I'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?
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I have a file called nochart.png in /drawable.
How can I set this to an ImageView?
chartImageView.setImageDrawable(R.drawable.nochart);
Does not compile.
I have valid JPG files and now I want to load them into a layout containing an ImageView. I have code to findViewId(R.id.myimage). I followed some sample code using File but it did not work. The file is stored at /data/data/com.myapp/files/someimage.jpg.
What is the easiest and efficient way to load and display?
Like the title. I have a small drawable file, but the ImageView is much larger than it. How I can fill it without left any extra space?
View 1 Replies View RelatedThe following code executes a function that retrieves a file via ftp and then displays it in an imageview. Since I'm using the main thread the UI locks up, somebody tells me I can use asynctask to make this work but I can't figure it out :<
Is anybody familiar with this that could offer me some guidance? code...
In Reference to this android file download problem http://stackoverflow.com/questions/576513/android-download-binary-file-problems
Can anyone explain what does this line mean in the code FileOutputStream f = new FileOutputStream(new File(root,"Video.mp4")); And what does it mean by the parameter root within the File(). Do I need to specify the root path to save the file? if it is the case then how do we specify the root path in android. Code...
Is there a way to load an image file into an ImageView object, and then define a transparent color for this object?
View 1 Replies View RelatedIm 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?
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 RelatedWhat 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 have a listlayout with items in it that looks like this:
There is first an ImageView (the light) and then two textViews. All of this inside a TableLayout. (source here: http://code.google.com/p/switchctrl/source/browse/trunk/android/res/layout/device_switch.xml)
I want to have a rotating animation of a loading indicator Ontop of this light when this particular device (light) performs an action or an action is performed on it.
How do I put an animation ontop of this light imageview?
I 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...
View 8 Replies View RelatedI'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 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.
Can someone please tell me where I'm going wrong with this piece of code? Basically I want the app to download a .png file, display it to the user and also save it to the sd card for future reference. It seems to be all going fine until the while ((len = webstream.read(buffer)) > 0) part; as the debugger doesn't reach the breakpoint I've put in here, and I have a directory of empty .png files. I have the WRITE_EXTERNAL_STORAGE permission declared in my Manifest.......
View 2 Replies View RelatedI am having problems downloading a binary file (video) in my app from the internet. In Quicktime, If I download it directly it works fine but through my app somehow it get's messed up (even though they look exactly the same in a text editor).
View 4 Replies View RelatedI'm over in Canada and cannot download Beebplayer
I was wondering if anyone had the .apk file for it?
I want my app to catch downloads of a particular kind of file.
Here's the corresponding part of AndroidManifest.xml:
CODE:............
Now, open a page with a link to an .exe file, click it. The download manager starts and then tells that The content is not supported on the phone. My activity doesn't even get called.
The questions are:
1) Why doesn't my activity get called?
2) What's the correct way of letting download manager do it's job and then get notified upon file download completion?
How to download an xml file from url connection in android?
View 13 Replies View RelatedHow can we download a file from server using ftp? How can we use android's download manager manually to download ?
View 3 Replies View RelatedAnybody know where I can download sshadapter as an apk file? I have an m001 tablet and it cannot access the official Android Market.
View 2 Replies View RelatedDoes anyone have a good example of using a service to download a file?
I am not sure whether to use remote or local and even if I was sure, I need a basic example to start with.
Basically, I want to start the service with the url of the file to downland and when the download is done end the service.
Google's example of services is filled with junk so I am not sure what is needed and what is not.
I would like to a mimetype to Android Web browser, to allow opening my application when a certain mime type file is downloaded by the web browser. Apparently, only media file's mime type can be supported by the web browser. Is it right? How can I do it?
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