I am having a real hard time understanding how to embed many images and sounds in an iPhone app. When I say embed, I mean I want the images and sounds to be downloaded with the app, and some of those images will appear when the app is run. Other images are just saved in the app's disk space, so that when a user presses a button, the image or sound will be accessed and displayed or played.
I have read tutorials on using 'core data' and such, but that only seems like a way to create objects that can be used to reference such data items, or for storing small files as binary data. Can someone please tell me how in xcode I can specify a directory of images and .mp3s to be loaded onto a phone with my app, and how I can then call those media with code?
Some example code for the following would completely solve my problem:
An app is loaded onto a phone, and it contains 3 buttons. If the user presses button #1, a sound is heard. Button #2 plays a different sound, and button #3 changes a UIImageView to a different picture. (this isn't a homework assignment or something, but if I could code this example, I could do everything I need to in my app and understand the process)
Thanks!
I mean I want the images and sounds to be downloaded with the app
Simply add the images and sounds to your project. Make sure you specify (in the Add Files to Project dialog) that they are to copied into the project and that they are to be part of the target. The result will be that the images and sounds will be built into your app (in what is called its bundle, in particular the main bundle - see the NSBundle docs). You can then fetch them out, as needed, in code. For example, to fetch an image, use imageNamed:. To refer to a sound, refer to the file as a resource within the main bundle.
Other images are just saved in the app's disk space
That is a completely different matter. You will have to get the images from somewhere while the app runs. There is no way to have the user download the app and the image end up in the app's disk space: the app must populate its disk space, in real time, as the app runs. At the time the user downloads the app, the associated disk space, outside the app bundle itself, will be empty.
For images, see the responses to this question.
Sound is similar to images, but is loaded differently, this tutorial show how to load and play sounds.
For files that are saved after the app is installed, you will need to download and save those files in your code. For starters, see Apple's guide to the iOS file system
Related
In my app user will have a list of items, each item will have a thumbnail,the thumbnails are downloaded from the net, so i want to save the images in the app directory, so that the app won't download thumbnails every time, now i am saving images in NSLibraryDirectory, and there are many directories available like NSDocumentDirectory,NSApplicationSupportDirectory.. those images will be downloaded if they are not present in the NSLibraryDirectory.My question is which directory is the correct place to save these thumbnail images so the user need not download the images every time. Previously i used NSDocumentLibrary but i have read that those will be backed up by iCloud and apple could reject the app for that. So, i have changed to NSLibraryDirectory and everything is working fine. Is it okay to do so. Any better way to store images like that.Thank you
Here is all about this:
https://developer.apple.com/library/ios/documentation/FileManagement/Conceptual/FileSystemProgrammingGuide/FileSystemOverview/FileSystemOverview.html
I prefer to store thumbnails in temporary directory which system clears automatically. I also wrote class which is responsible for cache files in directory you set.
http://github.com/tomkowz/TSFileCache
it's downloading and retrieve images memory waste. better use: https://github.com/nicklockwood/AsyncImageView
my app has been rejected due to iCloud Storage Restrictions. (2.23).
There are lots of questions for this situation, but i am still not sure why my app has been rejected.. Here are my suspects:
1- My app downloads pdf files and images for letting users see on "offline" mode when a user selects a row from a tableview. I've set my download folder as "Documents/privateDownloads" and set the folder (and files inside) url flags as "do not backup"
2- My app also has a 2Mb. "preload.json" file, which my app reads the file at first launch and preloads into the database only at first launch (with a progress hud showing the progress of importing data). I haven't set the "preload.json" file as "do not backup".I just drag dropped the file into "Supporting Files" group in Xcode.
My guess is the problem lies in the 2nd suspect, but i've also read that i should move the "privateDownloads" folder into "Application Support" Folder instead of Documents folder.
i always stored my offline files on nsurl cache for a very long time (technically forever), but this time i've decided to do like this.
thanks for reading and helping.
Edit: there is a note from app store for rejection reason:
"In particular, we found that on launch and/or content download, your
app stores 3.6MB"
When i control this issue, this is happening after my application "preloads" the data. But what i really don't get it is, i am storing this preloaded data in core data. So yes, i want this data to be backed up in iCloud?!
To solve the issue of your seed data being too large, you might split your Core Data stack in two separate stores - one which stores the user data and is backed up to iCloud. And a second one which stores the seeded data imported from your JSON. This store could then be excluded from iCloud backup via the "do not backup"-flags.
