Android 多桌面图标启动, 爬坑点击打开不同页面

备注 ：
MainActivity 正常带界面的UI
MainActivityBt 和 MainActivityUsb  是透明的，即 android:theme="@style/TranslucentTheme"

###场景1:只有MainActivity 设置成：android:launchMode="singleTask"
点击顺序：MainActivity > home键 > MainActivityBt > home键 > MainActivityUsb
日志如下：

2024-03-03 21:22:11.724 15131-15131 MultipleIcon            pid-15131                            D  MainActivity.onCreate
2024-03-03 21:22:11.729 15131-15131 MultipleIcon            pid-15131                            D  MainActivity.onStart
2024-03-03 21:22:11.730 15131-15131 MultipleIcon            pid-15131                            D  MainActivity.onResume
---------------------------- PROCESS STARTED (15131) for package com.ifeng.multipleicon ----------------------------
2024-03-03 21:22:14.817 15131-15131 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onStart
2024-03-03 21:22:14.817 15131-15131 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onResume
2024-03-03 21:22:17.948 15131-15131 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onStart
2024-03-03 21:22:17.949 15131-15131 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onResume

日志简化图： 并没有执行MainActivityBt.onCreate 和 MainActivityUsb.onCreate；而且MainActivity只会执行一次。

###场景2:三个都设置成：android:launchMode="singleTask"

点击顺序：MainActivity > home键 > MainActivityBt > home键 > MainActivityUsb

2024-03-03 21:26:49.050 15690-15690 MultipleIcon            pid-15690                            D  MainActivity.onCreate
2024-03-03 21:26:49.057 15690-15690 MultipleIcon            pid-15690                            D  MainActivity.onStart
2024-03-03 21:26:49.057 15690-15690 MultipleIcon            pid-15690                            D  MainActivity.onResume
---------------------------- PROCESS STARTED (15690) for package com.ifeng.multipleicon ----------------------------
2024-03-03 21:26:52.114 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivityBt.onCreate
2024-03-03 21:26:52.117 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onStart
2024-03-03 21:26:52.136 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onNewIntent
2024-03-03 21:26:52.136 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onResume
2024-03-03 21:26:56.130 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivityUsb.onCreate
2024-03-03 21:26:56.133 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onStart
2024-03-03 21:26:56.143 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onNewIntent
2024-03-03 21:26:56.144 15690-15690 MultipleIcon            com.ifeng.multipleicon               D  MainActivity.onResume

日志简化图： 都有执行MainActivityBt.onCreate 和 MainActivityUsb.onCreate；而且MainActivity也成功跳转了！

！！！注意点：
#1. 多图标入口，需要跳转对应页面，入口Activity需要设置成singleTask， 否则只会唤起现有后台的页面。

#2. 多图标入口，如果是公用一个页面，刷新数据需要在onCreate 和 onNewIntent 中刷新UI。

详细代码：
Manifest配置文件：

<application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.MultipleIconApplication"
        tools:targetApi="31">
        <activity
            android:name=".MainActivityBt"
            android:label="BT"
            android:exported="true"
            android:launchMode="singleTask"
            android:theme="@style/TranslucentTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name=".MainActivityUsb"
            android:label="USB"
            android:exported="true"
            android:launchMode="singleTask"
            android:theme="@style/TranslucentTheme">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name=".MainActivity"
            android:exported="true"
            android:label="@string/app_name"
            android:launchMode="singleTask"
            android:theme="@style/Theme.MultipleIconApplication">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

MainActivity相关刷新UI代码 ：

class MainActivity : AppCompatActivity() {

    private val type : String?
        get() = intent.getStringExtra("TYPE")

    // 第一次打开需要在这里刷新
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        Log.d("MultipleIcon", "MainActivity.onCreate")
        syncTypeDisplay()
    }

    override fun onStart() {
        super.onStart()
        Log.d("MultipleIcon", "MainActivity.onStart")
    }

    // 当非首次进入时，需要在这里刷新
    override fun onNewIntent(intent: Intent) {
        super.onNewIntent(intent)
        // 需要使用setIntent(intent)赋值给当前Activity的Intent.否则，后续的getIntent()都是得到老的Intent。
        setIntent(intent)  
        syncTypeDisplay()
        Log.d("MultipleIcon", "MainActivity.onNewIntent")
    }

    private fun syncTypeDisplay() {
        findViewById<TextView>(R.id.tv).text =  when(type){
            "BT" -> {
                "蓝牙音乐"
            }
            "USB" ->{
                "USB音乐"
            }
            else -> {
                "收音机"
            }
        }
    }

    override fun onResume() {
        super.onResume()
        Log.d("MultipleIcon", "MainActivity.onResume")
    }
}