MG--Swift—如何加载本地和网络的GIF图片

作者: Mg明明就是你 | 来源:发表于2016-08-29 16:58 被阅读1661次

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前言：
- 加载网络的GIF图片有很多框架，如：SDWebImage，AFN等。可是如何加载本地GIF，你可以用webView加载，当然用webView加载本地GIF没有问题，比如UBer的启动界面，你就可以尝试用这种方式。这里说的是另一种方式加载本地的GIF，具体如何请看代码：

0、运行效果图：

运行效果图.gif

1、MGGIFView

//  MGGifView.swift
//  MGGIFView
//  Created by ming on 16/8/29.
//  Copyright © 2016年 ming. All rights reserved.

/// 功能： 如何占展示一张本地的GIF图片
/// 功能： 如何占展示一张本地的GIF图片
/// 功能： 如何占展示一张本地的GIF图片

import UIKit
import ImageIO
import QuartzCore

class MGGifView: UIView {

    var width:CGFloat{return self.frame.size.width}
    var height:CGFloat{return self.frame.size.height}
    private var gifurl:NSURL! // 把本地图片转化成URL
    private var imageArr:Array<CGImage> = [] // 图片数组(存放每一帧的图片)
    private var timeArr:Array<NSNumber> = [] // 时间数组(存放每一帧的图片的时间)
    private var totalTime:Float = 0 // gif动画时间
    /**
    *  加载本地GIF图片
    */
    func showGIFImageWithLocalName(name:String) {
        gifurl = NSBundle.mainBundle().URLForResource(name, withExtension: "gif")
        self.creatKeyFrame()
    }

    
    /**
    *  获取GIF图片的每一帧 有关的东西  比如：每一帧的图片、每一帧的图片执行的时间
    */
    private func creatKeyFrame() {
        let url:CFURLRef = gifurl as CFURLRef
        let gifSource = CGImageSourceCreateWithURL(url, nil)
        let imageCount = CGImageSourceGetCount(gifSource!)
        
        for i in 0..<imageCount {
            let imageRef = CGImageSourceCreateImageAtIndex(gifSource!, i, nil) // 取得每一帧的图片
            imageArr.append(imageRef!)
            

            let sourceDict = CGImageSourceCopyPropertiesAtIndex(gifSource!, i, nil) as NSDictionary!
            let gifDict = sourceDict[String(kCGImagePropertyGIFDictionary)]
            let time = gifDict![String(kCGImagePropertyGIFUnclampedDelayTime)] as! NSNumber// 每一帧的动画时间
            timeArr.append(time)
            totalTime += time.floatValue
            
            // 获取图片的尺寸 (适应)
            let imageWitdh = sourceDict[String(kCGImagePropertyPixelWidth)] as! NSNumber
            let imageHeight = sourceDict[String(kCGImagePropertyPixelHeight)] as! NSNumber
            if ((imageWitdh.floatValue)/(imageHeight.floatValue) != Float((width)/(height))) {
                self.fitScale(imageWitdh: CGFloat(imageWitdh.floatValue), imageHeight: CGFloat(imageHeight.floatValue))
            }
        }
        
        self.showAnimation()
    }
    
    /**
    *  (适应)
    */
    private func fitScale(imageWitdh imageWitdh:CGFloat, imageHeight:CGFloat) {
        var newWidth:CGFloat
        var newHeight:CGFloat
        if imageWitdh/imageHeight > width/height {
            newWidth = width
            newHeight = width/(imageWitdh/imageHeight)
        } else {
            newWidth = height/(imageHeight/imageWitdh)
            newHeight = height;
        }
        let point = self.center;
        self.frame.size = CGSizeMake(newWidth, newHeight);
        self.center = point;
    }
    
    /**
    *  展示动画
    */
    private func showAnimation() {
        let animation = CAKeyframeAnimation(keyPath: "contents")
        var current:Float = 0
        var timeKeys:Array<NSNumber> = []
        
        for time in timeArr {
            timeKeys.append(NSNumber(float: current/totalTime))
            current += time.floatValue
        }
        animation.keyTimes = timeKeys
        animation.values = imageArr
        animation.repeatCount = HUGE;
        animation.duration = NSTimeInterval(totalTime)
        animation.removedOnCompletion = false
        self.layer .addAnimation(animation, forKey: "MGGifView")
    }
}

