Tutorial :Can I force the Android Back button to go two steps back in the Activity stack?



Question:

I know that I can override the onKeyDown method, but I want Back to do it's thing, just twice!


Solution:1

FirstActivity

Intent intent = new Intent(FirstActivity.this, SecondActivity.class);  startActivity(intent);  

SecondActivity

int REQUEST_CODE = 123  Intent intent = new Intent(SecondActivity.this, ThirdActivity.class);  startActivityForResult(intent, REQUEST_CODE);  

(to make this pedagogic there is more code for this activity below)

ThirdActivity

@Override  public void onBackPressed() {      // Semi ugly way of supporting that back button takes us back two activites instead of the usual one.      setResultOkSoSecondActivityWontBeShown();      finish();     }    private void setResultOkSoSecondActivityWontBeShown() {      Intent intent = new Intent();      if (getParent() == null) {      setResult(Activity.RESULT_OK, intent);      } else {          getParent().setResult(Activity.RESULT_OK, intent);      }  }  

SecondActivity (again)

@Override  protected void onActivityResult(int requestCode, int resultCode, Intent data) {      if (requestCode == 123) {          if (resultCode == RESULT_OK) {              finish();          }      }  }  


Solution:2

I am thinking of it this way:

A -> B -> C  

A, B, C activities.

You can't do a back twice since the first onKeyDown() will be executed in C and the second one should be executed in B.

I don't know why you are trying to do, but here are some options.

  1. Using the android:noHistory tag:

    Perhaps your C activity is doing something that doesn't need a view and that's why you want to back twice.

  2. Using an intent. Something like:

    Intent intent = new Intent(C.this, A.class);  startActivity(intent);  
  3. Using the finishActivityFromChild(). I have never try it, but it looks like you can use it to decide what to do on B depending of how C ended.


Solution:3

|*| Going back one screen or end activity :

finish();  

|*| Going back more than one screen :

You can go back to which ever screen you need using intent and use flags to prevent going back to same screen :

Intent gotoScreenVar = new Intent(goFromScreenCls.this, goToScreenCls.class);    gotoScreenVar.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK);    startActivity(gotoScreenVar);  

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