UICollectionView
#import "ViewController.h"
#define ID @"reuse"
#import "MyCollectionViewCell.h"
#import "MyCollectionReusableView.h"
#define kWidth self.view.frame.size.width
@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
@end
@implementation ViewController
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{
return CGSizeMake((kWidth - 40) / 3, 100);
}
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, 0, 0, 0);
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 20;
}
//- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
// return 20;
//}
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section {
//
//}
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section {
//
//}
- (void)viewDidLoad {
[super viewDidLoad];
//创建一个布局对象,采用系统布局类UICollectionViewFlowLayout
UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
// //设置最小的行间距
// layout.minimumLineSpacing = 10;
//
// //设置Item之间间距
// layout.minimumInteritemSpacing = 10;
// //设置集合视图的分区间隔
// layout.sectionInset = UIEdgeInsetsMake(10, 10, 10, 10);
//设置集合视图的滑动方向
layout.scrollDirection = UICollectionViewScrollDirectionVertical;
CGFloat totalWidth = self.view.frame.size.width;
//设置每一个Item的尺寸大小
// layout.itemSize = CGSizeMake((totalWidth - 40) / 3, 80);
layout.headerReferenceSize = CGSizeMake(totalWidth, 40);
//集合视图的创建必须指定布局,如果没有布局,显示不了任何东西
UICollectionView *collectionView = [[UICollectionView alloc] initWithFrame:[UIScreen mainScreen].bounds collectionViewLayout:layout];
//集合视图如果想要显示内容,必须将cell注册
[collectionView registerClass:[MyCollectionViewCell class] forCellWithReuseIdentifier:ID];
collectionView.dataSource = self;
collectionView.delegate = self;
//如果想要分区头视图显示,必须注册增广视图
[collectionView registerClass:[MyCollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"header"];
[self.view addSubview:collectionView];
collectionView.backgroundColor = [UIColor grayColor];
// Do any additional setup after loading the view, typically from a nib.
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return 60;
}
// The cell that is returned must be retrieved from a call to -dequeueReusableCellWithReuseIdentifier:forIndexPath:
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
// static NSString *ID = @"reuse";
MyCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:ID forIndexPath:indexPath];
cell.contentView.backgroundColor = [UIColor colorWithRed:arc4random() % 256 / 255.0 green:arc4random() % 256 / 255.0 blue:arc4random() % 256 / 255.0 alpha:1.0];
cell.numberLabel.text = [NSString stringWithFormat:@"道无涯第%ld步",indexPath.row + 1];
return cell;
}
//设置分区个数
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 3;
}
//返回增广视图,也就是集合视图的头视图或者尾视图
- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
MyCollectionReusableView *view = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"header" forIndexPath:indexPath];
view.backgroundColor = [UIColor blueColor];
view.headerLabel.text = [NSString stringWithFormat:@"仙逆第%ld部 ",indexPath.section + 1];
return view;
}
#pragma mark -----集合视图代理方法----
//Item点击之后触发的方法
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(@"%ld %ld",indexPath.section,indexPath.row);
}
#import "MyCollectionViewCell.h"
@implementation MyCollectionViewCell
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
//获取整体Item的宽和高
CGFloat totalWidth = frame.size.width;
CGFloat totalHeight = frame.size.height;
self.numberLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 10, totalWidth, totalHeight - 20)];
self.numberLabel.textAlignment = NSTextAlignmentCenter;
self.numberLabel.font = [UIFont boldSystemFontOfSize:14];
[self.contentView addSubview:self.numberLabel];
}
return self;
}
@end
#import "MyCollectionReusableView.h"
@implementation MyCollectionReusableView
- (instancetype)initWithFrame:(CGRect)frame {
self = [super initWithFrame:frame];
if (self) {
self.headerLabel = [[UILabel alloc] initWithFrame:self.bounds];
self.headerLabel.textAlignment = NSTextAlignmentCenter;
self.headerLabel.font = [UIFont boldSystemFontOfSize:36];
[self addSubview:self.headerLabel];
}
return self;
}
@end