I have read quite a good books & blogs about the Background work process in Android and updating the UI.
I have learned few way like using a Service with Intent, Using AsynTask, Using a Bind Service with a Intent and so..
What is the rule of thumb using this, i mean when to use what?
I am just learning to code in JAVA & Android.
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I've got an Android activity which grabs an RSS feed from a URL, and uses the SAX parser to stick each item from the XML into an array. This all works fine but, as expected, takes a bit of time, so I want to use AsyncActivity to do it in the background. The line items = parser.getItems() works fine - items being the arraylist containing each item from the XML. The problem I'm facing is that on starting the activity, the ProgressDialog which i create in onPreExecute() isn't displayed until after the doInBackground() method has finished. i.e. I get a black screen, a long pause, then a completely populated list with the items in. Why is this happening? Why isn't the UI drawing, the ProgressDialog showing, the parser getting the items and incrementally adding them to the list, then the ProgressDialog dismissing?
View 3 Replies View RelatedI'm having a problem when trying to stop location updates when the app goes into the background. In my onCreate() method I start request updates like this:
CODE:........
However the GPS icon remains in the status bar and the only way to get rid of it is to manually kill the application.
I'm not sure if anyone is able to answer this confidently, maybe those that have older unlocked Android phones can give some insight. I'm looking at buying an unlocked Hero from mobile phones direct.co.uk, whenever they start selling them. I'm only hesitant about what if any support I'd lose from not buying directly from a carrier. How do Android OTA updates work on unlocked phones? Also, can anyone speculate yet how HTC is going to be handling its updates? Will it push through the carriers? If I buy unlocked and get a contract through Voda phone (who is not officially carrying the phone) will I be the last one on the block to get my updates? Or will I need to root my phone and install them all myself?
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View 1 Replies View RelatedI will be buying a brand new unlocked htc desire from an asian country.will it work fine in india(where it is yet to be launched) and will it receive froyo 2.2 as soon as it is made available worldwide?
View 1 Replies View RelatedIn my application I want to send sms, but the application must have to run in the background. It send the sms but it is not run in the background. I have following code...
View 2 Replies View RelatedIt is possible to block all the background work dolphin do with ads and the other uneeded service wich use data and battery?
Suppose you leave dolphin open on a simple page while you are readind he is continuosly using your system even if you don't need...It's really heavy specially for the battery.
The layout and options as auto Fullscreen are amazing but i would like it working as the stock browser without connecting in the background with the dolphin server without permission...
GT-I9505
I am developing my first Android App and I need a ProgressDialog to be showed while a background task, in this case just a http call on the server, happens.
I did a bit of studying on this and also have already checked other threads related to this subject.
http://developer.android.com/reference/android/os/AsyncTask.html
[url]
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Among others.
Than I got to write a bit of code:
1) In My Activity I declare a variable to be of type ProgressDialog
code:............
2) I have also written an inner class to extend AsyncTask as required, here in the doInBackGround is where I call a static method which actually do the POST http request to the server, in the server side I have blocked the server response 20s to validate the progress dialog.
code:............
3) When the button is pressed I than build the ProgressDialog anc call the AsyncTask I have created:
code:...................
Well, this is it, I believe this was suppose to show a progress dialog while the AsyncTask would query the server in background, but what I get is NO progress bar until server response arrives and than for a fraction of time(less than 1 second) the progress shows and the next Activity is called.
I have written a very simple game with some simple animations, but I've noticed that when the phone checks email, or several other apps are running, the animations that update in my thread start behaving slowly or choppy. This is a problem as the game mechanic requires some careful timing of your screen touches based on the animations. So if it starts behaving erratically, the game doesn't really work well - and isn't much fun.
Is there a way to prevent this? Can my threads have a higher priority when they need to run?
Im using a web service, so I want to use an async thread for the HTTP authentication request and another thread later to make additional service requests while my main thread runs.Would like to see a good example of how to do this and how to show busy messages somehow in main app. How does the main app know when the thread finished? And what if my thread encounters exceptions, how do I deal with that?HTTP requests are sent later, use the same cookies setup up by the first auth request, so will the later requests pick up the same cookies and just work?
