UICollectionView 集合视图

#import "RootViewController.h"

#import "DetailViewController.h"

static NSString *string = @"cell";

static NSString *headerIndetifier = @"header";

static NSString *footerIndetifier = @"footer";

@interface RootViewController ()<UICollectionViewDataSource, UICollectionViewDelegate>

@end

@implementation RootViewController

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view.

self.view.backgroundColor = [UIColor yellowColor];

self.navigationItem.title = @"集合视图";

//UICollectionView,集合视图, UITableView的好基友,与他十分相似

//UICollectionView,继承于UIScrollView

//UICollectionViewLayout,集合视图的布局.继承于NSObject,控制和管理集合视图的布局,是抽象基类,不能直接使用

//UICollectionViewFlowLayout,UICollectionViewLayout的子类,可以使用

UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];

//cell的大小

flowLayout.itemSize = CGSizeMake(50, 50);

//cell在X轴上的间距,默认10

flowLayout.minimumInteritemSpacing = 10;

//cell在Y轴上的间距,默认10

flowLayout.minimumLineSpacing = 10;

//滚动方向,默认垂直滚动

flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;//垂直滚动

//分区间距

flowLayout.sectionInset = UIEdgeInsetsMake(50, 20, 50, 20);//上左下右

//区头大小

flowLayout.headerReferenceSize = CGSizeMake(375, 50);

//区尾大小

flowLayout.footerReferenceSize = CGSizeMake(375, 50);

UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:self.view.bounds collectionViewLayout:flowLayout];

collectionView.backgroundColor = [UIColor whiteColor];

collectionView.dataSource = self;//设置数据源

collectionView.delegate = self;//设置代理

//注册cell类型

[collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:string];

//注册区头类型

[collectionView registerClass:[UICollectionViewCell class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:headerIndetifier];

//注册区尾类型

[collectionView registerClass:[UICollectionViewCell class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:footerIndetifier];

[self.view addSubview:collectionView];

[collectionView release];

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

#pragma mark - UICollectionViewDataSource

//某个分区有多少个cell(单元格)

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {

return 100;

}

//展现cell

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {

//UICollectionViewCell,集合视图单元格,继承于UICollectionReusableView

UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:string forIndexPath:indexPath];

//随机颜色

cell.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255. green:arc4random() % 256 / 255. blue:arc4random() % 256 / 255. alpha:1.000];

return cell;

}

//分区个数

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {

return 2;

}

//创建附加视图(区头和区尾)

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {

//根据kind判断是区头或区尾

if ([kind isEqualToString:UICollectionElementKindSectionHeader]) {

//区头

UICollectionReusableView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:headerIndetifier forIndexPath:indexPath];

headerView.backgroundColor = [UIColor colorWithRed:0.272 green:1.000 blue:0.725 alpha:1.000];

return headerView;

}else {

//区尾

UICollectionReusableView *footerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:footerIndetifier forIndexPath:indexPath];

footerView.backgroundColor = [UIColor colorWithRed:0.738 green:0.970 blue:1.000 alpha:1.000];

return footerView;

}

}

#pragma mark - UICollectionViewDelegate

//点击了某一个cell

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {

NSLog(@"点击了:%ld--%ld", indexPath.section, indexPath.item);

DetailViewController *detailVC = [[DetailViewController alloc] init];

detailVC.color = collectionView.backgroundColor;

[self.navigationController pushViewController:detailVC animated:YES];

[detailVC release];

}

@end