iOS开发中实现显示gif图片的方法

// //  SvGifView.h //  SvGifSample // //  Created by maple on 3/28/13. //  Copyright (c) 2013 smileEvday. All rights reserved. //

#import <UIKit/UIKit.h>

@interface SvGifView : UIView

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

- (void)startGif;

- (void)stopGif;

+ (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 <ImageIO/ImageIO.h> #import <QuartzCore/CoreAnimation.h>

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)]];         currentTime += [[_frameDelayTimes objectAtIndex:i] floatValue];     }     [animation seTKEyTimes:times];         NSMutableArray *images = [NSMutableArray arrayWithCapacity:3];     for (int i = 0; i < count; ++i) {         [images addObject:[_frames objectAtIndex:i]];     }         [animation setValues:images];     [animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];     animation.duration = _totalTime;     animation.delegate = self;     animation.repeatCount = 5;         [self.layer addAnimation:animation forKey:@"gifAnimation"]; }

- (void)stopGif {     [self.layer removeAllAnimations]; }

// remove contents when animation end - (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {     self.layer.contents = nil; }

// Only override drawRect: if you perfORM custom drawing. // An empty implementation adversely affects performance during animation. - (void)drawRect:(CGRect)rect {     // Drawing code }

@end

    // 设定位置和大小     CGRect frame = CGRectMake(50,50,0,0);     frame.size = [UIImage imageNamed:@"guzhang.gif"].size;     // 读取gif图片数据     NSData *gif = [NSData dataWithContentsOfFile: [[NSBundle mainBundle] pathForResource:@"guzhang" ofType:@"gif"]];     // view生成     UIWebView *webView = [[UIWebView alloc] initWithFrame:frame];     webView.userInteractionEnabled = NO;//用户不可交互     [webView loadData:gif MIMEType:@"image/gif" textEncodingName:nil baseURL:nil];     [self.view addSubview:webView];     [webView release];

 UIImageView *gifImageView = [[UIImageView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];     NSArray *gifArray = [NSArray arrayWithObjects:[UIImage imageNamed:@"1"],                                                   [UIImage imageNamed:@"2"],                                                   [UIImage imageNamed:@"3"],                                                   [UIImage imageNamed:@"4"],                                                   [UIImage imageNamed:@"5"],                                                   [UIImage imageNamed:@"6"],                                                   [UIImage imageNamed:@"7"],                                                   [UIImage imageNamed:@"8"],                                                   [UIImage imageNamed:@"9"],                                                   [UIImage imageNamed:@"10"],                                                   [UIImage imageNamed:@"11"],                                                   [UIImage imageNamed:@"12"],                                                   [UIImage imageNamed:@"13"],                                                   [UIImage imageNamed:@"14"],                                                   [UIImage imageNamed:@"15"],                                                   [UIImage imageNamed:@"16"],                                                   [UIImage imageNamed:@"17"],                                                   [UIImage imageNamed:@"18"],                                                   [UIImage imageNamed:@"19"],                                                   [UIImage imageNamed:@"20"],                                                   [UIImage imageNamed:@"21"],                                                   [UIImage imageNamed:@"22"],nil];     gifImageView.animationImages = gifArray; //动画图片数组     gifImageView.animationDuration = 5; //执行一次完整动画所需的时长     gifImageView.animationRepeatCount = 1;  //动画重复次数     [gifImageView startAnimating];     [self.view addSubview:gifImageView];     [gifImageView release];