I want to send the user from application 1 to application 2 by pressing a button. In application 2, the user performs an action (for example, writes text), then he clicks the button and the text is sent to application 1.
I know that there is a certain "Getting a result from an activity", but I could not figure out how it works. I also found examples on YouTube where similar actions are performed, but inside one application. How can this be done using different applications?
You can launch an Activity using startActivityForResult(). The Activity that you launch does not necessarily need to be in the same application. When that Activity calls setResult() and then finish(), the information that was passed in setResult() will be returned to your original Activity in the method onActivityResult().
I'm sure that you can find some tutorials about how to use startActivityForResult().
Related
I am trying to send the string from one Activity to Another WITHOUT changing the CURRENT ACTIVITY. This my code I used:
Intent intent = new Intent(this, AnotherActivity.class);
intent.putExtra("getFollowerNumberData", txt);
startActivity(intent);
Using this code bring me to the other activity or I do not want that. I just want to send this string without changing activity. I tried this one
Intent intent = new Intent();
But it is crashing my app. First of all it is possible to do so? If yes, how can I achieve that?
Edit: To be more clear, it works like follower and Following features in other apps or games. When you follow someone the number of the person you just followed goes up as well your Following number. Since my SignInPlayerProfile.Class(where the Following should go up to one too) is in another activity I was trying to get this information intent.putExtra("getFollowerNumberData, txt); from Main Activity and display that in the SignInPlayerPlayer by using text.setText(). But the Problem is by using intent = new Intent(this, AnotherActivity.class); it brings me to SignInPlayerProfile Activity which I do not like since
I am trying to send the string from one Activity to Another WITHOUT changing the CURRENT ACTIVITY(or simpler words WIHTOUT Going to the Other Activity).
Thanks for Help.
When an activity getting closed, according to it's life-cycle, it will be destroyed and no longer exists, when you start an activity it will be created and then it can get your data, so you can't send data to an destroyed activity which no longer exists
You can use Static Variables to communicate between activities (Classes), you can change value of a Static-Variable of an activity from another activity, but it's not a good option for data you need to be alive because Static Variables lives on Heap Memory and Heap will be freed if Android OS needs more Memory
Another way is to create a Message Handler in your first activity as a Static Variable and then send a Message to the Handler from second activity, see this example :
http://stacktips.com/tutorials/android/android-handler-example
I suggest you using SharedPreferences for saving your data in first activity and load from it on second activity
EDIT :
According to your edit, the "Number" you want to use in another Activity as "Following" or "Followers" is just needed when the second activity is visible, you should use sharedpreferences to save the "Number" and load from it when you need it. For example before text.settext() method you can load the number from sharedpreferences and then pass it to text.settext()
You should not save your data on the variables or classes and should save them on a file like a Database or SharedPreferences then you can load them every time you want
Furthermore you can search about Activity life-cycle and see how to use life-cycle events like OnStart to load your data
Firstly please consider startActivityForResult() ,we can send information from one activity to another and vice-versa. As mentioned consider using shared_preferences for local in memory storage. To truly accomplish this feat in a elegant way though, do consider using obervables(rxandroid). You publish observations in one activity or fragment ,
then subscribe in another activity or fragment. I did not mentioned event bus nor otto since rxjava/rxandroid surpasses it. They act a promise context management system. Also because observable in process dependent consider using broadcast receivers, to broadcast events through out your application and external if so desired.
I'm developing a simple Application. It has 3 buttons (start record, stop record, send info to the server). I want to record my voyage on the map, and I implemented it, but it works only when Activity is onResume(), so now I implementing sticky service, which will do exactly the same, but in the background. So service will fill ArrayList<MapPoint>, and then I have to receive it back somehow to my activity. It is not necessary to pass ArrayList to Service, but I have to receive it back to send it to the server in onDestroy() method. Please, help.
I thinks you can put the value in shared preferences and then pull it back in the activity
I have been poking around to figure out how to do this with Service or Activity, or Broadcast Receiver and I can't seem to get a definitive answer.
I want to be able to write the following data event(s) with timestamp to a file with an application that is running in the background.
Power button pressed on
Call being sent outgoing
SMS message being sent outgoing
It is an application that I am attempting to build for logging phone usage with the timestamp written to a file.
