设置图片进度条

[self.picImage sd_setImageWithURL:[NSURL URLWithString:self.model.pic] placeholderImage:PLACEPIC];
[self.picImage sd_setImageWithURL:[NSURL URLWithString:self.model.pic] placeholderImage:nil options:0 progress:^(NSInteger receivedSize, NSInteger expectedSize) {
self.progress.progress = (double)receivedSize / expectedSize;
} completed:^(UIImage *image, NSError *error, SDImageCacheType cacheType, NSURL *imageURL) {
[self.progress removeFromSuperview];
self.progress = nil;
}];