Wie lade ich ein GIF-Bild in Swift?

//
// iOSDevCenters+GIF.swift
// GIF-Swift
//
// Created by iOSDevCenters on 11/12/15.
// Copyright © 2016 iOSDevCenters. All rights reserved.
//
import UIKit
import ImageIO


extension UIImage {

public class func gifImageWithData(data: NSData) -> UIImage? {
    guard let source = CGImageSourceCreateWithData(data, nil) else {
        print("image doesn't exist")
        return nil
    }

    return UIImage.animatedImageWithSource(source: source)
}

public class func gifImageWithURL(gifUrl:String) -> UIImage? {
    guard let bundleURL = NSURL(string: gifUrl)
        else {
            print("image named \"\(gifUrl)\" doesn't exist")
            return nil
    }
    guard let imageData = NSData(contentsOf: bundleURL as URL) else {
        print("image named \"\(gifUrl)\" into NSData")
        return nil
    }

    return gifImageWithData(data: imageData)
}

public class func gifImageWithName(name: String) -> UIImage? {
    guard let bundleURL = Bundle.main
        .url(forResource: name, withExtension: "gif") else {
            print("SwiftGif: This image named \"\(name)\" does not exist")
            return nil
    }

    guard let imageData = NSData(contentsOf: bundleURL) else {
        print("SwiftGif: Cannot turn image named \"\(name)\" into NSData")
        return nil
    }

    return gifImageWithData(data: imageData)
}

class func delayForImageAtIndex(index: Int, source: CGImageSource!) -> Double {
    var delay = 0.1

    let cfProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil)
    let gifProperties: CFDictionary = unsafeBitCast(CFDictionaryGetValue(cfProperties, Unmanaged.passUnretained(kCGImagePropertyGIFDictionary).toOpaque()), to: CFDictionary.self)

    var delayObject: AnyObject = unsafeBitCast(CFDictionaryGetValue(gifProperties, Unmanaged.passUnretained(kCGImagePropertyGIFUnclampedDelayTime).toOpaque()), to: AnyObject.self)

    if delayObject.doubleValue == 0 {
        delayObject = unsafeBitCast(CFDictionaryGetValue(gifProperties, Unmanaged.passUnretained(kCGImagePropertyGIFDelayTime).toOpaque()), to: AnyObject.self)
    }

    delay = delayObject as! Double

    if delay < 0.1 {
        delay = 0.1
    }

    return delay
}

class func gcdForPair(a: Int?, _ b: Int?) -> Int {
    var a = a
    var b = b
    if b == nil || a == nil {
        if b != nil {
            return b!
        } else if a != nil {
            return a!
        } else {
            return 0
        }
    }

    if a! < b! {
        let c = a!
        a = b!
        b = c
    }

    var rest: Int
    while true {
        rest = a! % b!

        if rest == 0 {
            return b!
        } else {
            a = b!
            b = rest
        }
    }
}

class func gcdForArray(array: Array<Int>) -> Int {
    if array.isEmpty {
        return 1
    }

    var gcd = array[0]

    for val in array {
        gcd = UIImage.gcdForPair(a: val, gcd)
    }

    return gcd
}

class func animatedImageWithSource(source: CGImageSource) -> UIImage? {
    let count = CGImageSourceGetCount(source)
    var images = [CGImage]()
    var delays = [Int]()

    for i in 0..<count {
        if let image = CGImageSourceCreateImageAtIndex(source, i, nil) {
            images.append(image)
        }

        let delaySeconds = UIImage.delayForImageAtIndex(index: Int(i), source: source)
        delays.append(Int(delaySeconds * 1000.0)) //Seconds to ms
    }

    let duration: Int = {
        var sum = 0

        for val: Int in delays {
            sum += val
        }

        return sum
    }()

    let gcd = gcdForArray(array: delays)
    var frames = [UIImage]()

    var frame: UIImage
    var frameCount: Int
    for i in 0..<count {
        frame = UIImage(cgImage: images[Int(i)])
        frameCount = Int(delays[Int(i)] / gcd)

        for _ in 0..<frameCount {
            frames.append(frame)
        }
    }

    let animation = UIImage.animatedImage(with: frames, duration: Double(duration) / 1000.0)

    return animation
}
}

Hier ist die Datei, die aktualisiert für Swift 3

InformationsquelleAutor der Antwort Zach Doster