UICollectionView 集合视图 的使用

直接上代码：

//
//  RootViewController.m
//
//

#import "RootViewController.h"
#import "CollectionViewCell.h"


@interface RootViewController ()<UICollectionViewDataSource, UICollectionViewDelegate>

@property (nonatomic, retain) UICollectionView *collectionView ; // 集合视图


@end



@implementation RootViewController

- (void)dealloc {
    [_collectionView release];
    [super dealloc];
}

- (void)viewDidLoad {
    [super viewDidLoad];

    // 1、在创建集合视图对象之前须要创建集合视图的布局类对象，用于对集合视图的单元格做布局。

    UICollectionViewFlowLayout *flowLayout = [[[UICollectionViewFlowLayout alloc] init] autorelease];
    // 2、为相关属性
    // 设置最小行间距
    flowLayout.minimumLineSpacing = 5;
    // 设置最小列间距
    flowLayout.minimumInteritemSpacing = 5;
    // 设置 itemSize
    flowLayout.itemSize = CGSizeMake((CGRectGetWidth(self.view.bounds) - 40) / 4, 120);
    // 设置分区的内边距
    flowLayout.sectionInset = UIEdgeInsetsMake(5, 5, 5, 5);
    // 设置滑动方向,默认是纵向滑动。

//    flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
    // 指定页眉大小
    flowLayout.headerReferenceSize = CGSizeMake(200, 60);
    // 指定页脚大小
    flowLayout.footerReferenceSize = CGSizeMake(200, 40);

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

    // 须要制定代理对象
    self.collectionView.dataSource = self;
    self.collectionView.delegate = self;

    // 加入集合视图显示
    [self.view addSubview:self.collectionView];


    // 为集合视图注冊单元格类型
    [self.collectionView registerClass:[CollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
    // 为集合视图注冊页眉页脚的类型
    [self.collectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"header"];
    [self.collectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"footer"];


}

// 为集合视图的每个分区指定 item 的数量
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return 100;
}

// 为集合视图的每个 Item 指定相应的单元格
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
    cell.titleLable.text = [NSString stringWithFormat:@"(%ld, %ld)", indexPath.section, indexPath.item];
//    cell.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255.0 green:arc4random() % 256 / 255.0 blue:arc4random() % 256 / 255.0 alpha:1];
    return cell;
}

// 集合视图的页眉页脚视图使用的是 UICollectionReusableView 或其子类的对象，同一时候页眉页脚通过 kind 来区分。而且使用专门的重用机制。来完毕对页眉页脚视图的管理。
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
    if ([kind isEqualToString:UICollectionElementKindSectionHeader]) {
        UICollectionReusableView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"header" forIndexPath:indexPath];
        headerView.backgroundColor = [UIColor orangeColor];
        return headerView;
    }
    UICollectionReusableView *footerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"footer" forIndexPath:indexPath];
    footerView.backgroundColor = [UIColor redColor];
    return footerView;
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    UIViewController *viewController = [[UIViewController alloc] init];
    [self.navigationController pushViewController:viewController animated:YES];
    [viewController release];
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end

//
//  CollectionViewCell.h
//
//

#import <UIKit/UIKit.h>

@interface CollectionViewCell : UICollectionViewCell

@property (nonatomic, retain) UILabel *titleLable ; //


@end

//
//  CollectionViewCell.m
//
//

#import "CollectionViewCell.h"

@implementation CollectionViewCell

- (void)dealloc {
    [_titleLable release];
    [super dealloc];
}

- (UILabel *)titleLable {
    if (!_titleLable) {
        self.titleLable = [[[UILabel alloc] initWithFrame:self.bounds] autorelease];
        _titleLable.backgroundColor = [UIColor lightGrayColor];
        _titleLable.textColor = [UIColor whiteColor];
        _titleLable.font = [UIFont systemFontOfSize:16];
        _titleLable.textAlignment = NSTextAlignmentCenter;
        [self.contentView addSubview:_titleLable];
    }
    return _titleLable;
}

@end