What is proper way to exchange data or objects between different Android Activities?
Welcome screen <-> Main Screen <-> Startup routines <-> Processing data <-> Settings
Is it normal/recommended to have more than one activity in Android app? in my opinion, it's somehow strange to have this model of data exchange inside application
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I am trying to pass a custom object to one activity from another. What I would like to use is the HashMap of WeakReferences, but the description isn't clear, at least to me. From above URL: "A HashMap of WeakReferences to Objects. You can also use a HashMap of WeakReferences to Objects with Long keys. When an activity wants to pass an object to another activity, it simply puts the object in the map and sends the key (which is a unique Long based on a counter or time stamp) to the recipient activity via intent extras. The recipient activity retrieves the object using this key."
MyObject object = new MyObject(); HashMap map = new HashMap(); WeakReference reference = new WeakReference(object); map.put(reference.hashCode(), reference);
Intent i = new Intent(myIntent); i.putExtra(map);
I know this is probably way off but I can't figure out how this is intended to be implemented based on the description. Are the keys hashcodes, user defined, or what? It sounds like all that is passed is a HashMap containing the key values but how is the object retrieved with just the key? I couldn't find any code examples or useful documentation on this method of passing objects
It would be nice if StackOverflow had a section where we could post tutorials like mine so that I can answer literally hundreds of questions that have been asked here with a single blow. See... every day I read questions about how to pass complex objects between activities, how to save state so that your app can resume after orientation change, how to update listviews when the data changes, etc, etc. Here is the second part of a tutorial series I posted on my blog... I hope that you actually read it... because I haven't seen any examples like it anywhere... and it has changed how I think about developing for Android across the board. The question is... is there a downside or negative affect of developing like this?
Beyond Smart Lists - How Observable Singletons change the game. Please read through both of these tutorials carefully... I will answer any questions about it here that I can... I really want to know what you think about this and if it might solve issues for you. NOTE TO MODERATORS: there are no advertisements of any kind on my blog.. so don't just close this because you think I am spamming somehow... I am not going to duplicate my post here.
The FAQ mentions a method of passing objects around activities. (It is not clear to me): "A HashMap of WeakReferences to Objects. You can also use a HashMap of WeakReferences to Objects with Long keys. When an activity wants to pass an object to another activity, it simply puts the object in the map and sends the key (which is a unique Long based on a counter or time stamp) to the recipient activity via intent extras. The recipient activity retrieves the object using this key.".................
View 7 Replies View RelatedI want to pass an object from Activity B to Activity A. Scenario:
- Activity A calls Activity B
- User selects item in Activity B
- Activity B passes an object to Activity A
How do I accomplish this? And in which method do I read in the passed object in Activity A?
I am trying to pass a user defined object to another activity Bundle bundle = new Bundle(); bund.putSerializable("myData", myData); intent.putExtra("bundle", bundle); where myData class implements Serializable interface. I am getting following error: java.lang.RuntimeException: Parcelable encountered IOException writing serializable object how to pass complex objects between activities?
View 7 Replies View RelatedI have written my application logic in domain objects (to enable multiple user interfaces and porting to other platforms), and am now lookng at implementing Activities for the user interface.
Considering that each activity needs to serialise its state, what is the best way to ensure my domain objects are only serialised once?
How to pass socket, inputstream, outputstream objects between activities
View 1 Replies View Relatedhow to call BarCodeScanner, and return the value to a field.so now, i have a toast that says "successful scan" and then i want to pass the result to a new activity. when i comment out my intent, everything works (minus the passing of data/switching of screen, obviously) but when i run my project as is, it FC's no errors reported by eclipse in code or xml. any insights?
View 2 Replies View RelatedHow to pass data between activities in an Android application?
View 1 Replies View RelatedWe're designing an Android app that has several activities which are working in a wizard like way - user should pass from the activity #1 to activity #5 to get to the final activity (#6).
Since we know an activity can be suddenly terminated by OS on low memory we used Application class as a static storage for keeping the data the user inputs on "wizard" activities and other data our app needs for the whole session.
