taskAffinity和allowTaskReparenting的实例

为了想弄懂allowTaskReparenting，这几天看太多网上的文章，然后照着文章的实例码了一下，但还是试不出效果，其实归根结底都还是对这概念理解不够透彻。

于是按照自己的想法写了两个demo的应用，终于有点效果，废话不多说，直接看代码。

App1的代码如下：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.kv.app1">    <application android:icon="@mipmap/ic_launcher"        android:label="@string/app_name">        <activity android:name=".App1Act1">            <intent-filter>                <action android:name="android.intent.action.MAIN"/>                <category android:name="android.intent.category.LAUNCHER"/>            </intent-filter>        </activity>        <activity android:name=".App1Act2"  android:taskAffinity="com.kf.app" />    </application></manifest>

public class App1Act1 extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.act1);        findViewById(R.id.btn1).setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent(App1Act1.this, App1Act2.class);                intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);                startActivity(intent);            }        });    }}

public class App1Act2 extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.act2);        findViewById(R.id.btn1).setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent("com.kv.testme");                startActivity(intent);            }        });    }}

App2的代码如下:

<manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.kv.app2">    <application        android:icon="@mipmap/ic_launcher"        android:label="@string/app_name">        <activity android:name="com.kv.app2.App2Act1">            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>        <activity            android:name=".App2Act2" android:allowTaskReparenting="true">            <intent-filter>                <action android:name="com.kv.testme"/>                <category android:name="android.intent.category.DEFAULT"/>            </intent-filter>        </activity>    </application></manifest>

public class App2Act1 extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.act1);        findViewById(R.id.btn1).setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                Intent intent = new Intent(App2Act1.this, App2Act2.class);                startActivity(intent);            }        });    }}

public class App2Act2 extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.act2);    }}

于是操作步骤为：

启动App1，启动了App1Act1,点击进入App1Act2，再点击调用了App2的activity，App2Act2。

敲adb指令查看结果

adb shell dumpsys activity

结果如下

Task id #13828  TaskRecord{9214ad #13828 A=com.kf.app U=0 sz=2}  Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }    Hist #1: ActivityRecord{92909d8 u0 com.kv.app2/.App2Act2 t13828}      Intent { act=com.kv.testme cmp=com.kv.app2/.App2Act2 }      ProcessRecord{2e3f1818 31397:com.kv.app2/u0a1060}    Hist #0: ActivityRecord{32b8a59a u0 com.kv.app1/.App1Act2 t13828}      Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }      ProcessRecord{cd3d52c 31365:com.kv.app1/u0a1059}Task id #13827  TaskRecord{2b4db3e2 #13827 A=com.kv.app1 U=0 sz=1}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 }    Hist #0: ActivityRecord{38e9bc1d u0 com.kv.app1/.App1Act1 t13827}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 bnds=[21,86][273,371] }      ProcessRecord{cd3d52c 31365:com.kv.app1/u0a1059}

结论： App2Act2在名为com.kf.app的Task下面，与App1Act2处于同一个进程。

返回桌面，启动App2，发现App2的Act2Act2被打开了。

dumpsys activity结果如下：

Task id #13832  TaskRecord{3bfe2e7b #13832 A=com.kv.app2 U=0 sz=2}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app2/.App2Act1 }    Hist #1: ActivityRecord{27d7fc u0 com.kv.app2/.App2Act2 t13832}      Intent { act=com.kv.testme cmp=com.kv.app2/.App2Act2 }      ProcessRecord{31773b5f 32563:com.kv.app2/u0a1060}    Hist #0: ActivityRecord{ff9cceb u0 com.kv.app2/.App2Act1 t13832}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app2/.App2Act1 bnds=[283,86][535,371] }Task id #13831  TaskRecord{2b857498 #13831 A=com.kf.app U=0 sz=1}  Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }    Hist #0: ActivityRecord{9aac9ff u0 com.kv.app1/.App1Act2 t13831}      Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }      ProcessRecord{fe537b9 32532:com.kv.app1/u0a1059}Task id #13830  TaskRecord{36e924f1 #13830 A=com.kv.app1 U=0 sz=1}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 }    Hist #0: ActivityRecord{35c8a417 u0 com.kv.app1/.App1Act1 t13830}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 bnds=[21,86][273,371] }      ProcessRecord{fe537b9 32532:com.kv.app1/u0a1059}

可以看到，App2Act2又转移，回到了名为com.kv.app2 的Task里面，而不在com.kf.appTask，点击回退，发现App2的前面一个activity也被启动了。

