android - 了解安卓 :launchMode

Question

我对 Android 中不同的 Activity 启动模式感到非常困惑。我知道它与 Activity 堆栈有关，这对我来说也不太清楚。如果能通过简单的用例对每个启动模式进行简短说明，我将不胜感激。

Answer 1

SingleTask and SingleInstance activities can only begin a task. They are always at the 
root of the activity stack. Moreover, the device can hold only one instance of the 
activity at a time — only one such task.

More Details

<application
    android:name=".MyApplication"
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">

    <activity android:name=".Standard">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>

    <activity
        android:name=".SingleTop"
        android:launchMode="singleTop" />

    <activity
        android:name=".SingleTask"
        android:launchMode="singleTask"
        android:taskAffinity="" />

    <activity
        android:name=".SingleInstance"
        android:launchMode="singleInstance" />      <!--//TODO launchMode -->

</application>

<uses-permission android:name="android.permission.GET_TASKS" />

Sample Demo