Unfortunately we've discovered this approach fails - looks like the Application class instance is also can be killed by OS (this was specifically discovered on Android 1.6 versus 1.5). Are our expectations wrong on this approach (we think Application class instance always lives for the whole app session)?
So the question is - what is the best practices on Android to keep data between activities deathes/restarts for the whole application session?
i need to parse this response in android using the android json parser but the thing i cant find the answer to anywhere is: how do i parse the data if for example "itineraries" can contain one or sometimes more objects of the type itinerary? if it contains one than it is returned like this but if it contains more it is returned with [] with this example "itinerary" cannot be placed into a JsonArray becouse obviously it is not an array. (not placed in [] right?)
how do i parse this? any examples?
{
"plan":{
"date":"2010-10-20T00:00:00+02:00",
"from":{
"name":"Булевар Партизански Одреди",................
I would like to know what is the best and fastest way to exchange data between services. I have been trying to bind one service to another using ServiceConnection but the actual connection never happened. Also I did not saw anything strange in LogCat.
View 1 Replies View RelatedIntents in Android are an elegant way to pass messages between uncoupled components, but what if you want to send extra data with the Intent? I know you can add various value types, and objects that implement Parcelable, as extras, but this doesn't really cater for sending user defined types locally (i.e. not over a remote interface). Any ideas?
View 3 Replies View RelatedI have an application that have a Google map on Google Android 1.5 since we have been working on the application for a long time, we are not in stage of upgrading to the newest framework, so we are using 1.5. Now, I have map locations that are dynamically generated and drawn on the map at run-time to visualize some streams, Up to this point the application is working fine, Now my problem is that I am trying to filter the objects ( addresses) to visualize only the on-screen ones. I do NOT want to visualize the addresses that are off-screen. The way I am trying to do this is to check the screen-coordinates of each object (address) before visualizing it, then it the coordinates (x,y) more than (0,0) and less than (320, 460). I should visualize it. I am trying to use this approach, but it is not working for some reasons, I have tried many posts but could not understand why, there must be something missing somewhere that I am not aware of.
View 11 Replies View RelatedIs it possible to transfer data between activities without using "extars"? I need to access MyOwnObject in Atctivity 1 from Activity2 Possible with using static fields?
View 6 Replies View RelatedThe main activity includes some variables with set values. I created a sub-activity with the form which has to be filled with the data from main activity so I guess the data have to be passed to the sub-activity when it starts. how to pass the variable values to the sub-activity from the main activity?
View 1 Replies View RelatedI'm developing an app which basically navigates through a xml-feed. When I parse the feed or let's say the list, then each (list)item becomes a model. All the models are wrapped up in an array list. Now, when the user clicks on a list item, the underlying model is going to be serialized and sent as IntentExtra to the next Activity (e.g. a deeper sub list). (Originally I asked here a different question. The solution was not related to Serializable and wouldn't help anybody. However MatteKarla gave an interesting input. Thats why I decided to rewrite this question.)
View 1 Replies View RelatedI was playing a bit with adapters cursors and activities. Let's assume i have a cursor containing a query I've made (it doesn't matter if it's to DB or content provider). Now lets assume i bind some of the data (first two rows) to a list activity. Every click on one of those items should open a new list activity (i pass on the cursor index in the activity bundle). Now the question is, which sharing method will be most efficient and right from code point of view ?
1. I thought of trying to send the cursor object in the intent itself (hoping it implemented runnable) but I'm not so sure it's that efficient since the query may contain many rows which will need to be parceled, and i the other intents uses only a few (say 4-5 columns of each row) it's a real waste.
2. Thought of trying to create the array list for my other list screen adapter and serialize it to the intent (again use serialize and intent to pass on the data) but again i fear for efficiency penalty.
3. my last solution was to use static cursor member in my first activity, with package permission, it will work and be relatively efficient, but I'm not so sure regarding memory efficiency and code structure, i'm not fond of using static variables in any case.
Is there another sharing method that i don't know off, if two activities share the same process and application, then they also share memory space, then it should be easy to pass variables from one to another, the question is what's the easiest way without serializing ?
