CODEWITHSUNDEEP
androidandroid-activityandroid-intenttask
Brian
Brian

Reputation: 8085

Clearing task and start a new activity

I don't know why this is so difficult to figure out. I have my main activity that, when launched, checks if this is the first time it's been opened. If it is, then it closes the main activity and opens the setup/introduction activity with FLAG_ACTIVITY_NEW_TASK. The setup process consists of three activities (A, B, and C). At the end of activity C, how do I get it to clear and the setup task that contains A, B, and C and start the main activity again. I've tried adding FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_CLEAR_TOP to main activity Intent but when I press BACK, it returns to activity C of the setup process. How do I get it to clear the task of activities A, B, and C when C finishes and starts the main? Thanks!

I'm building in Android 1.6 (API 4), so some of the Activity flags may be limited.

Upvotes: 6

Views: 5283

Answers (4)

sidon
sidon

Reputation: 1482

Actually this can be achieved with startActivityForResult

public class A extends Activity {
   public onButtonClick() {
      startActivityForResult(new Intent(this, B.class), 0);
   }
   @Override
   protected void onActivityResult(int requestCode, int resultCode, Intent data) {
      super.onActivityResult(requestCode, resultCode, data);
      if (resultCode == RESULT_OK) {
         finish();
      }
   }
}

public class B extends Activity {
   public onButtonClick() {
      startActivityForResult(new Intent(this, C.class), 0);
   }
   @Override
   protected void onActivityResult(int requestCode, int resultCode, Intent data) {
      super.onActivityResult(requestCode, resultCode, data);
      if (resultCode == RESULT_OK) {
         setResult(RESULT_OK);
         finish();
      }
   }
}

public class C extends Activity {
   public onButtonClick() {
      setResult(RESULT_OK);
      finish();
   }
}

I think this is the right way, you don't leak anything this way.

PS: I know this is old post, but maybe someone will find this useful.

Upvotes: 1

Arun
Arun

Reputation: 1668

class A extends Activity { 
public static Activity instanceOfA = null;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    instanceOfA = this;
}
}

class b extends Activity { 
public static Activity instanceOfB = null;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    instanceOfB = this;
}
}


class c extends Activity { 
public static Activity instanceOfC = null;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    instanceOfC = this;
}
}

Now suppose you want to clear all the task from your current activity, then call instanceOfA.finish(); instanceOfB.finish(); instanceOfC.finish();

Upvotes: 0

Arun
Arun

Reputation: 1668

FLAG_ACTIVITY_CLEAR_TOP will clear activities it it is of the same activity instance. Here in your case all your activities are of different instances so FLAG_ACTIVITY_CLEAR_TOP won't work. To clear your task, create an Activity instance in each of your activity and assign that instance 'this' on your onCreate method of every activity. whenever you want to clear your task jus call that instance.finish(). and start the activity that you want.

Upvotes: 2

Squonk
Squonk

Reputation: 48871

I answered a similar question here

As Mudassir says in their comment just finish() your activities immediately after starting a new one.

Upvotes: 0

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