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Passing data to other activity without opening it

I'm trying to pass the data from one activity to another activity without opening the activity. I tried it by not writing startActivity(intent) part but it fails.
How do I pass the data from one activity(1) to another activity(2) without opening that activity(2)?

Activities are UI elements so your question makes no sense. If you want perform some action that does not have UI create a service to perform the work and start or otherwise call that service from your first activity.
If you want to make data available to activity 2 when it does start, pick a persistent storage mechanism and write the data there, then read the data when activity 2 opens.
https://developer.android.com/guide/topics/data/data-storage
Alternatively, you can create a custom Application and store the data there and share it between activities.
Just a word of advice. You should describe what you are trying to accomplish not how you want to accomplish it. Activities are not the right tool for this task, but we can't suggest the right tool because we don't know what you want to build.

You can use events for passing around data. Either use the android native LocalBroadcastsSytem and put data as parcelable in the intent, or you can use any event library like EventBus

Pass the data from one activity to another activity without opening the activity try to do with the broadcast receiver or SharePhreferance or make that data public static You can access your data in anywhere of the application.

which is better to execute Database query on MainActivity or SubActivity

i currently following tutorial making notepad, this tutorial using 2 activity main activity and edit activity, edit activity is using to fill data for database , but the query is executed in main activity
so the data must sent back OnActivityResult from edit activity to main activity .
the main question is i want to know why we must pass data to main activity instead of execute insert or update query on edit Activity, is this the best way?,
Can anyone explain why?
Thanks

There you have the 2 activities, one (Main) is meant ust to display the notes, the other (Edit) will let the user to create the note. When the user confirms the creation of the new note in the EditActivity, it will finish and in the MainActivity's "onActivityResult" the notes will be loaded and displayed in the list. So if you want to separate the creation from the visualization of the (I highly suggest you to do this), you want this approach.

Passing data through multiple activities in android

I have application in which I have three activities. First and second activity have listview. I need selected values from the first and second activity in order to display some data in the third activity. Which is the best way to do this? Is it better to pass Intent from first to second activity, then from second to third activity or to use SharedPrefenreces?

This depends on what you need. If you need the data to be persistent in the event that your app is destroyed, then you will probably want to save the data in SharedPreferences (will also depend on what type of data since SharedPrefs aren't limited to what they can store) or a DB.
If you aren't worried about it being persistent then passing the data through Intent.putExtra() is fine. You can also create a Bundle and pass the Bundle through the Intent and add the data as you go.
You also have the option of creating a separate class which implements Serializable. Then you can create and pass the class Object through your Intents. Here is a post about doing that

Yes this can be achieved in many ways using:
Intents
Shared Preferences
Sqlite
Sqlite: You can use Sqlite to store data if the data is huge in first and second activity and retrieve the data in the third
activity (But if data is less this is not a feasible solution)
Shared Preferences: Here the data you have saved in the shared-Preferences is done in a xml file, so even if the app is
stopped the data is retained. This is helpful to save the password
and login details etc
Intents: My opinion Passing data with intents is much better option in your case because size of the data passed between your
first, second to third activity is less.
Finalizing :: Just put the data in bundle in first activity. Next get the data(Bundle) in second activity and add the data in second activity in addition to the data in the bundle received from first activity and pass that final bundle from second activity to the third activity.

In my opinion, it would be easiest to create an ArrayManager class, in which your variables are static. This way you can create methods to select and resize your arrays in the ArrayManager class. The only case in which this is bad is if you must hold references to Views, Contexts, or Activities (this will create a memory leak). In that case, codeMagic's solution is ideal.

In your case, if you need to pass same data from first activity to second activity then third activity & your data is small then I suggest use Shared Preferences.
If data passed from first activity to second activity is not same data of second activity to third activity then simply use intent.
There is a tricks. If your second activity always need data from first activity to operate then when you want to go back third activity to second activity then you will get stuck because from third activity you can not get first activity result. In that case saving data i mean Shared Preferences or Sqlite is best.
All above those scenario you need to find your own what is best to use for your app.

Update View with updated data in Android

I am noob in Android. Suppose I have two Activity in my android app.
Activity A and B, currently I am on Activity A then on click on one button I am now Activity B. Here From Activity B I want to update some view with updated data that is in Activity A. I got updated data in Activity B so Should I use here LocalBroadCastReceiver for this or anything ?? so that When I press back then app should show me updated data in Activity A
Should we use our custom callback here to update the UI view data of Activity A from Activity B ??

No, you shouldn't use BroadcastReceiver for that. The method depends on the size of data you want to transfer from Activity B to Activity A. If it's quite small, you can start Activity B with startActivityForResult and then get data back at the onActivityResult method (in Activity B you should use setResult once you are done). If the size of data is quite big, it's better to use DB for storing it instead of keeping it in memory.

okay , there are multiple ways to do it :-
you can use a static variable to store you data that too of application level ( might not be a good approach ) check the value of vairable in onResume() and set it to the view.
you can use sharedpreferences if your data is not that large , store the data in Activity B and fetch it on onResume() method of activity A.
as #nikis has told you
if your data is too large store it in db.
I dont think broadcastreceiver fits right in your scenario !!

When to use more Activities

I have an Activity which is an OpenGL view. I also have an xml layout to use for preferences. Until now, to show the preference menu, I just brought it to front by setContentView(). And the same to get back to the OpenGL view.
But is this a case where I should give the preference menu its own Activity?
I guess this would make a few things much easier. For example, the back button would just work, opposed to now where I have to code it or it will just exits the application.
And if this is a good idea, how do I pass data both ways? I have a class that store all preferences. Can I send it to the Activity and back again? Or is the best way to store the preferences in a sqlite database and then use it for passing data?

I find it easier to segregate menus and such into separate activities (unless you are using dialogs etc..) As far as storing data you can do it a number of ways:
Database
StoredPreferences
Intent extras with putExtra/Bundle
Creating an application subclass and storing preferences there
Each have their merit. 4 is pretty easy as you just have to state the application class name in your manifest then call: MyAppClass app = (MyAppClass)getApplicationContext(); and you can then use any variables in MyAppClass via app. 2 is also straightforward.

You already pointed out the main difference: history management.
You can pass data to Activity via Intents putExtra()/getExtra():
Create an Intend and add custom data via Intent.putExtra(..)
Start the new Activity: startActivityForResult(intent).
Inside new Activity you can get extra data with intent.getXyzExtra() (where xyz is type).
When new Activity is done just call setResult(int, resultIntent). Again you can add extra data as described in 1.
Call finish() to end the activity.
In original Activity method onActivityResult will be called. Again extract data from Intent as described in 3.