水平方向瀑布流

 

效果

 

源码

////  GridFlowLayoutViewController.m//  Animations////  Created by YouXianMing on 16/5/5.//  Copyright © 2016年 YouXianMing. All rights reserved.//#import "GridFlowLayoutViewController.h"#import "UIView+SetRect.h"#import "GridLayout.h"#import "FlowStyleCell.h"#import "FileManager.h"#import "NSString+MD5.h"#import "NSData+JSONData.h"#import "ResponseData.h"#import "Math.h"#import "GCD.h"static NSString *picturesSource = @"http://www.duitang.com/album/1733789/masn/p/0/50/";@interface GridFlowLayoutViewController () 
     
      @property (nonatomic, strong) UICollectionView  *collectionView;@property (nonatomic)         CGFloat            rowHeight;@property (nonatomic, strong) NSMutableArray    *datas;@property (nonatomic, strong) ResponseData      *picturesData;@property (nonatomic, strong) NSMutableArray    
      
        *dataSource;@end@implementation GridFlowLayoutViewController- (void)setup {        [super setup];        _dataSource = [NSMutableArray new];        // 初始化布局文件    CGFloat gap               = 1;    NSInteger rowCount        = arc4random() % 3 + 2;    _rowHeight                = (self.contentView.height - (rowCount + 1) * gap) / (CGFloat)rowCount;    GridLayout *layout        = [GridLayout new];    layout.manager.edgeInsets = UIEdgeInsetsMake(gap, gap, gap, gap);    layout.manager.gap        = gap;    layout.delegate           = self;        NSMutableArray *rowHeights = [NSMutableArray array];    for (int i = 0; i < rowCount; i++) {                [rowHeights addObject:@(_rowHeight)];    }    layout.manager.rowHeights = rowHeights;        self.collectionView                                = [[UICollectionView alloc] initWithFrame:self.contentView.bounds                                                                            collectionViewLayout:layout];    self.collectionView.delegate                       = self;    self.collectionView.dataSource                     = self;    self.collectionView.backgroundColor                = [UIColor clearColor];    self.collectionView.showsHorizontalScrollIndicator = NO;    self.collectionView.alpha                          = 0;    [self.collectionView registerClass:[FlowStyleCell class] forCellWithReuseIdentifier:@"FlowStyleCell"];    [self.contentView addSubview:self.collectionView];        // 获取数据    [GCDQueue executeInGlobalQueue:^{                NSString *string       = [picturesSource lowerMD532BitString];        NSString *realFilePath = [FileManager theRealFilePath:[NSString stringWithFormat:@"~/Documents/%@", string]];        NSData   *data         = nil;                if ([FileManager fileExistWithRealFilePath:realFilePath] == NO) {                        data = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:picturesSource]];            [data writeToFile:realFilePath atomically:YES];                    } else {                        data = [NSData dataWithContentsOfFile:realFilePath];        }                NSDictionary *dataDic = [data toListProperty];                [GCDQueue executeInMainQueue:^{                        self.picturesData = [[ResponseData alloc] initWithDictionary:dataDic];            if (self.picturesData.success.integerValue == 1) {                                for (int i = 0; i < self.picturesData.data.blogs.count; i++) {                                        [_dataSource addObject:self.picturesData.data.blogs[i]];                }                                [_collectionView reloadData];                [UIView animateWithDuration:0.5f animations:^{                                        _collectionView.alpha = 1.f;                }];            }        }];    }];}- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {        return self.dataSource.count;}- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {        WaterfallPictureModel *pictureModel = _dataSource[indexPath.row];        FlowStyleCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"FlowStyleCell" forIndexPath:indexPath];    cell.indexPath      = indexPath;    cell.data           = pictureModel;    cell.rowHeight      = _rowHeight;    [cell loadContent];        return cell;}- (CGFloat)itemWidthWithIndexPath:(NSIndexPath *)indexPath {        WaterfallPictureModel *pictureModel = _dataSource[indexPath.row];        return  [Math resetFromSize:CGSizeMake(pictureModel.iwd.floatValue, pictureModel.iht.floatValue)                withFixedHeight:_rowHeight].width;}@end
      
     

 

细节

继承UICollectionViewLayout

重载UICollectionViewLayout的四个方法

部分实现细节