Can i call second activity from current activity without use intent? and why use intent, why not call second activity direct from the first activity?.
What does intent do in android?
Because to start any new Activity Android must have to go through the life cycle of an Activity. So it is necessary to use intent.
http://developer.android.com/reference/android/content/Intent.html
you can't ,see this link android is designed in this way to launch another activity
Intent says to Android you need open a new activity. Always when you need open a new Activity, you need "alert" the S.O before. Because of this we use Intent.
Activities doesn't work like a simple class, when we just instantiate.
This link will help you
http://www.vogella.com/tutorials/AndroidIntent/article.html
Related
I want to pass the WebView from One activity to another Activity.
how to do that. I referred How do I pass an object from one activity to another on Android?
but still not getting any idea for this. Please help me to get this....
Sounds to me like you may want a broadcast receiever...
try looking here: BroadcastReceiver
That will let one activity send a message to another
either u try to use finish() an the passed Activity or you simply call finish() in the activity after it's done with it's calculations
Are you sure you want that in an Android activity, not just a normal Java class?
Hi i am new to Android application development.In my Application i have two activity Activity1 and Activity2.From activity1 i call Activity2 as Intent.I want to access activity1 from this Activity(activity2) without going to first activity is there any posible way?Pls guide me
The only thing which make sence is passing data from Activity 1 to Activity 2. To do it just pass some data through the intent:
intent.putExtra("key", "Your data here");
in second activity:
String data = getIntent().getExtra("key");
If this is not the case, then your task is wrong somewhere. When activity gone background, there is no sence to interact with it.
No, there isn't. Activity1 might even have been shut down.
If you want to pass DATA between the two activities, that's of course doable. Either by passing data on with the intent, by using http://developer.android.com/reference/android/content/SharedPreferences.html or any other storage you can access from both activities.
If from your second activity wants to change something on the previous one, then, instead of using
startActivity(...);
you should use
startActivityForResult(...);
Maybe this link can help.
So you have the scenario where you start activity B from activity A and you want to change some parameters when activity B is done ( your changes can't be propagated in real time because you can't be sure what is the state of activity A ). So the best way to implement this is to use activity result - for more info about it check Android: Capturing the return of an activity
I want to call onCreate(Bundle cicici); from other class then i am getting "NullPointerException", so please guide me how can i call the onCreate() from another class.
There is only one way in which onCreate can be called, by starting an Activity, since onCreate is as part of Activity life cycle.
startActivity(new Intent(presentActivity.this, NextActivity.class));
if you want to call onCreate in order to actually present a new screen, then you need to create a the new Activity using the android framework style.
Ingredients:
1- An event to call your new activity( ie. onClickListener of a Button or list triggered)
2- On the event you need to create an Intent with the reference of the current activity and a class reference of your new Activity, example:
Intent intent =new Intent(CurrenActivity.this, MyNewActivity.class);
3- You need to call this activity depending on what you'll need you use startActivity or startActivityForResult, the last is use when you expect a response from your activity.
You can also refer to Android documentation Common Task, let us know if its helpful
It depends what you want to do in the second activity. If you want to create a simple task you can always use dialogs and you can show them inside your activity.
Or, on a second thought, you can hide some of your views and enable others but I guess that's not an orthodox solution :)
Is it possible to create implicit intent to call our own activity? If possible is it useful or better option is Explicit Intent?
please explain your situation more...
If a single Activity is there and you want to call the same activity again from this to have any refresh sort of thing...
Then its not a good idea...
All the views can be updated without calling the same activity again.
And if new view is to be generated then use another activity
How can I know what Activity has started the current Activity? Is there any specific method like, i.e. getIntent().getCallerActivity() or the only way is saving some information within the Intent using putExtra()?
Thanks.
There's getCallingActivity which you can use to get the name of the calling activity if you started the sub-activity with startActivityForResult.