iOS|iOS 加载网络图片&瀑布流&cell高度自适应 iOS加载网络图片&瀑布流&cell高

【iOS|iOS 加载网络图片&瀑布流&cell高度自适应】写在前面吧：
现目前是这样的：有数量不等的图片需要瀑布流显示，每张图片高宽度各有不同
初步思路：根据上述问题需求，可知，使用表视图为最佳方式
关键: 图片高宽度不定，cell需要动态计算高度；图片需做缩放处理，适应屏幕
使用SDWebImage下载图片

思路就如上所述，具体代码如下：
1、计算cell高度(前提是已做好数据请求处理)

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{ // 先从缓存中查找图片 UIImage *image = [[SDImageCache sharedImageCache] imageFromDiskCacheForKey:self.sdwebArr[indexPath.row]]; if (!image) { image = [UIImage imageNamed:@"store_no_data"]; } //H = H*(SCREEN_WIDTH/W) = 高度*(屏幕/图片宽) CGFloat imageHeight = image.size.height * SCREEN_WIDTH/image.size.width; return imageHeight; }

2、cellForRowAtIndexPath(调用configureCell: atIndexPath:方法)

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{ ShopDetailCell *cell = [tableView dequeueReusableCellWithIdentifier:reuseIdentifier]; if (cell == nil) { cell = [[ShopDetailCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:reuseIdentifier]; } [self configureCell:cell atIndexPath:indexPath]; cell.selectionStyle = UITableViewCellSelectionStyleNone; return cell; }

3、调用(downloadImage: forIndexPath:)

- (void)configureCell:(ShopDetailCell *)cell atIndexPath:(NSIndexPath *)indexPath { NSString *imgURL = self.sdwebArr[indexPath.row]; UIImage *cachedImage = [[SDImageCache sharedImageCache]imageFromDiskCacheForKey:imgURL]; if (!cachedImage) { [self downloadImage:self.sdwebArr[indexPath.row] forIndexPath:indexPath]; }else{ [cell.imgBtn setBackgroundImage:cachedImage forState:UIControlStateNormal]; } }

4、下载对应图片、使用GCD回到主线程刷新UI

- (void)downloadImage:(NSString *)imageURL forIndexPath:(NSIndexPath *)indexPath { [[SDWebImageDownloader sharedDownloader] downloadImageWithURL:[NSURL URLWithString:imageURL] options:SDWebImageDownloaderUseNSURLCache progress:^(NSInteger receivedSize, NSInteger expectedSize, NSURL * _Nullable targetURL) { //nothing to do } completed:^(UIImage * _Nullable image, NSData * _Nullable data, NSError * _Nullable error, BOOL finished) { [[SDImageCache sharedImageCache] storeImage:image forKey:imageURL toDisk:YES completion:^{}]; dispatch_async(dispatch_get_main_queue(), ^{ [self.detailTableView reloadData]; }); }]; }