关于实现Image的动态图片的播放

最新推荐文章于 2024-08-25 12:12:39 发布

转载最新推荐文章于 2024-08-25 12:12:39 发布 · 443 阅读

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原文链接：https://my.oschina.net/u/2986115/blog/1581068

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#swift #python

本文介绍如何在Swift中实现动态GIF图的播放功能。通过继承UIImage并重写其方法，可以轻松地将GIF图加载到UIImageView中进行播放。文章提供了完整的代码示例，并解释了关键步骤。

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最近在写Swift的时候，需要有一个动态播放头像的功能，于是就自己试着写了个。

这个需要继承UIImage，重写它的方法，全部代码直接贴上去

// UIImageGIF.swift

// SwiftYiRen

// Created by 李文强 on 2017/11/1.

import UIKit

import ImageIO

extension UIImageView{

public func loadGif(name: String) {

DispatchQueue.global().async {

let image = UIImage.gif(name: name)

DispatchQueue.main.async {

self.image = image

}

extension UIImage {

public class func gif(data: Data) -> UIImage? {

// Create source from data

guard let source = CGImageSourceCreateWithData(data as CFData, nil) else {

print("SwiftGif: Source for the image does not exist")

return nil

}

return UIImage.animatedImageWithSource(source)

}

public class func gif(url: String) -> UIImage? {

guard let bundleURL = URL(string: url) else {

print("SwiftGif: This image named \"\(url)\" does not exist")

return nil

}

guard let imageData = try? Data(contentsOf: bundleURL) else {

print("SwiftGif: Cannot turn image named \"\(url)\" into NSData")

return nil

}

return gif(data: imageData)

}

public class func gif(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

}

// Validate data

guard let imageData = try? Data(contentsOf: bundleURL) else {

print("SwiftGif: Cannot turn image named \"\(name)\" into NSData")

return nil

}

return gif(data: imageData)

}

internal class func delayForImageAtIndex(_ index: Int, source: CGImageSource!) -> Double {

var delay = 0.1

let cfProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil)

let gifPropertiesPointer = UnsafeMutablePointer<UnsafeRawPointer?>.allocate(capacity: 0)

if CFDictionaryGetValueIfPresent(cfProperties, Unmanaged.passUnretained(kCGImagePropertyGIFDictionary).toOpaque(), gifPropertiesPointer) == false {

return delay

}

let gifProperties:CFDictionary = unsafeBitCast(gifPropertiesPointer.pointee, to: CFDictionary.self)

// Get delay time

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 ?? 0

if delay < 0.1 {

delay = 0.1 // Make sure they're not too fast

}

return delay

}

internal class func gcdForPair(_ a: Int?, _ b: Int?) -> Int {

var a = a

var b = b

// Check if one of them is nil

if b == nil || a == nil {

if b != nil {

return b!

} else if a != nil {

return a!

} else {

return 0

}

// Swap for modulo

if a! < b! {

let c = a

a = b

b = c

}

// Get greatest common divisor

var rest: Int

while true {

rest = a! % b!

if rest == 0 {

return b! // Found it

} else {

a = b

b = rest

}

internal class func gcdForArray(_ array: Array<Int>) -> Int {

if array.isEmpty {

return 1

}

var gcd = array[0]

for val in array {

gcd = UIImage.gcdForPair(val, gcd)

}

return gcd

}

internal class func animatedImageWithSource(_ source: CGImageSource) -> UIImage? {

let count = CGImageSourceGetCount(source)

var images = [CGImage]()

var delays = [Int]()

for i in 0..<count {

// 添加图片

if let image = CGImageSourceCreateImageAtIndex(source, i, nil) {

images.append(image)

}

let delaySeconds = UIImage.delayForImageAtIndex(Int(i),

source: source)

delays.append(Int(delaySeconds * 1000.0)) // Seconds to ms

}

// Calculate full duration

let duration: Int = {

var sum = 0

for val: Int in delays {

sum += val

}

return sum

}()

// Get frames

let gcd = gcdForArray(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

}

使用

//头像

var myHeaderImage:UIImageView = {

let image = UIImageView.init(frame: CGRect(x:0,y:0,width:80,height:80))

image.backgroundColor = UIColor.blue

image.layer.cornerRadius = 40

image.image = UIImage.gif(name:"GIF图片名（自己工程里的）")

image.layer.masksToBounds = true

return image

}()

转载于:https://my.oschina.net/u/2986115/blog/1581068