Home/ Questions/Q 6071667
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-23T10:04:25+00:00

I display an UIImage in a view. Sometimes the requested image isn’t in the

  • 0

I display an UIImage in a view. Sometimes the requested image isn’t in the main bundle or in user folders.
If this is the case, I want to :

  1. start downloading the image from a remote server
  2. set a UIActivityIndicator on the target UIImageView
  3. after complete download, save the downloaded image in a folder
  4. load the UIImage in the UIImageView and stop the UIActivityIndicator

Dealing with the case where the user change the view while the download isn’t finished is hard. I do want the download to continue until the end. On the other end, he can go to another view lauching a parallel download.

I have created a DownloadManager with a static method +getImage:(NSString*)URL targetUIImageView:(UIImageView*)targetUIV
I want this method to instanciate new ImageDLClass with each it’s own ASIHTTPRequest, it’s own target (assign) UImageView. Testing if this target == nil permits to know if view is deallocated or not.

What I can’t figure out is, who will retain all the ImageDLClass instances, and how could I deallocate them after download finished.

I look for architecture ideas, I already know how to code each point. Do you have architecture ideas ?

Thanks for your help !

kheraud

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I finally use a better thing.

    The magick keyword here is “userInfo”. In fact you can link anything with a request and retreive this “anything” in the delegate methods.

    My architecture is the following :

    • A singleton ImageManager
    • ImageManager has one attribute : an array containing the request not finished yet
    • ImageManager has a method which launches an ASIHTTPRequest and add this request to its array
    • In the userInfo of each request there is a pointer to the target UIImageView
    • UIActivityIndicatorView is created (with 555 tag number) and added as subview to the target UIImageView after having started the asynchronous request
    • UIActivityIndicatorView is removed using its tag number

    The array attribute permits to cancel and release all non-finished requests if the ImageManager is deallocated.

    Hope it can help !

    kheraud

    • 0