I did some digging, but couldn't find a clear answer. I have an application with TabActivity as the main activity. I have some computing and network communication that needs to be done when user clicks on the big red jolly "DO IT" button. One tab hosts the form with "DO IT" button, while the other tabs display the results from computing (each tab displays different part of results). The computing is done as AsyncTask as it's supposed to be (afaik).
Now the question is, what is the best way to share the results between the tabbed activities? It can be done with ContentProvider + database from what I have read, although that seems like a bit too much for my needs. I have also considered an option to save the results to some cache file activities could read in onCreate, onResume etc and display the data. Are there any other convenient ways to share the data? (To make it more clear, the data aren't simple, so doing it through preferences etc is impossible.)
I was looking out for ways to share data between various activities that one may need to create for his applications . Using "Parcel" and Bundle one can do data exchange , but looks like this is a bit cumbersome process specifically if you have to share large array objects with too many fields.
As android.app.Application maintains global state for the application , we can use this class to store global data and access it across activities. Is this a good way ? Are there any implications on allocating large objects in the your class which extends from android.app.Application ?
I have a TabActivity, and the tabs point to sub activities. Is there a way I can send a 'message' to those child activities? I just want to pass a string across, not sure if this is possible.
I have some data being fetched by the parent TabActivity, and the child tabs can't do anything useful until the parent is done fetching. When fetching is complete, I'd like to pass that data to the child activities so they can do something useful with it.
Normally I'd set the data to be passed in the Intent when first creating the activity, but in this case I can't do that.
I am working on a small android project where it is necessary to share some data amongst several activities and a service that runs in a separate process. I would just like to know what are my options in terms of sharing data? Application class? IPC? File-based? Broadcasts?
View 3 Replies View RelatedI have been using SharedPreferences to share data between activities. But I would very much like to find a better way. I would simply like both Activity1 and Activity2 to share Object1. Activity1 will create Object1 and then start Activity2. What is the smartest way to give Activity2 a pointer to Object1?
To summarize: Activities don't have constructors! How do I send data to them from their parent activity?
I am working on an android application, where there are 4 activities. Activity1 is main activity and there are different buttons on that activity which can open other activities. Other 3 activities can also open each other. There is a thread running in Activity1 which returns some counter. I need to show that counter on all activities. At an specific time, the thread doesn't know which activity is at top. What is the right way to control this scenario, such that thread output should update on all activities, no matter which one is at top?
View 1 Replies View RelatedI have just started doing some Android development. One of the things that I would like to add to the app the I'm working on, is data exchange between a desktop computer and an android phone. Think of it like syncing data between Microsoft Outlook and the phone when it is connected to the wifi network. (Stanza on the iPhone is another good example)
The application that is running on the desktop is written in C# (to make it more interesting ;-)). I'm trying to avoid using a WebService, since this requires something like IIS.
Are there any libraries that can help me with this, or is it simple enough to do using the Java Socket functionalities?
How to get a live exchange rate data and apply it to an Android App? Currently creating a currency exchange as my project.
View 2 Replies View Relatedi have a scenario of login page after logging in there will be sign out button on each activity. on clicking signout i will be passing session id of signed in user to signout. can any one guide me how to keep session id available on all activities??
View 3 Replies View RelatedI've never built a game before, and I've not programmed for Android before but am looking to do so over the summer by building a game. What type of object do I use for a shape that I want the user to be able to drag around the screen for instance using touch gestures? How do I tie together the MotionEvent, View and Graphics2D to make objects drawn on screen that can be interacted with? I imagine this will use ActionListeners / Handlers but I'm a bit confused at this stage.
View 1 Replies View RelatedI have an app fetch data from internet, for better performance and bandwidth, I need to implement a cache layer.
There are two different data coming from the internet, one is changing every one hour and another one does not change basically. So for the first type of data, I need to implement an expire policy to make it self deleted after it was created for 1 hour, and when user request that data, I will check the storage first and then goto internet if nothing found.
I thought about using a SharedPrefrence or SQLDatabase to store the json data or serialized object string.
My question is:
1) What should I use, SharedPrefrence or SQLDatabase or anything else, a piece of data is not big but there are maybe many instances of that data.
2) How to implement that expire system.