IOS UICollectionView学习

效果如下：

h文件代码

@interface MyCollectionViewCell : UICollectionViewCell

@property(nonatomic ,strong)UIButton *bgViewButton;
@property(nonatomic ,strong)UIImageView *imgView;
@property(nonatomic ,strong)UILabel *text;

@end

m文件代码

#import "HCollectionViewController.h"

@implementation MyCollectionViewCell


- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self)
    {
        self.backgroundColor = [HUtil colorWithHexString:@"dfdfdf"];
        
        self.bgViewButton = [[UIButton alloc] initWithFrame:CGRectMake(0.5, 0, CGRectGetWidth(self.frame)-0.5, CGRectGetWidth(self.frame)-0.5)];
        self.bgViewButton.backgroundColor = [UIColor whiteColor];
        
        self.imgView = [[UIImageView alloc] initWithFrame:CGRectMake(CGRectGetWidth(self.frame)/2-16, CGRectGetHeight(self.frame)/2-32, 32, 32)];
        self.imgView.backgroundColor = [UIColor clearColor];
        [self.bgViewButton addSubview:self.imgView];
        //        [self.bgViewButton addTarget:self action:@selector(cellButtonClicked:) forControlEvents:UIControlEventTouchUpInside];
        [self.bgViewButton addTarget:self action:@selector(changeBackGroundColor:) forControlEvents:UIControlEventTouchDown];
        [self.bgViewButton addTarget:self action:@selector(returnBackGroundColor:) forControlEvents:UIControlEventTouchDragExit];
        [self addSubview:self.bgViewButton];
        
        self.text = [[UILabel alloc]initWithFrame:CGRectMake(5, CGRectGetMaxY(self.imgView.frame)+10, CGRectGetWidth(self.frame)-10, 14)];
        self.text.backgroundColor = [UIColor clearColor];
        self.text.textAlignment = NSTextAlignmentCenter;
        [self.text setFont:[UIFont systemFontOfSize:14]];
        [self.text setTextColor:[HUtil colorWithHexString:@"252525"]];
        [self addSubview:self.text];
        
    }
    return self;
}

- (void)returnBackGroundColor:(id)sender
{
    self.bgViewButton.backgroundColor = [CHUtil colorWithHexString:@"ffffff"];
}

- (void)changeBackGroundColor:(id)sender
{
    self.bgViewButton.backgroundColor = [CHUtil colorWithHexString:@"efefef"];
}

@end



#import "HCollectionViewController.h"

#define UISCREENHEIGHT  self.view.bounds.size.height
#define UISCREENWIDTH  self.view.bounds.size.width
#define SCROLLVIEWHEIGHT (iPhone6Plus?210:140)

@interface HCollectionViewController ()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
{
    UICollectionView *mainCollectionView;
}

@end

@implementation CHCollectionViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor whiteColor];
    
    [self initCollectionView];
    
}

- (void)initCollectionView
{
    //1.初始化layout
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    //设置collectionView滚动方向
    [layout setScrollDirection:UICollectionViewScrollDirectionVertical]; //UICollectionViewScrollDirectionVertical  UICollectionViewScrollDirectionHorizontal
    //设置headerView的尺寸大小
    // layout.headerReferenceSize = CGSizeMake(self.view.frame.size.width, 100);
    //该方法也可以设置itemSize
    // layout.itemSize =CGSizeMake(110, 150);
    
    layout.minimumInteritemSpacing = 0;
    layout.minimumLineSpacing = 0;
    
    //2.初始化collectionView
    mainCollectionView = [[UICollectionView alloc] initWithFrame:CGRectMake(0, 64, self.view.bounds.size.width, self.view.bounds.size.height) collectionViewLayout:layout];
    [self.view addSubview:mainCollectionView];
    mainCollectionView.backgroundColor = [UIColor clearColor];
    
    //3.注册collectionViewCell
    //注意，此处的ReuseIdentifier 必须和 cellForItemAtIndexPath 方法中 一致 均为 cellId
    [mainCollectionView registerClass:[MyCollectionViewCell class] forCellWithReuseIdentifier:@"cellId"];
    
    //注册headerView  此处的ReuseIdentifier 必须和 cellForItemAtIndexPath 方法中 一致  均为reusableView
    // [mainCollectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"reusableView"];
    
    //4.设置代理
    mainCollectionView.delegate = self;
    mainCollectionView.dataSource = self;

}


#pragma mark -- UICollectionViewDataSource
//返回section个数
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 1;
}

//每个section的item个数
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return 9;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    
    MyCollectionViewCell *cell = (MyCollectionViewCell *)[collectionView dequeueReusableCellWithReuseIdentifier:@"cellId" forIndexPath:indexPath];
    
    cell.text.text = [NSString stringWithFormat:@"{%ld,%ld}",(long)indexPath.section,(long)indexPath.row];
    cell.imgView.image = [UIImage imageNamed:@"fabu_"];
    //cell.backgroundColor = [UIColor yellowColor];
    
    return cell;
}

//设置每个item的尺寸
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(kDEVICEWIDTH/3.0, kDEVICEWIDTH/3.0);
}

//footer的size
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section
//{
//    return CGSizeMake(10, 10);
//}

//header的size
//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section
//{
//    return CGSizeMake(10, 10);
//}

//设置每个item的UIEdgeInsets
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
    return UIEdgeInsetsMake(0, 0, 0, 0);
}

//设置每个item水平间距
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
    return 0;
}


//设置每个item垂直间距
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section
{
    return 0;
}


//通过设置SupplementaryViewOfKind 来设置头部或者底部的view，其中 ReuseIdentifier 的值必须和 注册是填写的一致，本例都为 “reusableView”
/*- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
    UICollectionReusableView *headerView = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"reusableView" forIndexPath:indexPath];
    headerView.backgroundColor =[UIColor grayColor];
    UILabel *label = [[UILabel alloc] initWithFrame:headerView.bounds];
    label.text = @"这是collectionView的头部";
    label.font = [UIFont systemFontOfSize:20];
    [headerView addSubview:label];
    return headerView;
}*/

#pragma mark -- UICollectionViewDelegate
//返回这个UICollectionView是否可以被选择
-(BOOL)collectionView:(UICollectionView *)collectionView shouldSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    return YES;
}

//点击item方法
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    MyCollectionViewCell *cell = (MyCollectionViewCell *)[collectionView cellForItemAtIndexPath:indexPath];
    NSString *msg = cell.text.text;
    NSLog(@"%@",msg);
}


@end