Gif动态图UIImage

#pragma mark 动态图生成
-(UIImage *)getAnimatedGIFWithData:(NSString *)path
{
    NSData *data = [NSData dataWithContentsOfFile:path];
    if (!data)
    {
        return nil;
    }
    
    CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
    
    size_t count = CGImageSourceGetCount(source);
    
    UIImage *animatedImage;
    
    if (count <= 1)
    {
        animatedImage = [[UIImage alloc] initWithData:data];
    }
    else
    {
        NSMutableArray *images = [NSMutableArray array];
        
        NSTimeInterval duration = 0.0f;
        
        for (size_t i = 0; i < count; i++)
        {
            CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
            
            duration += [self frameDurationAtIndex:i source:source];
            
            [images addObject:[UIImage imageWithCGImage:image scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp]];
            
            CGImageRelease(image);
        }
        
        if (!duration)
        {
            duration = (1.0f/10.0f)*count;
        }
        
        animatedImage = [UIImage animatedImageWithImages:images duration:duration];
    }
    
    CFRelease(source);
    
    return animatedImage;
}
-(float)frameDurationAtIndex:(NSUInteger)index source:(CGImageSourceRef)source
{
    float frameDuration = 0.1f;
    CFDictionaryRef cfFrameProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil);
    NSDictionary *frameProperties = (__bridge NSDictionary *)cfFrameProperties;
    NSDictionary *gifProperties = frameProperties[(NSString *)kCGImagePropertyGIFDictionary];
    
    NSNumber *delayTimeUnclampedProp = gifProperties[(NSString *)kCGImagePropertyGIFUnclampedDelayTime];
    if (delayTimeUnclampedProp)
    {
        frameDuration = [delayTimeUnclampedProp floatValue];
    }
    else
    {
        
        NSNumber *delayTimeProp = gifProperties[(NSString *)kCGImagePropertyGIFDelayTime];
        if (delayTimeProp)
        {
            frameDuration = [delayTimeProp floatValue];
        }
    }
    
    // Many annoying ads specify a 0 duration to make an image flash as quickly as possible.
    // We follow Firefox's behavior and use a duration of 100 ms for any frames that specify
    // a duration of <= 10 ms. See <rdar://problem/7689300> and <http://webkit.org/b/36082>
    // for more information.
    
    if (frameDuration < 0.011f)
    {
        frameDuration = 0.100f;
    }
    
    CFRelease(cfFrameProperties);
    return frameDuration;
}