CODEWITHSUNDEEP
androidandroid-activity
Bharath
Bharath

Reputation: 1807

Android: How to get back to the Calling Activity without using finish()

I call an activity called Activity1 from an Activity called MainActivity using the following:

Intent intent = new Intent(Intent.ACTION_VIEW, uri);
                    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    startActivity(intent);

So, when the control comes to Activity1. The normal activity lifecycle is started. i.e onCreate() is called and so on.

when i click the back button when the control is in Activity1. The finish method is called, which in turn calls the onDestroy() and now the control is back with the MainActivity screen. 

@Override
public void onBackPressed() {
        Log.d(TAG, "onBackPressed()");
        finish();
    }

The next time i call Activity1. The onCreate is called again as i called the onDestroy (when i pressed the back button) from the previous call.

Question: 1. is there a way to pass control back to the MainActivity when the back button is pressed without having to call the "finish()" method? 2. problem with calling finish, every time i call Activity1 from MainActivity, A new instance of Activity1 is created. that is the lifecycle again starts from onCreate().. i do not want this to happen as this is has become a major performance issue.

The main point i'm looking for is whether i can start the activity1 from the resume state rather than oncreate, when i call it after the first time.

Upvotes: 0

Views: 1755

Answers (2)

Luis
Luis

Reputation: 12058

in Actitity1 you define your WebView as:

private static WebView webView = null;

in onCreate() you only create it if it's null:

if(webView == null){
  //create webview and load from network
}

Use this approach wisely as it may easly lead to memory leaks if you point to objects in other activities, or objects that may be kept alive (runnables, messages, etc.)

Upvotes: 0

Jerad
Jerad

Reputation: 709

I don't believe you need to call the "finish()" method on onBackPressed. Android does that for you when you press the back button. The onBackPressed is used to last minuet tidy up (save stuff to sharepreferences, etc).

Android default behaviour is to call onCreate whenever a new activity is place on the screen. You cannot call a new Intent without this to happen.

I'm not sure why this is performance issue for you. Can you go in a little more detail what activity1 is doing? Are you doing heavy network communication? Is it possible you can cache the store results?

Upvotes: 1

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