Gif with uiwebview swift

Question

I've made a UIWebView to show a gif and i have 2 buttons login and register.

First of all when I run it my ram uses 270mb then if I click to a button goes to another viewcontroller (270mb stays) then if I go back it's like it's loading another gif and the ram goes up to 430mb.

I have already test the webview.stoploading() when button clicked

 override func viewDidLoad() {
    super.viewDidLoad()
let filePath = NSBundle.mainBundle().pathForResource("railway", ofType: "gif")
    let gif = NSData(contentsOfFile: filePath!)
    webview.loadData(gif!, MIMEType: "image/gif", textEncodingName: String(), baseURL: NSURL())
    webview.userInteractionEnabled = false; }



    @IBAction func login(sender: AnyObject) {

    webview.stopLoading()
}

UIWebView has memory leaks. Switching to WKWebView might solve your problems. For more info look: stackoverflow.com/questions/28401650/memory-leak-with-uiwebview and here also: nshipster.com/wkwebkit — Andrej

Alessandro Ornano Alessandro Ornano · Accepted Answer · 2016-05-17T07:54:26

Try to load your contents by using cache policy:

enum NSURLRequestCachePolicy : UInt {
    case UseProtocolCachePolicy
    case ReloadIgnoringLocalCacheData
    case ReloadIgnoringLocalAndRemoteCacheData
    static var ReloadIgnoringCacheData: NSURLRequestCachePolicy { get }
    case ReturnCacheDataElseLoad
    case ReturnCacheDataDontLoad
    case ReloadRevalidatingCacheData }

So your code can be:

let filePath = NSBundle.mainBundle().pathForResource("railway", ofType: "gif")
var requestURL = NSURL(string:filePath!);
var request = NSMutableURLRequest(URL: requestURL!,
            cachePolicy: .ReturnCacheDataElseLoad,
            timeoutInterval: 15.0)

webview.loadRequest(request)

You can also handle the NSURLCache memory :

override func viewDidLoad() {
    super.viewDidLoad()

    let cacheSizeMemory = 8*1024*1024; // 8MB
    let cacheSizeDisk = 32*1024*1024; // 32MB

    let sharedCache = NSURLCache.init(
        memoryCapacity:cacheSizeMemory,
        diskCapacity:cacheSizeDisk,
        diskPath: "nsurlcache"
    )

    NSURLCache.setSharedURLCache(sharedCache)
}

override func didReceiveMemoryWarning() {
    print("Received memory warning")

    NSURLCache.sharedURLCache().removeAllCachedResponses()

    super.didReceiveMemoryWarning()
}

Another thing you can do with your project is to cache your object with a code like this:

let cache = NSCache()
let myGiantObject: GiantObjectClass

if let cachedVersion = cache.objectForKey("GiantObjectClassCached") as? GiantObjectClass {
    // use the cached version
    myGiantObject = cachedVersion
} else {
    // create it from the original constructors then store in the cache
    myGiantObject = GiantObjectClass()
    cache.setObject(myObject, forKey: "GiantObjectClassCached")
}

Gif with uiwebview swift

2 Answers