Android, bring already started activity back to front

Question

My android application has multiple activities. Each activity has a 'Back to Home' button. For example, Main activity opens sub-activity A, sub-activity A opens sub-activity B.

On the screen of sub-activity B, there's a 'Back to Home' button which is supposed to bring back the Main activity into visibility.

I've tried the flag Intent.FLAG_ACTIVITY_REORDER_TO_FRONT but no use.

This is a part of my AndroidManifest.xml:

...
<activity android:name="vn.agritrade.Main_Activity"
android:label="Agritrade"
android:screenOrientation="portrait"
android:theme="@android:style/Theme.NoTitleBar.Fullscreen"
android:uiOptions="splitActionBarWhenNarrow"
android:launchMode="singleInstance">
  <intent-filter>
    <action android:name="android.intent.action.MAIN"/>
    <category android:name="android.intent.category.LAUNCHER"/>
  </intent-filter>
</activity>
...

This is how I relaunch the Main activity:

/**
 * Relaunch main activity (called by 'Back to Home' button)
 */
public void open_main_activity(View view) {
  Intent intent = new Intent(this,Main_Activity.class);
  intent.putExtra(DEFAULT_EXTRA,"");
  intent.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT);
  startActivity(intent);    
}

What else should I need?

Answer 1

Use below code it may help,

    Intent intentHome = new Intent(getApplicationContext(), MainActivity.class);
    intentHome.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    intentHome.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    intentHome.putExtra(DEFAULT_EXTRA,"");
    startActivity(intentHome);

It is worked for me.

Don't forget to mark as answer it is help to you.

Answer 2

Intent.FLAG_ACTIVITY_CLEAR_TOP may solve your problem

http://developer.android.com/reference/android/content/Intent.html#FLAG_ACTIVITY_CLEAR_TOP

Intent intent = new Intent(this,Main_Activity.class);
intent.putExtra(DEFAULT_EXTRA,"");
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent); 

Answer 3

My final solution is:

• Keep the main activity stay open
• Each time I need to turn back to main screen: close all sub-activities