden=true hasVisible=true
          app=true mVoiceInteraction=false
          task={taskId=62 appTokens=[AppWindowToken{f92e433 token=Token{a4766b5 ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}}}, AppWindowToken{e23349e token=Token{bd672d9 A
ctivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}}}] mdr=false}
           mFillsParent=true mOrientation=-1
          hiddenRequested=true mClientHidden=true reportedDrawn=false reportedVisible=false
          mAppStopped=true
          mNumInterestingWindows=1 mNumDrawnWindows=1 inPendingTransaction=false allDrawn=true (animator=true)
          startingData=null removed=false firstWindowDrawn=true mIsExiting=false
          controller=AppWindowContainerController{ token=Token{a4766b5 ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}} mContainer=AppWindowToken{f92e433 token=Token{a4766b5 A
ctivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}}} mListener=ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUser
ProtocolActivity t62}}
    mStackId=0
    mDeferRemoval=false
    mFillsParent=true
    mBounds=[0,0][1080,1920]


  DimLayerController
    Task=62
      dimLayer=shared, animator=null, continueDimming=false
      mDimSurface=Surface(name=DimLayerController/Stack=0) mLayer=110999 mAlpha=0.0
      mLastBounds=[-270,-480][1350,2400] mBounds=[-270,-480][1350,2400]
      Last animation:  mDuration=200 mStartTime=34184572 curTime=35019291
       mStartAlpha=0.6 mTargetAlpha=0.0
    Stack=0
      dimLayer=shared, animator=null, continueDimming=false
      mDimSurface=Surface(name=DimLayerController/Stack=0) mLayer=110999 mAlpha=0.0
      mLastBounds=[-270,-480][1350,2400] mBounds=[-270,-480][1350,2400]
      Last animation:  mDuration=200 mStartTime=34184572 curTime=35019291
       mStartAlpha=0.6 mTargetAlpha=0.0
    Task=63
      dimLayer=shared, animator=null, continueDimming=false
      mDimSurface=Surface(name=DimLayerController/Stack=0) mLayer=110999 mAlpha=0.0
      mLastBounds=[-270,-480][1350,2400] mBounds=[-270,-480][1350,2400]
      Last animation:  mDuration=200 mStartTime=34184572 curTime=35019291
       mStartAlpha=0.6 mTargetAlpha=0.0
    Stack=1
      dimLayer=shared, animator=null, continueDimming=false
      mDimSurface=Surface(name=DimLayerController/Stack=0) mLayer=110999 mAlpha=0.0
      mLastBounds=[-270,-480][1350,2400] mBounds=[-270,-480][1350,2400]
      Last animation:  mDuration=200 mStartTime=34184572 curTime=35019291
       mStartAlpha=0.6 mTargetAlpha=0.0

WINDOW MANAGER TOKENS (dumpsys window tokens)
  All tokens:
  Display #0
  WindowToken{2cbb668 android.os.BinderProxy@62938f9}
  AppWindowToken{4df35c8 token=Token{47c192d ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}}}
  AppWindowToken{f92e433 token=Token{a4766b5 ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}}}
  WallpaperWindowToken{ec08a81 token=android.os.Binder@178873c}
  WindowToken{2f47726 android.os.BinderProxy@2c6f5c2}
  WindowToken{bc87f67 android.os.Binder@af389a}
  WindowToken{bd9d114 android.os.BinderProxy@b1561e2}
  WindowToken{2ea4dbd android.os.BinderProxy@e2e8034}
  AppWindowToken{9051be2 token=Token{e661cad ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}}}
  AppWindowToken{6e77b06 token=Token{f0fb1e1 ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}}}
  AppWindowToken{e23349e token=Token{bd672d9 ActivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}}}


查看Activity#

adb shell dumpsys activity

主要关注

  • Running activities：该stack最近的Activity

    • TaskRecord：该stack最近的taskrecord

    • TaskId：#63 是com.shaunsheep.ams所在Task的TaskId

    • A：APP包名，com.shaunsheep.ams

    • StackId：Task所在的Stack栈

    • SZ：TaskRecord里面有几个Activity

      如Running activities有两个TaskRecod，#63有3个Activity，#62有2个Activity

      ActivityRecord的顺序从上往下看，MainActivity3、MainActivity2、MainActivity、HomeFirstSetWifiActivity、HomeUserProtocolActivity；

      TaskRecord的顺序从上往下看 #63 #62；

      Stack的存储顺序，就是从上往下看的ActivityRecord顺序，ActivityRecord中包含了TaskRecord信息，因此TaskRecord的展示是可以不连续的

      1
      2
      3
      4
      5
      6
      7
      8
      9
      Running activities (most recent first):
        TaskRecord{dbd02ff #63 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
          Run #4: ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}
          Run #3: ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}
          Run #2: ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}
        TaskRecord{9e28cc #62 A=com.unilife.fridge.haierbase.tft U=0 StackId=1 sz=2}
          Run #1: ActivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}
          Run #0: ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}

