【iOS】UIImageView播放gif动图

//解析gif文件数据的方法 block中会将解析的数据传递出来
-(void)getGifImageWithUrk:(NSURL *)url returnData:(void(^)(NSArray<UIImage *> * imageArray, NSArray<NSNumber *>*timeArray,CGFloat totalTime, NSArray<NSNumber *>* widths,NSArray<NSNumber *>* heights))dataBlock{
    //通过文件的url来将gif文件读取为图片数据引用
    CGImageSourceRef source = CGImageSourceCreateWithURL((CFURLRef)url, NULL);
    //获取gif文件里图片的个数
    size_t count = CGImageSourceGetCount(source);
    //定义一个变量记录gif播放一轮的时间
    float allTime=0;
    //存放全部图片
    NSMutableArray * imageArray = [[NSMutableArray alloc]init];
    //存放每一帧播放的时间
    NSMutableArray * timeArray = [[NSMutableArray alloc]init];
    //存放每张图片的宽度 （一般在一个gif文件里，全部图片尺寸都会一样）
    NSMutableArray * widthArray = [[NSMutableArray alloc]init];
    //存放每张图片的高度
    NSMutableArray * heightArray = [[NSMutableArray alloc]init];
    //遍历
    for (size_t i=0; i<count; i++) {
        CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
        [imageArray addObject:(__bridge UIImage *)(image)];
        CGImageRelease(image);
        //获取图片信息
        NSDictionary * info = (__bridge NSDictionary*)CGImageSourceCopyPropertiesAtIndex(source, i, NULL);
        CGFloat width = [[info objectForKey:(__bridge NSString *)kCGImagePropertyPixelWidth] floatValue];
        CGFloat height = [[info objectForKey:(__bridge NSString *)kCGImagePropertyPixelHeight] floatValue];
        [widthArray addObject:[NSNumber numberWithFloat:width]];
        [heightArray addObject:[NSNumber numberWithFloat:height]];
        NSDictionary * timeDic = [info objectForKey:(__bridge NSString *)kCGImagePropertyGIFDictionary];
        CGFloat time = [[timeDic objectForKey:(__bridge NSString *)kCGImagePropertyGIFDelayTime]floatValue];
        allTime+=time;
        [timeArray addObject:[NSNumber numberWithFloat:time]];
    }
    dataBlock(imageArray,timeArray,allTime,widthArray,heightArray);
}

//为UIImageView加入一个设置gif图内容的方法：
-(void)setGifImage:(NSURL *)imageUrl{
    __weak id __self = self;
    [self getGifImageWithUrk:imageUrl returnData:^(NSArray<UIImage *> *imageArray, NSArray<NSNumber *> *timeArray, CGFloat totalTime, NSArray<NSNumber *> *widths, NSArray<NSNumber *> *heights) {
        //加入帧动画
        CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"contents"];
        NSMutableArray * times = [[NSMutableArray alloc]init];
        float currentTime = 0;
        //设置每一帧的时间占比
        for (int i=0; i<imageArray.count; i++) {
            [times addObject:[NSNumber numberWithFloat:currentTime/totalTime]];
            currentTime+=[timeArray[i] floatValue];
        }
        [animation setKeyTimes:times];
        [animation setValues:imageArray];
        [animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];
        //设置循环
        animation.repeatCount= MAXFLOAT;
        //设置播放总时长
        animation.duration = totalTime;
        //Layer层加入
        [[(UIImageView *)__self layer]addAnimation:animation forKey:@"gifAnimation"];
    }];
}

直接调用setGifImage:imageurl就好