Went through many explanations and this is the only one that seemed to make sense:
https://thinkandroid.wordpress.com/2010/01/24/handling-screen-off-and-screen-on-intents/
Any information or tutorials on this would be greatly appreciated.
I would do the following:
Create a broadcast receiver that based on the intent received determines the type of event. Have a look to the Command design pattern.
The command launches a new intent using the Broadcast receiver as a Context.
Create a service that is able to handle this intent, so it starts, sends some data or stores it wherever, and shutsdown. Have a look to the IntentService class.
Create an activity to show the content you have stored or to explain the user what your app does.
I'm planing some kind of information app for android and I'm not sure what technical design is best (because this is my first real android app).
The app which observes the latest information from an server consists of 4 screens:
Main screen -> shows the information (consists of a thread which updates the information by server push)
Configuration screen -> you come here from main screen if you'd like
to configure the information type you want to see.
message screen 1 -> you come here from main screen to send new messages to the server. The screen consists of a radiobutton list where you have to specify the type of information you have to send.
message screen 2 -> You come here from message screen 1. Here you can type the messages and send it to the server.
My thought is either using 4 Activities each containing one view or using just one Activity which contains a ViewFlipper of these 4 Views. What is the best approach and why?
Activities have their name for a reason. Each "action/activity" should be placed in a seperate activity. The user want's to configure something? Send him to the preference activity. The user wants to take a picture? Send him to a photo activity. And so on.
Therefore I think you should have 3 activities here when you split this by actions:
Main screen (user activity "read information/messages")
Configuration screen (user activity "change preferences")
Message screen (user activity "send a message")
For the last one you could use a ViewFlipper if you want to split the sending into two different layouts.
What advantages does this have?
Well, first of all you don't have a big ball of code in one activity that handles everything. Certainly that's possible, but can get somewhat ugly. Maintainablility here.
Also remember that we are still in a mobile environment. Yes phones are really powerful these days, but they still have very short run times on battery. So don't waste battery when you don't have to. Which would mean in case of one giant activity that everytime the user wants to send just a message, he has to load all the other stuff with it. Unneccessary code executed -> unneccessary CPU cycles -> battery drained for no reason.
Apart from that it's convinient for you because the framework supports you this way. For example: the backstack handles a lot of stuff for you already, e.g. you don't have to manage all the back-key logic (you would have to keep track of the layout and the back key depencies otherwise).
If you want to make use of androids intent system for 3rd party apps, this is also very useful. You can control access to your activities on a per-type basis. E.g. allow other apps to call your message activity, but not your preference activity. If you have one big activity this becomes difficult, with some intent extra parsing just to determine which screen the other apps intents to display. And that's propably the biggest reason why activities are activities. Apps can work on a action-base with each other.
This has probably been asked before, but I can't find a good way of implementing it. I'm trying to write a program that manages a form of messages, and these messages are received from an external data source. This all works. However, the problem comes when I try to notify the user: I would like to have the notification jump directly to the message when it is touched, but this seems to mess up the back stack. This is probably best explained by example:
I open up the message list, the main activity, and browse for a while.
I hit home and go into another app (let's say Music).
A new message is received. A notification comes up, which I touch. The message detail view is displayed.
Now I hit Back. What I want to have happen is that I return to Music, but unfortunately, Back sends me to the message list, and then hitting Back will return me to music.
The both the list and the detail activities are marked as "singleTop", and the exact flags that I use for the notification Intent are:
FLAG_ACTIVITY_NEW_TASK
FLAG_ACTIVITY_CLEAR_TOP
FLAG_ACTIVITY_SINGLE_TOP
I figure if the Messaging application can do this, why can't I?
I have found one way to do this, but it's still not ideal:
Change the detail activity to have a different task affinity from everything else.
Add android:launchMode="singleTop" and android:excludeFromRecents="true" to the detail activity's manifest entry.
(Optional) Modify the list activity to open the detail activity with FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET. (This makes the task more like the built-in messaging app.)
The only fault to this scheme is that switching back over to the app will always go back to the list activity, but at least it is consistent. If someone else has a better way to do this, I'd love to hear it.