2、在控制器中调用

//
//  ViewController.swift
//  MGGIFView
//
//  Created by ming on 16/8/29.
//  Copyright © 2016年 ming. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 加载本地GIF 的View
        let gifView = MGGifView()
        gifView.frame = CGRectMake(0, 100, self.view.frame.width, 400)
        gifView.showGIFImageWithLocalName("gifDemo")
        view.addSubview(gifView)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
}```
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- #二、加载网络GIF图片
>#0、运行效果图：
![](https://img.haomeiwen.com/i117715/4e1c00e6c6ec95f9.gif?imageMogr2/auto-orient/strip)
![运行效果图.gif](https://img.haomeiwen.com/i1429890/4bd3ab70fe9b6555.png?imageMogr2/auto-orient/strip%7CimageView2/2/w/1240)

> - ###MGGIFView

// MARK: - 加载网络GIF图片
/**
* 加载网络GIF图片WebService
*/
func showGIFImageWithWebNetWorkUrl(url:NSURL) {
let fileName = self.getMD5StringFromString(url.absoluteString)
// 路径
let filePath = ("MGGifView/" + fileName + ".gif").doc()

    let manager = NSFileManager.defaultManager()
    if manager.fileExistsAtPath(filePath) {  // 本地读取
        self.gifurl = NSURL(fileURLWithPath: filePath)
        self.creatKeyFrame()
    }else { // 下载
        dispatch_sync(dispatch_get_global_queue(0, 0), { () -> Void in
            let session = NSURLSession.sharedSession()
            
            let task = session.dataTaskWithURL(url) { (data, response, error) -> Void in
                print(error)
                dispatch_async(dispatch_get_main_queue(), { () -> Void in
                    data?.writeToFile(filePath, atomically: true)
                    self.gifurl = NSURL(fileURLWithPath: filePath)
                    self.creatKeyFrame()
                })
            }
             task.resume()
        })
       
    }
}

/**
*  string -> MD5
*/
private func getMD5StringFromString(string:String) -> String {
    // 获取string
    let str = string.cStringUsingEncoding(NSUTF8StringEncoding)
    // 获取string 的长度
    let strlen = CC_LONG(string.lengthOfBytesUsingEncoding(NSUTF8StringEncoding))
    let digeTlen = Int(CC_MD5_DIGEST_LENGTH) // 强砖
    let result = UnsafeMutablePointer<CUnsignedChar>.alloc(digeTlen)
    CC_MD5(str!,strlen,result)
    
    // 创建一个可变的字符串
    let hash = NSMutableString()
    for i in 0..<digeTlen {
        hash.appendFormat("%02x",result[i])
    }
    result.destroy()
    
    return String(format: hash as String)
}

// MARK: - 清除缓存
/**
*  清除缓存方法
*/
func cleanCache() {
    let folderPath = ("MGGifView/").doc()
    let manager = NSFileManager.defaultManager()
    
    do{
        // fileName是一个文件夹数组
        let fileName = try? manager.contentsOfDirectoryAtPath(folderPath)
        for name in fileName! {
            try? manager.removeItemAtPath(folderPath+name)
        }
    }catch {
        
    }
}

***

> ###外部调用

import UIKit

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    
    // 加载本地GIF 的View
    let gifView = MGGifView()
    gifView.frame = CGRectMake(0, 0, self.view.frame.width, self.view.frame.height)

// gifView.showGIFImageWithLocalName("gifDemo")

    // 网址: https://img.haomeiwen.com/i117715/bbfe427d32237101.gif?imageMogr2/auto-orient/strip
    gifView.showGIFImageWithWebNetWorkUrl(NSURL(string:"https://img.haomeiwen.com/i117715/4e1c00e6c6ec95f9.gif?imageMogr2/auto-orient/strip")!)
    view.addSubview(gifView)
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}

}

***

> ###存储的分类（String）

import UIKit

extension String
{
func cache() -> String{
let cachePath = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.CachesDirectory, NSSearchPathDomainMask.UserDomainMask, true).last!
return (cachePath as NSString).stringByAppendingPathComponent((self as NSString).pathComponents.last!)
}

func doc() -> String{
    let documentPath = NSSearchPathForDirectoriesInDomains(NSSearchPathDirectory.DocumentDirectory, NSSearchPathDomainMask.UserDomainMask, true).last!
    return (documentPath as NSString).stringByAppendingPathComponent((self as NSString).pathComponents
    .last!)
}

func temp() -> String{
    let tempPath = NSTemporaryDirectory()
    return (tempPath as NSString).stringByAppendingPathComponent((self as NSString).pathComponents
        .last!)
}

}```