View 2 Replies View RelatedI just have a concern about AsycnTask. If i have one activity which starts a async task. Now that activity goes in background and new activity gets opened & visible to us.
So the async task opened by previous activity stops or it still keeps going in background or it pauses or stops ?
In the documentation, I read that it is not possible for executing 2 Async Tasks. If execute is called again, it should throw an exception.
The following is given under the heading of "Threading Rules", and i quote:
"The task can be executed only once (an exception will be thrown if a second execution is attempted.)"
I wish to understand the meaning of this statement.
Does this mean, that if i try and execute the same task twice (concurrently) when the first execution of the task was still going on...an exception will be thrown ? Will i need to wait for the completion of the first task, before i spawn a second task ?
A possible use case:
The user wishes to download a set of files. He clicks on the download button by providing the URL. When the first download is still going on, he wishes to download another file and provides another URL. Both these user actions are serviced by a DownloadTask, that extends the AysncTask.
If i wish to change this default behavior, is there a configuration option?
Setting the background color programatically of an android TextView doesn't seem to work.
I'm I missing something!
CODE:.............
I also have this file (colors.xml) in my res/values folder
CODE:................
Also, setting the text color causes the TextView to disappear.
CODE:..................
How do you create unit tests for an Android activity that starts async tasks in onCreate? I would like to test the result of these tasks.
View 1 Replies View RelatedI am developing a program that needs async socket. I am new to Android and Java. As I can see in the document, to write network program, I got Socket and SocketChannel, but it seems they are all sync socket, it means, I need an extra thread to call blocking read, write... and etc. Here comes the problem, my program is a chat room, the communicate is not linear, I have no idea when the server will send a message to me, if I read in that thread to wait message from server, but the user want to send message to server, the reading function blocked forever, if there is no incoming data, then the pending outgoing message will not be sent. That's why I need async socket. So my question is: How to write async socket under Android environment?
View 8 Replies View RelatedI've got the URL of a .png image, that needs to be downloaded and set as a source of an ImageView. I'm a beginner so far, so there are a few things I don't understand:
1) Where do I store the file?
2) How do I set it to the ImageView in java code?
3) How to correctly override the AsyncTask methods?
What is the difference between Service, Async Task & Thread. If i am not wrong all of them are used to do some stuff in background. So, how to decide which to use and when?
View 2 Replies View RelatedI read somewhere (and have observed) that starting threads is slow. I always assumed that AsyncTask created and reused a single thread because it required being started inside the UI thread.The following (anonymized) code is called from a ListAdapter's getView method to load images asynchronously. It works well until the user moves the list quickly, and then it becomes "janky".final File imageFile = new File(getCacheDir().getPath() + "/img/" + p.image);image.setVisibility(View.GONE);view.findViewById(R.id.imageLoading).setVisibility(View.VISIBLE);
(new AsyncTask<Void, Void, Bitmap>() {
@Override
protected Bitmap doInBackground(Void... params) {
try {Bitmap image;
if (!imageFile.exists() || imageFile.length() == 0) {
image = BitmapFactory.decodeStream(new URL(
"http://example.com/images/"
+ p.image).openStream());
image.compress(Bitmap.CompressFormat.JPEG, 85,
new FileOutputStream(imageFile));
image.recycle();
}image = BitmapFactory.decodeFile(imageFile.getPath(),
bitmapOptions);
return image;
} catch (MalformedURLException ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
return null;
} catch (IOException ex) {
// TODO Auto-generated catch block
ex.printStackTrace();
return null;
@Override
protected void onPostExecute(Bitmap image) {
if (view.getTag() != p) // The view was recycled.
return;
view.findViewById(R.id.imageLoading).setVisibility(
View.GONE);
view.findViewById(R.id.image)
.setVisibility(View.VISIBLE);
((ImageView) view.findViewById(R.id.image))
.setImageBitmap(image);
}}).execute();I'm thinking that a queue-based method would work better, but I'm wondering if there is one or if I should attempt to create my own implementation.
I have the following code...
CODE:.................
My mClient get method is a simple HttpClient execute with an output buffer to read the input stream, so it's very trivial. Everytime I execute this task UnknownHostException will be triggered which will in turn call onTaskError on my currect Activity, but I still get a RuntimeException, but I don't see why. Maybe it's because it's late and i've done about 12 hours of writing code so it's something simple I just can't see?
