iOS实现水平方向瀑布流

//// 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 () <UICollectionViewDataSource, UICollectionViewDelegate, GridLayoutDelegate>@property (nonatomic, strong) UICollectionView *collectionView;@property (nonatomic)   CGFloat   rowHeight;@property (nonatomic, strong) NSMutableArray *datas;@property (nonatomic, strong) ResponseData  *picturesData;@property (nonatomic, strong) NSMutableArray <WaterfallPictureModel *> *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