应用后台时双Launcher图标行为异常问题求助

我的Android应用有2个Launcher图标，操作步骤如下：

• 点击Launcher图标1，打开MainActivity；
• 按下Home键将应用置于后台后，点击Launcher图标2，应用仅回到前台，并未打开对应的SecondActivity。

需求：即使应用处于后台，点击对应Launcher图标也需打开相应的Activity。

已尝试设置android:clearTaskOnLaunch="true"并使用onNewIntent方法，但点击Launcher图标2恢复应用时该方法并未触发。

日志信息 #

---------------------------- PROCESS STARTED (10945) for package com.example.twolaunchericonapplication ----------------------------
//click on launcher icon 1
2023-10-17 07:51:09.581 10945-10945 First                   com...le.twolaunchericonapplication  E  onCreate
2023-10-17 07:51:09.602 10945-10945 First                   com...le.twolaunchericonapplication  E  onResume: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.twolaunchericonapplication/.MainActivity bnds=[582,785][859,1205] }
// click launcher icon 1 again
2023-10-17 07:51:22.113 10945-10945 First                   com...le.twolaunchericonapplication  E  onNewIntentIntent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10600000 cmp=com.example.twolaunchericonapplication/.MainActivity bnds=[582,785][859,1205] }
2023-10-17 07:51:22.113 10945-10945 First                   com...le.twolaunchericonapplication  E  onResume: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.twolaunchericonapplication/.MainActivity bnds=[582,785][859,1205] }
// click launcher icon 2
2023-10-17 07:51:31.277 10945-10945 First                   com...le.twolaunchericonapplication  E  onResume: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10200000 cmp=com.example.twolaunchericonapplication/.MainActivity bnds=[582,785][859,1205] }

Manifest配置 #

<activity
    android:name=".MainActivity"
    android:exported="true"
    android:label="First Activity"
    android:launchMode="singleTop"
    android:clearTaskOnLaunch="true"
    android:theme="@style/Theme.TwoLauncherIconApplication">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>
<activity
    android:name=".SecondActivity"
    android:exported="true"
    android:launchMode="singleTop"
    android:clearTaskOnLaunch="true"
    android:label="Second Activity"
    android:theme="@style/Theme.TwoLauncherIconApplication">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

代码实现 #

class MainActivity : ComponentActivity() {

    override fun onNewIntent(intent: Intent?) {
        super.onNewIntent(intent)
        Log.e("First","onNewIntent"+intent)
    }

    override fun onResume() {
        super.onResume()
        Log.e("First","onResume: "+intent)
    }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        Log.e("First","onCreate")
        setContent {
            TwoLauncherIconApplicationTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    Greeting("First")
                }
            }
        }
    }
}
class SecondActivity : ComponentActivity() {
    override fun onNewIntent(intent: Intent?) {
        super.onNewIntent(intent)
        Log.e("Second","onNewIntent"+intent)
    }

    override fun onResume() {
        super.onResume()
        Log.e("Second","onResume :"+intent)
    }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        Log.e("Second","onCreate")
        setContent {
            TwoLauncherIconApplicationTheme {
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    Greeting("Second")
                }
            }
        }
    }
}

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {
    Text(
        text = "Hello $name!",
        modifier = modifier
    )
}

@Preview(showBackground = true)
@Composable
fun GreetingPreview() {
    TwoLauncherIconApplicationTheme {
        Greeting("Second")
    }
}

解决方案 #

问题根源在于：两个Launcher Activity默认共享同一个taskAffinity，系统会复用已有的Task将应用带到前台，而非启动目标Activity。需通过以下配置修改：

1. 修改Manifest配置 #

给两个Activity设置不同的taskAffinity，并将launchMode改为singleTask，移除clearTaskOnLaunch属性：

<activity
    android:name=".MainActivity"
    android:exported="true"
    android:label="First Activity"
    android:launchMode="singleTask"
    android:taskAffinity="com.example.twolaunchericonapplication.main"
    android:theme="@style/Theme.TwoLauncherIconApplication">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>
<activity
    android:name=".SecondActivity"
    android:exported="true"
    android:label="Second Activity"
    android:launchMode="singleTask"
    android:taskAffinity="com.example.twolaunchericonapplication.second"
    android:theme="@style/Theme.TwoLauncherIconApplication">
    <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
    </intent-filter>
</activity>

配置说明 #

• taskAffinity：指定Activity所属的Task分组，不同值会让系统为每个Launcher图标创建独立的Task，点击时系统会匹配对应Task，而非复用已有Task。
• launchMode="singleTask"：确保每个Activity在对应Task中仅存在一个实例，点击Launcher图标时，若对应Task已存在则将其带到前台并调用onNewIntent；若不存在则创建新Task和实例。

2. 验证效果 #

修改后：

• 点击图标1启动MainActivity，后台后点击图标2，系统会启动SecondActivity所在的独立Task；
• 再次点击对应图标，会直接唤起对应Task的Activity，并触发onNewIntent方法。

内容的提问来源于stack exchange，提问作者RAMU