李洪强iOS开发之UICollectionView的使用

想做如下的界面效果(纯代码)

------------------------------------------------------------------------------------

----------------------------------------------------------------------------

//

//  ViewController.m

//  A22 - 李洪强CollectionVIew的使用

//

//  Created by vic fan on 16/7/4.

//  Copyright © 2016年 李洪强. All rights reserved.

//

#define SCREENW [UIScreen mainScreen].bounds.size.width

#define SCREENH [UIScreen mainScreen].bounds.size.height

#import "ViewController.h"

#import "LHQHeadCellView.h"

#import "LHQPromptBuyCell.h"

@interface ViewController ()<UICollectionViewDelegate,UICollectionViewDataSource,UICollectionViewDelegateFlowLayout>{

}

/**

*  父页面

*/

@property(nonatomic,strong)UICollectionView *collectionView;

@end

static NSString *const bannerId = @"bannerId";//轮播cell

static NSString *const PromptBuyId = @"PromptBuyId";//直接购买

static NSString *const fastBuyId = @"fastBuyId";//快速购买

static NSString *const dataId = @"dataID";//

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

[self setUpUI];

}

/**

*  创建UI

*/

- (void)setUpUI{

/**

*  1 创建布局对象

*/

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

//  2 设置横向滚动

flowlayout.scrollDirection = UICollectionViewScrollDirectionVertical;

/**

*  3 初始化collectionVIew 并且设置flowlayout

*/

_collectionView = [[UICollectionView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, [UIScreen mainScreen].bounds.size.height) collectionViewLayout:flowlayout];

/**

*  4 设置_collectionView的背景颜色

*/

_collectionView.backgroundColor = [UIColor grayColor];

/**

*  5 设置collectionVIew的代理和数据源的方法

*/

_collectionView.delegate = self;

_collectionView.dataSource = self;

/**

*  6 添加到主页面

*/

[self.view addSubview:_collectionView];

/**

*  7 collectionViewcell的注册

*/

[_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:bannerId];

[_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:PromptBuyId];

[_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:fastBuyId];

[_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:dataId];

//头视图和尾部视图的注册

[_collectionView registerClass:[LHQHeadCellView class]  forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeadView"];

[_collectionView registerClass:[UICollectionReusableView class]  forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"FooterView"];

}

//----------------------------------------------------

#pragma mark  collectionView代理方法

/**

*  代理方法1 返回几组cell

*

*/

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

return 4;

}

/**

*  代理方法2 每组有几个cell

*

*/

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

switch (section) {

case 0:{

return 1;

}

break;

case 1:{

return 2;

}

break;

case 2:{

return 4;

}

break;

case 3:{

return 3;

}

break;

default:{

return 0;

}

break;

}

}

/**

*  代理方法3 每个item的大小

*/

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{

switch (indexPath.section) {

case 0:{

return CGSizeMake(SCREENW - 10, 150);

}

break;

case 1:{

return CGSizeMake(SCREENW/2 - 40, 150);

}

break;

case 2:{

return CGSizeMake(SCREENW / 2 - 10, 100);

}

break;

case 3:{

return CGSizeMake(SCREENW / 3 - 10, 100);

}

break;

default:{

return CGSizeMake(0, 0);

}

break;

}

}

/**

*  代理方法4 cell显示的内容

*

*/

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

if (indexPath.section == 1) {

LHQPromptBuyCell *cell = (LHQPromptBuyCell *)[collectionView dequeueReusableCellWithReuseIdentifier:PromptBuyId forIndexPath:indexPath];

cell.backgroundColor = [UIColor whiteColor];

return cell;

}

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

cell.backgroundColor = [UIColor whiteColor];

return cell;

}

/**

*  代理方法5 补充元素的视图

快速购买

*/

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

/**

*  5.1先初始化reusableView

*/

UICollectionReusableView *reusableView = nil;

/**

*  5.2 判断如果是头部视图

*/

if(kind == UICollectionElementKindSectionHeader){

/**

*  拿到第二组和第三组

*/

if(indexPath.section == 2|| indexPath.section == 3){

LHQHeadCellView *headCellV = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"HeadView" forIndexPath:indexPath ];

reusableView = headCellV;

}

/**

*  5.3 是尾部视图

*

*/

}else if (kind == UICollectionElementKindSectionFooter){

reusableView = [collectionView dequeueReusableSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"FooterView" forIndexPath:indexPath];

}

return reusableView;

}

/**

*  代理方法6   每个item的间距

*/

-(CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section{

return 10;

}

/**

*  代理方法7 设置headView的大小

*/

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section{

if(section == 2 || section == 3){

return CGSizeMake(SCREENW , 25);

}

return CGSizeMake(SCREENW, 0);

}

/**

*  代理方法8 设置foot的大小

*/

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section{

return CGSizeMake(self.view.frame.size.width, 10);

}

/**

* 代理方法9 定义每个UICollectionView 的 margin

*/

- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{

if (section == 1) {

return UIEdgeInsetsMake(0, 20, 0, 20);

}else{

return UIEdgeInsetsMake(0, 5, 0, 5);

}

}

- (void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

@end