Currently I want to make a list like pictures and images on the server when I click on it, it will download the images to the memory device. If the image is downloaded, it will not download again and the image that is not there will be downloaded. Then I want to ask for a solution from everyone, how should I handle the download to be clean and good for performance. Or do you have an example for me to refer to? Thank you!
There are some ways to find out if your image already exists in your phone storage but the best way to find it out is by image name, compare image names before downloading.
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When i develop a android app with download and caching image from internet, i see many app use MemoryLruCache or DiskLruCache to cache image after download. But i want to know why they use them, why don't use the way like: download image, then save image into sd card and after get image from sd card to show it( it is manual way).
I'm newbie in android dev. So please help me to understand it?
Thanks many many times.
well downloading a list of images from url will consume time and also fill up the user memory also....so its better to dynamically load images from url and make its cache and then preview the images from cache..
I hope you did got my point....check some example of lazy loading of image
I am using .net web services and I am having list of folders and files. I am successful in retrieving list of files(.jpg Image, .pdf, .TIF) but can anybody let me know how we can open .jpg, .pdf, .tif or other files format which I am getting from web services. Is there any specific code to open particular format or we can use path (/) to open that particular file?
Thanks.
if you need to download and display an image, check my answer on this post, that is probably what you are looking for. Common extensions for displaying images in Android are .png and .jpeg, you will not be able to show a .pdf file using an ImageView. You can also use the method mentioned in my answer inside an AsyncTask to perform the download in background and then update your UI thread
i've got a question about best solution for caching downloaded images. From internet are downloaded URLs of images i want to show with specifig tag. On some other activities will be showed previews of images and after click on preview will be shown image in full size and his description. My idea is save info about image to database with path to directory named after tag in cache directory. When preview should be shown, i look to cache and if there image is, good and if not image will be downloaded
Maybe use a naming convention so you won't need to use the database ?
Like this :
Profil picture for user 1 will be in
tmp/mypackage/pic_cache/user_pic_1.jpg
I am displaying image's from web using Image downloading logic from url, I want to image download at first time only, next time onwards don't download image from web, because First time downloaded image store in cache memory so i display image from cache memory, In case does not exits that image in cache memory, will download otherwise don't need download that image from web , How is it possible any body guide me ho to so this.?
Thanks in advance.
Go with the solution Lazy loading list with images because it does the same trick that you require. i.e. download image once, store it in cache and display as and when it requires.
go thorugh this example given at GitHub: https://github.com/thest1/LazyList
store your images in sdcard.check wheather your images exist in sdcard or not if yes simply display those images otherwise download from web and store in sdcard,display from sdcard
Can someone please point me in the right direction. I have been googling for ages and I'm not getting great results.
I want my app to allow the user to download a file from the USB/SDcard. Specifically an image, which then later gets used in my app.
I can't seem to find anything, been searching for open file dialogs and nothing..
So:
1) User inserts USB device/SDCard.
2) User gets file browser dialog.
3) User finds image from USB/SDCard
4) App grabs image and stores it for later use.
Thanks :)
I think what you are looking for is how to work with external storage in Android. there is a very good tutorial from android site: http://developer.android.com/guide/topics/data/data-storage.html#filesExternal. hope this helps.
To browse for images on the SDCard this thread is very helpful:
How to pick an image from gallery (SD Card) for my app?
I would suggest using the Android Gallery interface for images as it is much easier for the user than browsing files.