Understanding android:launchMode

Question

I'm getting really confused about the different activity launchModes in Android. I understand it has something to do with the activity stack which is also something not so clear to me. I would appreciate a short explanation about each launchMode with a simple use case.

i think the following is a good point to start: http://www.intridea.com/blog/2011/6/16/android-understanding-activity-launchmode — Manu Zi, Feb 24 '14 at 06:48

score 2 · Answer 1 · answered Sep 03 '19 at 12:36

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

score 0 · Answer 2 · edited May 11 '23 at 17:45

Android 4 types of launch mode:- 1.Standard
2.Single Top 3.Single Task 4.Single Instance

Standard -> When go to Activity A to activity B then new object create every time and when go back press go back multiple times.
Single Top -> when user to Activity A to activity B and again go Activity B then new instance not create and onCreate Method not call. but onNewIntent method
call.
Single Task -> when user to Activity A to activity B and acitivity B to activity C again go Activity B then new instance not create and onCreate Method not call. but onNewIntent method call. and when backpress on activity B then go to activity A. Activity C is remove from mid.
Single Instance -> Activity Stack B is A to B to C. After launching the B activity, A -> B -> C -> D — Job #1 B — Job #2 (Here, B will be assigned to a separate duty)

If you continue like this and add E and B, the stack will look like this: Job #1— A -> C -> D -> E. 5. List item

Understanding android:launchMode

2 Answers2