FHYWaterfallCollectionView

A WaterfallCollectionViewDemo 简便集成一个瀑布流图片效果的Demo 本来想做成一个控件，但看起来并没达成。 不过可以在50行左右代码集成出一个瀑布流效果图吧。 六部完成瀑布流。

第一步：引入申明文件

import "FHYWaterView.h"

第二步：遵循三个协议

@interface ViewController ()<UICollectionViewDataSource, UICollectionViewDelegate, EqualWidthLayOutDelegate>

第三步 初始化一个FHYWaterView

self.waterView = [[FHYWaterView alloc] initWaterViewWithFrame:self.view.bounds];
EqualWidthLayOut *layOut = (EqualWidthLayOut *)self.waterView.collectionViewLayout;
[layOut setDelegate:self];
[self.waterView setDelegate:self];
[self.waterView setDataSource:self];
[self.view addSubview:_waterView];

第四步：返回FHYWaterViewCell类型的Cell

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    FHYWaterViewModel *cellContent = self.contentArray[indexPath.row];
    FHYWaterViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:NSStringFromClass([FHYWaterViewCell class]) forIndexPath:indexPath];
    [cell setCellContent:cellContent];
    return cell;
}

第五步：从网络获取数据并转换成WaterView需要的Model

- (void)getDataFromNet{
    AFHTTPSessionManager *session = [AFHTTPSessionManager manager];
    [session GET:kTextUrlString parameters:nil progress:^(NSProgress * _Nonnull downloadProgress) {

    } success:^(NSURLSessionDataTask * _Nonnull task, id  _Nullable responseObject) {
    NSArray *dataArray = (NSArray *)responseObject;
    for (NSDictionary *dataDictionary in dataArray) {
    //获取到数据后初始化模型并添加到数组中
    NSString *imageUrl = [dataDictionary objectForKey:@"image_url"];
    CGFloat imageWidth = [[dataDictionary objectForKey:@"image_width"] floatValue];
    CGFloat imageHeight = [[dataDictionary objectForKey:@"image_height"] floatValue];
    FHYWaterViewModel *cellContent = [[FHYWaterViewModel alloc] initWithUrlString:imageUrl imageWidth:imageWidth andImageHeight:imageHeight];
    [self.contentArray addObject:cellContent];
    }
    [_waterView reloadData];
    } failure:^(NSURLSessionDataTask * _Nullable task, NSError * _Nonnull error) {
    NSLog(@"%@", kTextUrlString);
    }];
}

第六步：执行代理方法

- (CGFloat)collectionView:(UICollectionView *)view layout:(EqualWidthLayOut *)layout heightForItemAtIndexPath:(NSIndexPath *)indexPath{
    FHYWaterViewModel *dataModel = [self.contentArray objectAtIndex:indexPath.row];
    CGFloat kCellWidth = (kWidth - 10 * 3) / 2;
    return kCellWidth * ( dataModel.height / dataModel.width );
}