sdwebimage淡入淡出

__weaktypeof(cell) weakCell= cell;

[cell.specialPerformanceProductImageViewsd_setImageWithURL:[NSURLURLWithString:[productImageUrlEncodedURLString]]placeholderImage:[UIImageimageNamed:@"default_liebiao"]options:SDWebImageRetryFailed|SDWebImageLowPrioritycompleted:^(UIImage*image,NSError*error,SDImageCacheTypecacheType,NSURL*imageURL)

{

if(image && cacheType ==SDImageCacheTypeNone)

{

weakCell.specialPerformanceProductImageView.alpha=0.0f;

[UIViewanimateWithDuration:1.0animations:^{

weakCell.specialPerformanceProductImageView.alpha=1.0f;

}];

}else

{

weakCell.specialPerformanceProductImageView.alpha=1.0f;

}

}];

//改成到库里面的方案

https://segmentfault.com/q/1010000007486755【经验证 向上滑 还有点问题。要多加判断。】