如果将allowTaskReparenting设置为false呢？接着还是上面的步骤。

启动App1，启动了App1Act1,点击进入App1Act2，再点击调用了App2的activity，App2Act2。

敲dumpsys activity查看结果

Task id #13836  TaskRecord{6be6790 #13836 A=com.kf.app U=0 sz=2}  Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }    Hist #1: ActivityRecord{500f6ba u0 com.kv.app2/.App2Act2 t13836}      Intent { act=com.kv.testme cmp=com.kv.app2/.App2Act2 }      ProcessRecord{25b7b253 2602:com.kv.app2/u0a1060}    Hist #0: ActivityRecord{212508fe u0 com.kv.app1/.App1Act2 t13836}      Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }      ProcessRecord{3eb6108d 2550:com.kv.app1/u0a1059}Task id #13835  TaskRecord{c002889 #13835 A=com.kv.app1 U=0 sz=1}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 }    Hist #0: ActivityRecord{34e0fe77 u0 com.kv.app1/.App1Act1 t13835}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 bnds=[21,86][273,371] }      ProcessRecord{3eb6108d 2550:com.kv.app1/u0a1059}

和上面未启动App2时一样的结果，那么点击home退回桌面，如果这个时候启动App2，会是什么样的结果呢？

如下:

Task id #13839  TaskRecord{96f96e8 #13839 A=com.kv.app2 U=0 sz=1}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app2/.App2Act1 }    Hist #0: ActivityRecord{314c4e44 u0 com.kv.app2/.App2Act1 t13839}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app2/.App2Act1 bnds=[283,86][535,371] }      ProcessRecord{25b7b253 2602:com.kv.app2/u0a1060}Task id #13838  TaskRecord{23ee2101 #13838 A=com.kf.app U=0 sz=2}  Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }    Hist #1: ActivityRecord{3980b814 u0 com.kv.app2/.App2Act2 t13838}      Intent { act=com.kv.testme cmp=com.kv.app2/.App2Act2 }      ProcessRecord{25b7b253 2602:com.kv.app2/u0a1060}    Hist #0: ActivityRecord{39af1376 u0 com.kv.app1/.App1Act2 t13838}      Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }      ProcessRecord{22ad280b 3174:com.kv.app1/u0a1059}Task id #13837  TaskRecord{22388ba6 #13837 A=com.kv.app1 U=0 sz=1}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 }    Hist #0: ActivityRecord{1f089f69 u0 com.kv.app1/.App1Act1 t13837}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 bnds=[21,86][273,371] }      ProcessRecord{22ad280b 3174:com.kv.app1/u0a1059}

有没有发现，App2启动的界面，是App2Act1，所以App2下面的App2Act2没有换到Task为com.kv.app2下面，而是还在com.kf.app下面。

如果App2上，App2Act1界面点击进入App2Act2呢？结果如下：

Task id #13839  TaskRecord{96f96e8 #13839 A=com.kv.app2 U=0 sz=2}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app2/.App2Act1 }    Hist #1: ActivityRecord{4c04c71 u0 com.kv.app2/.App2Act2 t13839}      Intent { cmp=com.kv.app2/.App2Act2 }      ProcessRecord{25b7b253 2602:com.kv.app2/u0a1060}    Hist #0: ActivityRecord{314c4e44 u0 com.kv.app2/.App2Act1 t13839}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app2/.App2Act1 bnds=[283,86][535,371] }      ProcessRecord{25b7b253 2602:com.kv.app2/u0a1060}Task id #13838  TaskRecord{23ee2101 #13838 A=com.kf.app U=0 sz=2}  Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }    Hist #1: ActivityRecord{3980b814 u0 com.kv.app2/.App2Act2 t13838}      Intent { act=com.kv.testme cmp=com.kv.app2/.App2Act2 }      ProcessRecord{25b7b253 2602:com.kv.app2/u0a1060}    Hist #0: ActivityRecord{39af1376 u0 com.kv.app1/.App1Act2 t13838}      Intent { flg=0x10000000 cmp=com.kv.app1/.App1Act2 }      ProcessRecord{22ad280b 3174:com.kv.app1/u0a1059}Task id #13837  TaskRecord{22388ba6 #13837 A=com.kv.app1 U=0 sz=1}  Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 }    Hist #0: ActivityRecord{1f089f69 u0 com.kv.app1/.App1Act1 t13837}      Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x30200000 cmp=com.kv.app1/.App1Act1 bnds=[21,86][273,371] }      ProcessRecord{22ad280b 3174:com.kv.app1/u0a1059}

新建多了一个App2Act2实例。

通过以上的实验，相信对allowTaskReparenting有个印象的加深了吧。