In my android application i am using a loading screen,processed by Async task.In do in background of this task i would like to display a alert whenever an upgraded version exist in the server.
Could you please let me know if there is any way that i can do it in android.
The code is.
CODE:.................
I am trying to get the GPS location of my HTC magic using the following code...
View 2 Replies View RelatedI have been searching for an answer for this for some time now. I have an async task that downloads the database needed for my app, while this is downloading my app cant do anything as all the data it references is in this file, i have the app waiting for the file to be downloaded but i am attempting to show a progress dialog so the user knows something is happening while they wait for this to happen.however nothing shows up i have also tried directly calling ProgressDialog.show in the pre execute and moving this to the calling activity with no luck.
View 2 Replies View RelatedI have a simple app and I'm using the AsyncTask to test out a background process, for clearness purposes I've opted to put my AsyncTask in a separate class rather than in an inner class, which where my problems begin, this is my AsyncTask. Code...
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View 2 Replies View RelatedI have google voice and use it for every phone call I make. I heard that there were issues with several gvoice updates, so I haven't updated google voice since 0.2.8 and it is working just fine- every call connects, no problems. Is it worth updating to the newest version of google voice with push? For those of you with 2.1 on your Eris- does google voice work for you?
View 12 Replies View RelatedI'm searching for android phones that can use video out to the tv for a research project. I'm considering the HTC Touch Pro.
Is there anything I have to do specifically to get the video out to work (for displaying my app on the tv)? or will the phone just display a running app on the tv without extra work?
I'm trying to determine whether or not my phone is defective, or if this is a current problem with the Cliq.
Of the apps I've downloaded, only a few of them have worked. Of those few that work, some don't work right. Has anyone had problems with these apps crashing on them, or just not working correctly?
- Nice Battery (see description at bottom of: My Ultimate CLIQ settings (so far))
- WeatherBug (kept showing the wrong location, crashed when trying to change location)
- Snake - doesn't work just says its "paused"
- RingDroid - crashes when I select the "Facebook Pop" button
- Layar - screen is rotated 90 degrees at all times
There have been others, but usually I just uninstall them right after discovering it doesn't work right.
I've had an HTC Desire on Orange in the UK for about 6 weeks and it is having persistent problem. Firstly despite having a strong 4-bar out of 4 signal, online services and the internet do not work at all when a 3G signal is being received (e.g. news, weather, all widgets, internet, email etc).Calls and texts do work however with a 3G signal.But when a 3g+ signal (HSDPA) is being received, all internet services as above work fine.However, when a 3+ signal is being received, the phone does not make or receive calls or text messages, and often fails to send texts. Calls I make immediately shut down (bleep + �call ended�), and incoming calls from other people go straight to answerphone. Also often when turning the data connection on/off, it freezes and has to be rebooted, and turning airplane setting on and off does not fix the problem.
I have also tried the different network settings (GSM, WCDMA, auto, etc). �GSM� sends and receives calls and texts but doesn�t work (or is incredibly slow) with internet, and �auto� and �WCDMA only� show the problems as above.I don't think this is a network/coverage issues as, as I have seen many people reporting these same issues on other networks and in other parts of the UK, and I have read that other people are having to manually turn off HSDPA to be able to make calls (using an app?). Even if I can stop HSDPA from connecting to make sure the phone works, I still can�t use the internet at all on 3g � even GSM works better!
Finally, when I connect to a bluetooth device (e.g. car and headphones) the phone will connect briefly, and then randomly disconnect. I have also seen this issue reported elsewhere.I very much like the phone and don't want to get rid of it, but these problems are making the phone unuseable.Also I don't know if I should be contacting HTC or Orange about this. Will the upcoming Android 2.2 fix these problems?Anyone know how to fix this or if I need a new handset? Are there any apps that can help? Also does the Nexus One have these problems and are they fixed by Froyo?
So I made a discovery - my dialpad doesn't work during a call. Even if I bring it up via the softkeys, the numbers don't register a tap...anyone. else have this issue or is it just my phone?
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