How many Views are possible in a view flipper in android? - android

I am developing an application in android in which i want to show about 170 images, but i want user can view images by finger either right or left . After searching from internet i got a solution, therefore i had use View flipper in my application It will work when the counting of images are 15, when the counting increasing above fifteen it will crash.
Can you tell me the reason for this or is there a limitation in view flipper that we cannot show more than 15 views.
Give me any suggession for solve my problem.
Thanks in advance!

I suggest you to use Gallery (Gallery tutorial), ViewFlipper will load complete view in memory, so when you load more images it will take more memory and there is good chance for OutOfMemoryError.
For displaying Images Gallery is the best choice

The view flipper has not such limitations. Probably the issue is that you're loading in memory all those images. Try to avoid to have more than 2 or 3 images in memory at any given time or you'll run out of RAM

Related

Out of memory exception on inflating layouts

I am getting random out of memory exceptions in my app caused by inflate exceptions.
I have 7 fragment (difficulty) activities which launch their own activities via buttons. Each fragment has a scroll view with 30 buttons (levels).
I have set it up so that i can swipe across to each fragment and the fragment takes up the entire screen.
Occasionally when i swipe a few times and then select a random button from a group of 30 it will crash. It tries to load the activity and gives an out of memory exception with an inflate exception on a random line. The line always falls on an imageView or imageButton in the xml file. The activities that load are a grid of imageViews and imageButtons.
I do not get the exception much but it is something i want to fix. I have looked at many other out of memory exception questions although none have helped me. I have done a Memory analyser test and it shows nothing out of the ordinary.
I believe that the imageViews and imageButtons are using too much memory, although i only ever have one activity open at once.
It IS because of your images that are loading. When you load an image and you move around the page and view another image the heap increases. As you continue the process of viewing random images the heap grows even more until your app crashes. It's like stacking books on a glass table. You either move(cache) a book(image) or the glass(app) breaks. You should use an imageloader to load your images.
https://github.com/nostra13/Android-Universal-Image-Loader
You've mentioned that it always falls on an ImageView and ImageButton - and this is the clue to solve this problem. You get OOM 'cause background resource of this view has high resolution and takes a lot of memory. Try to lower resolution of this image.
Also you've mentioned that you have a ScrollView and this means that you keep in memory every 30 items. Probably you'd better change it to RecyclerView backed by adapter.
Just had the same problem and I'd like to simplify all the things said here:
Simply: reduce your images sizes.
Don't use 1080X1920 images... It's too high res.
Such image, even if compressed, when deployed will catch about 1080X1920X4B = 8.2MB (The GPU has to deploy it to it's full original resolution... That's why compression won't help but reducing the needed memory size...) and this i RAM that we're talking about..
Take Gimp or Photoshop and down scale the image to, say, 1/4: 540X960, and you won't feel the difference.. Belive me, been there already.
Beware of the memory consumption of images and videos.
Hope this helps,
James

How to use listview to render huge images?

I have a huge image to render (1024x25373p) cut into 99 images of 1024x256p.
I have tried to use a ListView, but without success : it crashes when scrolling, whithout any error (exept one line saying the proccess was stopped).
So, my question is, how do I render this huge image ?
Please note that I have tried to use TileView by moagrius, without success (I can't get it to work with navigation drawer)
As a suggestion ,
If this is listview, you may not need such larger size images "1024x256p" .
Actual size of your imageView may much for less than that. So its a wastage of
heap if you try to load those images directly without some processing.
Definitly you need to do some scaling down for your image based on actual size that you need. Nice exapmple and code has been published on the official doc
You need to deallocate memory or clear the all bitmaps which are not visible on the listview for particular moment.
You can use progressing loader in order to load your images in to the listview. Then loading will be happen based on the scrolling.
Also you can define lager heap enable in your manifest though it is not recommended but has to do in highly memory consumable apps.
android:largeHeap="true"

Is it bad to set images by drawable ID or through xml

I have a large amount of image views to load ( background and 80 other images). Some are buttons and some are small 10 by 10 Imageviews. Some of the images (like 20% are referring to the same image)
Right now I just load them through xml or through the code by providing resource ID. Am I doing it wrong? Should I perhaps load them all into Bitmaps first in the memory and then set them to the View? Or maybe do the "downsampling" thing.
Please let me know if what I am doing is wrong. I am worried about Out of memory issues
Thanks
Its not bad to set background and some images with xml or resource id code. To do a lot of them this way is not good.
Try looking around for third party gallery libraries to help you out. I would also recommend reading about viewpagers which holds a configurable number of pages in memory and recreates others on the fly, helping manage memory usage.
http://www.androidbegin.com/tutorial/android-viewpager-gallery-images-and-texts-tutorial/

How to cope with jitter when using Android-Universal-Image-Loader in a ListView?

I'm using Android-Universal-Image-Loader in a ListView of mine and I'm trying to find the best solution to following:
using resetViewBeforeLoading is necessary or else I get the same image in my ConvertViews, but this causes jitter, unless..
I use PauseOnScrollListener which is otherwise great, except that it shows a blank in some ConvertViews even for images that are already downloaded (I'm using memory and disk caches), so it's confusing to the user who sees a blank for an image they saw only 2 swipes ago
So it seems that I can't get an instant image load (for already-downloaded images) on scroll without jitter, even for images in memory, is this about right? Is there a better or more standard way to do this? (Vertical list-view showing screen-width images, sort of like the Instagram app, which does it buttery-smooth)
Otherwise, is there a way to lengthen the number of convertViews in my ListView to prevent unnecessarily aggressive re-use?
Thanks in advance

Managing Memory for showing large bitmaps in android

I know this question is asked several times, but still clarity to my situation would be helpful.
I am showing some images in 2 column grid view. When user taps on an image, I am displaying the image in ViewPager. The Image which is displayed in gridview is about 200X200px and I want to show the same image with enlarged size say about 800X800px in ViewPager in a DialogFragment.
The Actual size of images are huge with different resolutions. I have followed the link http://developer.android.com/training/displaying-bitmaps/index.html and I have scaled down images to size which is required for my app. In ViewPager fragment dialog I am also recycling the image with bitmap.recycle() and calling System.gc() explicitly(I know this is a bad practice) at PagerFragment onDestroy. But even then I am getting Out of memory error. On top of it, I am encountering this issue only in Android 4.2.1 (Nexus 7) but not on Android 4.1.2( Samsung Tab) and Android 4.4(Nexus 7).
For later 2 android versions, I do not have to call even System.gc(). It works very well without this. I have checked Viewpager with some 300 - 400 images. But for former after scrolling 60 images, App is crashing with OutOfmemory error. To resolve this I have used a workaround for now android:largeHeap="true" which I think is very bad for myapp and could not digest it.
I really appreciate if anyone who can help me avoid android:largeHeap="true".
In my app, I have to show around 6000 images in GridView and also an enlarged image in ViewPager linked to GridView. I am loading only 20 images from FileSystem asynchronously while scrolling gridview.
Thanks in advance...
Use an LRUCache to hold the images. Make that the only thing that holds a Bitmap that's not currently on screen. That way the older bitmaps will be kicked out and garbage collected quickly.

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