本文将带你了解IOS开发入门iOS开发中实现显示gif图片教程，希望本文对大家学IOS有所帮助。

          我们知道Gif是由一阵阵画面组成的，而且每一帧画面播放的时常可能会不相等，观察上面两个例子，发现他们都没有对Gif中每一帧的显示时常做处理，这样的结果就是整个Gif中每一帧画面都是以固定的速度向前播放，很显然这并不总会符合需求。

于是自己写一个解析Gif的工具类，解决每一帧画面并遵循每一帧所对应的显示时间进行播放。

程序的思路如下：

1、首先使用ImageIO库中的CGImageSource家在Gif文件。

2、通过CGImageSource获取到Gif文件中的总的帧数，以及每一帧的显示时间。

3、通过CAKeyframeAnimation来完成Gif动画的播放。

下面直接上我写的解析和播放Gif的工具类的代码：

//

//   SvGifView.h

//   SvGifSample

//

// Created   by maple on 3/28/13.

//   Copyright (c) 2013 smileEvday. All rights   reserved.

//

#import

@interface SvGifView : UIView

/*

*   @brief desingated initializer

*/

-   (id)initWithCenter:(CGPoint)center   fileURL:(NSURL*)fileURL;

/*

*   @brief start Gif Animation

*/

-   (void)startGif;

/*

*   @brief stop Gif Animation

*/

-   (void)stopGif;

/*

*   @brief get frames image(CGImageRef) in Gif

*/

+   (NSArray*)framesInGif:(NSURL*)fileURL;

@end

//

//   SvGifView.m

//   SvGifSample

//

//   Created by maple on 3/28/13.

//   Copyright (c) 2013 smileEvday. All rights   reserved.

//

#import "SvGifView.h"

#import

#import

/*

*   @brief resolving gif information

*/

void getFrameInfo(CFURLRef url, NSMutableArray *frames,   NSMutableArray *delayTimes, CGFloat *totalTime,CGFloat *gifWidth, CGFloat   *gifHeight)

{

CGImageSourceRef   gifSource = CGImageSourceCreateWithURL(url,   NULL);

// get frame   count

size_t frameCount =   CGImageSourceGetCount(gifSource);

for (size_t i = 0; i   < frameCount; ++i) {

//   get each frame

CGImageRef   frame = CGImageSourceCreateImageAtIndex(gifSource, i,   NULL);

[frames addObject:(id)frame];

CGImageRelease(frame);

// get gif info with each   frame

NSDictionary   *dict = (NSDictionary*)CGImageSourceCopyPropertiesAtIndex(gifSource, i,   NULL);

NSLog(@"kCGImagePropertyGIFDictionary   %@", [dict   valueForKey:(NSString*)kCGImagePropertyGIFDictionary]);

// get gif   size

if   (gifWidth != NULL &&   gifHeight != NULL) {

*gifWidth = [[dict   valueForKey:(NSString*)kCGImagePropertyPixelWidth]   floatValue];

*gifHeight = [[dict   valueForKey:(NSString*)kCGImagePropertyPixelHeight]   floatValue];

}

//   kCGImagePropertyGIFDictionary中kCGImagePropertyGIFDelayTime，kCGImagePropertyGIFUnclampedDelayTime值是一样的

NSDictionary   *gifDict = [dict   valueForKey:(NSString*)kCGImagePropertyGIFDictionary];

[delayTimes   addObject:[gifDict valueForKey:(NSString*)kCGImagePropertyGIFDelayTime]];

if (totalTime) {

*totalTime = *totalTime + [[gifDict   valueForKey:(NSString*)kCGImagePropertyGIFDelayTime]   floatValue];

}

}

}

@interface SvGifView() {

NSMutableArray *_frames;

NSMutableArray   *_frameDelayTimes;

CGFloat _totalTime; // seconds

CGFloat _width;

CGFloat _height;

}

@end

@implementation SvGifView

- (id)initWithCenter:(CGPoint)center   fileURL:(NSURL*)fileURL;

{

self   = [super   initWithFrame:CGRectZero];

if (self) {

_frames = [[NSMutableArray alloc]   init];

_frameDelayTimes = [[NSMutableArray alloc]   init];

_width =   0;

_height =   0;

if   (fileURL)   {

getFrameInfo((CFURLRef)fileURL, _frames, _frameDelayTimes,   &_totalTime, &_width,   &_height);

}

self.frame = CGRectMake(0,   0, _width,   _height);

self.center =   center;

}

return self;

}

+   (NSArray*)framesInGif:(NSURL *)fileURL

{

NSMutableArray *frames = [NSMutableArray   arrayWithCapacity:3];

NSMutableArray *delays = [NSMutableArray   arrayWithCapacity:3];

getFrameInfo((CFURLRef)fileURL, frames, delays, NULL, NULL,   NULL);

return frames;

}

-   (void)startGif

{

CAKeyframeAnimation *animation = [CAKeyframeAnimation   animationWithKeyPath:@"contents"];

NSMutableArray   *times = [NSMutableArray arrayWithCapacity:3];

CGFloat currentTime = 0;

int count =   _frameDelayTimes.count;

for (int i   = 0; i < count; ++i)   {

[times   addObject:[NSNumber numberWithFloat:(currentTime /   _totalTime)]];

<div class="l    

本文由职坐标整理并发布，希望对同学们有所帮助。了解更多详情请关注职坐标移动开发之IOS频道！