uicollectionview 纯代码布局, 添加头部视图

#import <UIKit/UIKit.h>

@interface myHeadView : UICollectionReusableView
{
    UILabel   *TitleLable;
}
-(void)setTextTitle;
@end

#import "myHeadView.h"

@implementation myHeadView

-(instancetype)initWithFrame:(CGRect)frame{
    if (self =[super initWithFrame:frame]) {
        [self createUI];
    }
    return self;
}
-(void)createUI{
    
    TitleLable= [[UILabel alloc]initWithFrame:CGRectMake(10, 10, 100, 100)];
    [self addSubview:TitleLable];
}
//这是头部
-(void)setTextTitle
{
    TitleLable.text=@"哈哈";
    
}
@end

  

#import "ViewController.h"
#import "myHeadView.h"
#import "myHeadView.h"
@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>
{
    UICollectionView  *_myConllectionView;
    NSMutableArray    *_dataArray;
}
@end

@implementation ViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    _dataArray =[[NSMutableArray alloc]initWithObjects:[UIColor redColor],[UIColor greenColor],[UIColor blueColor],[UIColor grayColor],[UIColor lightGrayColor],[UIColor purpleColor], nil];
    
    UICollectionViewFlowLayout    *layout=[[UICollectionViewFlowLayout alloc]init];
    [layout setHeaderReferenceSize:CGSizeMake(320, 50)]; //设置headview 的大小
    layout.minimumInteritemSpacing=10; //cell之间左右的
    layout.minimumLineSpacing=10;      //cell上下间隔
    layout.itemSize=CGSizeMake(80,140);  //cell的大小
    layout.sectionInset=UIEdgeInsetsMake(5, 9, 5, 9);
    layout.headerReferenceSize = CGSizeMake(320, 50);
    
    _myConllectionView =[[UICollectionView alloc]initWithFrame:self.view.bounds collectionViewLayout:layout];
    [_myConllectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cell"];
    [_myConllectionView registerClass:[myHeadView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeadView"];
    
    _myConllectionView.delegate=self;
    _myConllectionView.dataSource=self;
    [self.view addSubview:_myConllectionView];
    
    
}

-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 2;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return _dataArray.count;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    
    UICollectionViewCell  *cell=[collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];
    cell.backgroundColor=[_dataArray objectAtIndex:indexPath.row];
    return cell;
}

-(UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
    UICollectionReusableView *reusableview = nil;
    NSLog(@"kind = %@", kind);
    if (kind == UICollectionElementKindSectionHeader){
    
        myHeadView *headerV = (myHeadView *)[collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeadView" forIndexPath:indexPath];
        [headerV setTextTitle];
        reusableview = headerV;
    }
    
    return reusableview;
    
}

@end