Caching and Loading local Images asynchronously in tableview - ios

Hi i am pretty new to IOS so pardon for silly questions . I am working on an app which loads large images in a tableview. Images to be loaded are of large size (>5MB) so i am trying to resize the image into thumbnails ,cache it and the load it asynchronously to table view. i found many ways and discussions for doing the same for network images (SDWebImages etc.) but i couldn't get anything for doing the same with local images (camera/photo library). Can any one tell me how to implement it?

You need to implement lazy loading of image along with asynchronous loading of images.
https://developer.apple.com/library/ios/samplecode/LazyTableImages/Introduction/Intro.html
https://github.com/rs/SDWebImage
http://iphonedevelopment.blogspot.in/2010/05/downloading-images-for-table-without.html

Related

How to use cache images for display in flutter until url is loading?

I am having a sample application which is having networking images, how to display preloaded cache images when navigating between pages. Because it is taking some time for loading from api calls. instead of placeholder how to display same image which loaded previously.
I am trying to use flutter_cache_manager 0.1.1, cached_network_image 0.4.1+1
plugins but still unable to achieve.
I think you are looking for FadeInImage where you can set a placeholder image until the actual image becomes available.
The actual image can come from various ImageProviders like NetworkImageWithRetry or similar.

Web image download vs Web image to display in imageview

In my application is like (Montage) to show a lot of images, videos , music and also to mainatain the image id for its own identification and other purpose. I need to know the whether the all image is show using sdwebimage in imageview or after i logged in all images to download and saved it to local files ? Tell me which is good ?
SDWebImage is already providing caching mechanism, so instead of downloading all images at once use SDWebImage
SDWebImage also using lazy load, so the performance of your application will be good.
But if you try to download all images at once, it will degrade your app performance. You need to wait before loading view till downloading end.

UICollectionview lags with local stored images

I have simple application, who consumes data from local core data storage. I am displaying images in collectionview & it lags when i scroll. All images are from local bundle itself.
Can anyone help?
Thanx.
Store all the images in an array once and use that array instead of fetching images from core data everytime the cell loads.
A typical solution to this would be to use the proxy design pattern and to load images asynchronously on a background thread.
You could have a UIImageView subclass that shows a placeholder image or a blank rectangle, but that is automatically updated once the image has been loaded. Some apps even use this to make a fancy "polaroid fade" effect, i.e. fade the image from white or black when it goes on-screen.
To prevent placeholder images from ever being seen (although you'd want to test this on device, as local storage might be fast enough to make this unnoticeable), you could pre-cache images in advance (for example by anticipating a number of extra rows in your cellForRowAtIndexPath method)

Is it possible to take an image from a UIWebView and display it natively without reloading?

Say I load a webpage with an image on it. Is there a way to reuse this loaded image within a UIImageView without reloading the image from a url?
If the image is cached by URL loading system, it will come from the cache when you try to load it.
Sorry I can't give a large explanation as im on y phone but I feel like what your looking for is 'core data store' there are several examples of how to use this framework, but it's quite complicated and has a large learning curve with ios development.
Also you say 'a' uiwebview. Does that mean that the URL your accessing to show within your uiwebview is static? If so, just copy and save the image and store the image in your project for future reference.
Or are you allowing the user to keep swapping through links in the uiwebview and store all those images that popup on the web page?
Sorry I'm just unclear with the question... Please no down votes :)

iOS: Best approach for image gallery [Image Caching]

I have to implement an Image Gallery for the iPhone iOS. Pictures are loaded from the web based on an XML document which contains the URLs of the pictures. My question is - what is the best approach for implementing an Image Gallery Overview of all pictures of a certain gallery? (where all pictures are presented to the user at once, like in a GridView. This question focuses on performance issues because one gallery can have more than 100 photos - each of them has a size of 100KB or more).
I already tried to implement a simple View which consists of multiple UIImageViews (rows and cols) where the images are loaded asynchronously. But the App crashes with low memory warnings, so I have to load the pictures on demand and not all at once.
What would be the best way to implement such a Gallery Overview? Using an UITableView with 3 pictures for each cell for instance? Or is it better to use a paged UIScrollView where the user is able to switch between pages where each page presents 12 pictures or so?
The main problem is the caching of the images. Would be glad for some hints.
You can cache images regardless on which solution you do, to cache the images you can either implement your own caching mechanism or use one already mad ( i opt for the second choice) i normally use ASIHTTPRequest, more specifically i use ASIDownloadCache check their documentation but its very easy to use

Resources