  • mResumedActivity：该stack栈顶的Activity

  • ResumedActivity：该stack栈顶的Activity

截取部分段落

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ACTIVITY MANAGER ACTIVITIES (dumpsys activity activities)
Display #0 (activities from top to bottom):
  Stack #1:
  mFullscreen=true
  isSleeping=false
  mBounds=null
    Task id #63
    mFullscreen=true
    mBounds=null
    mMinWidth=-1
    mMinHeight=-1
    mLastNonFullscreenBounds=null
      TaskRecord{dbd02ff #63 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.shaunsheep.ams/.MainActivity }
        Hist #2: ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}
          Intent { cmp=com.shaunsheep.ams/.MainActivity3 }
          ProcessRecord{25d8a2a 9459:com.shaunsheep.ams/u0a57}
        Hist #1: ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}
          Intent { cmp=com.shaunsheep.ams/.MainActivity2 }
          ProcessRecord{25d8a2a 9459:com.shaunsheep.ams/u0a57}
        Hist #0: ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}
          Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.shaunsheep.ams/.MainActivity }
          ProcessRecord{25d8a2a 9459:com.shaunsheep.ams/u0a57}
    Task id #62
    mFullscreen=true
    mBounds=null
    mMinWidth=-1
    mMinHeight=-1
    mLastNonFullscreenBounds=null
      TaskRecord{9e28cc #62 A=com.unilife.fridge.haierbase.tft U=0 StackId=1 sz=2}
      Intent { act=com.unilife.fridge.HomeUserProtocolActivity flg=0x10000000 cmp=com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity }
        Hist #1: ActivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}
          Intent { act=com.unilife.fridge.HomeFirstSetWifiActivity flg=0x10000000 cmp=com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity }
          ProcessRecord{60c9996 1341:com.unilife.fridge.haierbase.tft/u0a33}
        Hist #0: ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}
          Intent { act=com.unilife.fridge.HomeUserProtocolActivity flg=0x10000000 cmp=com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity }
          ProcessRecord{60c9996 1341:com.unilife.fridge.haierbase.tft/u0a33}

    Running activities (most recent first):
      TaskRecord{dbd02ff #63 A=com.shaunsheep.ams U=0 StackId=1 sz=3}
        Run #4: ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}
        Run #3: ActivityRecord{618c5c4 u0 com.shaunsheep.ams/.MainActivity2 t63}
        Run #2: ActivityRecord{40ee444 u0 com.shaunsheep.ams/.MainActivity t63}
      TaskRecord{9e28cc #62 A=com.unilife.fridge.haierbase.tft U=0 StackId=1 sz=2}
        Run #1: ActivityRecord{512920 u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeFirstSetWifiActivity t62}
        Run #0: ActivityRecord{4b852ec u0 com.unilife.fridge.haierbase.tft/com.unilife.fridge.haiercommon.ui.activity.guide.HomeUserProtocolActivity t62}

    mResumedActivity: ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}

  Stack #0:
  mFullscreen=true
  isSleeping=false
  mBounds=null

  ResumedActivity: ActivityRecord{f8b5f48 u0 com.shaunsheep.ams/.MainActivity3 t63}
  mFocusedStack=ActivityStack{868d01b stackId=1, 2 tasks} mLastFocusedStack=ActivityStack{868d01b stackId=1, 2 tasks}
  mCurTaskIdForUser={0=63}
  mUserStackInFront={}
  mStacks={0=ActivityStack{ce525e2 stackId=0, 0 tasks}, 1=ActivityStack{868d01b stackId=1, 2 tasks}}
  mLockTaskModeState=NONE  mLockTaskPackages (userId:packages)=
    0:[]
 mLockTaskModeTasks[]
  KeyguardController:
    mKeyguardShowing=false
    mKeyguardGoingAway=false
    mOccluded=false
    mDismissingKeyguardActivity=null
    mDismissalRequested=false
    mVisibilityTransactionDepth=0

Activity#
onBackPressed()
finish()
getTaskId 查看TaskId

UsageStatsManager#

Android获取栈顶程序
https://blog.csdn.net/ballonge/article/details/51085953
Android UsageStatsManager的简单使用
https://blog.csdn.net/shanfuming/article/details/58603450
http://blog.sina.com.cn/s/blog_7d95a2e70102vna4.html

task\stack#

task与stack有什么关系？

深入理解Android卷二 全文-第六章]深入理解ActivityManagerService_Innost的专栏-CSDN博客

Understand Android Activity’s launchMode: standard, singleTop, singleTask and singleInstance

tasks-and-back-stack

Application、Activity Stack 和 Task的区别

Android Stack与Task - 简书 (jianshu.com)

启动模式#

Activity启动模式singleTask的理解

Android启动模式之singleinstance的坑

好问题#

1.Stack、Task中，哪些因素影响Activity的展示顺序？

  • 启动模式
  • finsh、backPress
  • moveTaskToBack

2.SingleInstance使用越多越好吗？每个Activity都设置会怎么样？

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