iOS GIF图片转UIImage

多平台保持统一风格的UI设计，少不了一些动态图片的使用

1、本地GIF图片使用

1.1 将本地GIF转为NSdata类型

  NSData *tempdata = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"networkLoading" ofType:@"gif"]];
  UIImageView *imgView = [[UIImageView alloc] initWithImage:[self decodeGifImageByData:tempdata]];

1.2 通过自定义方法处理GIF的data数据

 //解压gif的data为图片数组
 -(UIImage *)decodeGifImageByData:(NSData *)data {
     //获取data资源器，这个可以直接操作图片data
     CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, nil);
     //获取图片数量 size_t 类似于无符号int
     size_t count = CGImageSourceGetCount(source);
     UIImage * animationImage;

     //如果只有一张则直接解压
     if (count <= ) {
         animationImage = [[UIImage alloc]initWithData:data];
     }
     else {
         NSMutableArray * imageArray = [NSMutableArray arrayWithCapacity:count];
         NSTimeInterval duration = 0.0f;
         //遍历获取每一张图片
         for (size_t i = ; i < count; i++) {
             //解析图片拿到图片画笔拿到图片画笔
             CGImageRef imageRef = CGImageSourceCreateImageAtIndex(source, i, NULL);
             duration += [self imageDurationAtIndex:i source:source];
             //scale:图片缩放因子 默认1  orientation:图片绘制方向 默认网上
             [imageArray addObject:[UIImage imageWithCGImage:imageRef scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp]];
             CGImageRelease(imageRef);
         }

         //如果没有抓取到图片播放时间，则按照0.1秒一张的方式来了播放
         if (!duration) {
             duration = (1.0f / 10.0f) * count;
         }
         animationImage = [UIImage animatedImageWithImages:imageArray duration:duration];
     }

     CFRelease(source);
     return animationImage;
 }

 //获取每一张图片的持续时间
 -(float)imageDurationAtIndex:(NSUInteger)index source:(CGImageSourceRef)source {
     float imageDuration = 0.1f;
     //获取指定图像的属性信息 如宽、高、持续时间等都在里面 详情参考 CGImageProperties
     CFDictionaryRef cfImageProperties = CGImageSourceCopyPropertiesAtIndex(source, index, nil);
     if (!cfImageProperties) {
         return imageDuration;
     }
     NSDictionary * imageProperties = (__bridge NSDictionary *) cfImageProperties;
     //拿到gif图的属性信息 获取每一帧的时间
     NSDictionary * gifProperties = [imageProperties valueForKey:(NSString *)kCGImagePropertyGIFDictionary];
     NSNumber * delayTime = [gifProperties valueForKey:(NSString *)kCGImagePropertyGIFUnclampedDelayTime];
     if (delayTime != nil) {
         return delayTime.floatValue;
     }

     return imageDuration;
 }