Another recommended way would be to ship a pre-populated store like described in this article on objc.io. Since you mentioned your preload.json is several MB, this would be even more desirable to pre-generate the store once than on every device on initial app startup. And you could apply the required file attributes for not backing it up more easily.
The issue won't have anything to do with your preload.json file. If that's included in your app distribution, it is part of the app and you don't need to do anything different with it.
I would suspect that the reviewer didn't notice you were setting the 'do not backup' flag on files you've added to the Documents/privateDownloads folder, or that you have a bug and the flag isn't being set at all. It is safer, if you're able, to store those kinds of files in a /Library/Caches sub directory. Then you don't need to worry about the flag.
I have a question regarding how to update local images embedded as content in the application.
My application is built using 30 images stored as "Content" (embedded in the app) for a image gallery that I have to show. Every 2 days the application check server info to see if the images have been changed in the database, in that case then I have to compare files and if any file has changed then I have to download it and update the local image.
I have read the the best way to store images for this kind of porposses is under "Library" folder of the application, but the images that comes with the app are built as "Content" (embedded)...
Any clue on the best way to do that in monotouch?
Thanks.
Resources, like images, that you bundle inside your .app becomes part of your application. Since the application is signed you cannot update (or remove) those files as it would invalidate the signature (there's also file permissions that won't allow this to happen).
note: it can work in the iOS simulator since it does not require (or check) for application signatures, however it won't works for application on devices.
What you can do is:
Bundle default images with your applications;
Download new images (when needed) and install them outside your application (in the appropriate directory);
Have your application checks if there are downloaded images (or if images needs to be downloaded) and fallback to the images that ships with your application;
You can't change any file from your app (they're read-only).
What you can do is to save the files to a read-write directory, and at runtime check if those images are there (and not then use the ones bundled with the app).
I am working on a Vegetable gardening application. Apart from the vegetable name and description I also have vegetable image. Currently, I have all the images in the Supported Files folder in the Xcode project.
But later on I want to update the application dynamically without having the user download a new version. When the user updates the application or downloads new data from the server that data will include the images. Can I store those images in the supporting file folder or somewhere where they can be references by just the name.
RELATED QUESTION:
I will also allow the user to take pictures of their vegetables and then write notes about the vegetables like "just planted", "about to harvest" etc. What is the recommended approach for storing pictures/photos. I can always store them in the user's photo library and then store the reference in the local database and then fetch and display the picture using the reference. The problem with that approach might be that if the user accidentally deletes the picture from the library then it will no longer be displayed in my application.
The only way I see if to store the picture in the app local database as a BLOB.
No you can't put the downloaded images with the others inside the supporting file folder. Also I would suggest you put the images inside an Images or Resources folder instead... If you want to download any data after the app is compiled, then they will not be in the bundle. It is the bundle you are referring to when talking about the Supported Files folder in Xcode. This is read only for your application.
Just to be clear, once compiled, there are no folder structures for your application, these "folders" are just groups in the Xcode project to keep things tidy.
If you download say a zip file containing a set of images, it's up to you to write them to disk after you download them. You should put these images in either the tmp, the cache or the documents directory.
But then you'll have to build your path before loading the images. You won't be able to just provide the name of the file such as:
[UIImage imageNamed:#"something.jpg"];
Because this will look in your bundle. Instead you must do something like this to load your image from the Documents directory for example.
Your challenge is that you will end up in a state where you'll have some images in the Bundle (the ones from when you uploaded your app), and the newer ones in the documents directory. You must them check the bundle first and if there is no image there, check the documents directory.
For user generated data, I suggest also saving the images in the Documents directory, and maintaining an SQLite database of the users data, so you can map an image name to an entry in the database. You don't want to save the images as BLOB because this will inevitably slow down the performance of your queries and add extra unnecessary load on the CPU to convert to UIImage and back.
You don't want to save their images to the gallery for 2 reasons, first this means you'll be saving in 2 places because keeping a reference in your database to an external image is very fragile and you're just asking for trouble, and secondly, once the image isn't under your wing, you don't control it anymore, the user will delete it at some point, if they go back to your app they expect to see it there.
I am making an iPad application (iOS 5.0/5.1 with ARC and storyboard) for which I need to download an image or sound file from my server and then use it as background for all the screens of my application. I was thinking of keeping a placeholder image/audio file bundled within my application which I will refer to within the storyboard. Then when I get the file from the server, I can replace that image with the one coming from the server. However, I'm not sure if this can be done based on the directories that the app has access to.
Pls let me know if you can direct me whether it's possible to go down this road? and if yes, then which directory should I be downloading the image files to?
Thanks in advance for your help