iOS 分组的CollectionView

根据字数分别设置两组数据cell的宽度

写一个#import “HeaderView.h”类继承于UICollectionReusableView

#import <UIKit/UIKit.h>@interface HeaderView : UICollectionReusableView/** titleLabel */@property (nonatomic,strong) UILabel *titleLabel;@end#import "HeaderView.h"@implementation HeaderView-(UILabel *)titleLabel{    if (_titleLabel == nil) {        _titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 10, 50, 20)];        _titleLabel.textColor = [UIColor greenColor];        _titleLabel.textAlignment = NSTextAlignmentCenter;    }    return _titleLabel;}- (void)awakeFromNib {    [super awakeFromNib];    // Initialization code}- (void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes{    [self addSubview:self.titleLabel];}

同理再写一个写一个#import “FooterView.h”类继承于UICollectionReusableView

#import <UIKit/UIKit.h>@interface FooterView : UICollectionReusableView/** titleLabel */@property (nonatomic,strong) UILabel *titleLabel;@end#import "FooterView.h"@implementation FooterView-(UILabel *)titleLabel{    if (_titleLabel == nil) {        _titleLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 10, 50, 20)];        _titleLabel.textColor = [UIColor greenColor];        _titleLabel.textAlignment = NSTextAlignmentCenter;    }    return _titleLabel;}- (void)awakeFromNib {    [super awakeFromNib];    // Initialization code}- (void)applyLayoutAttributes:(UICollectionViewLayoutAttributes *)layoutAttributes{    [self addSubview:self.titleLabel];}

在ViewController里面写上相应代码

#import "ViewController.h"#import "HeaderView.h"#import "FooterView.h"#import "CollectionViewCell.h"#define SCREEN_WIDTH ([[UIScreen mainScreen] respondsToSelector:@selector(nativeBounds)]?[UIScreen mainScreen].nativeBounds.size.width/[UIScreen mainScreen].nativeScale:[UIScreen mainScreen].bounds.size.width)#define SCREENH_HEIGHT ([[UIScreen mainScreen] respondsToSelector:@selector(nativeBounds)]?[UIScreen mainScreen].nativeBounds.size.height/[UIScreen mainScreen].nativeScale:[UIScreen mainScreen].bounds.size.height)#ifdef DEBUG // 开发阶段-DEBUG阶段:使用Log#define NSLog(FORMAT, ...) fprintf(stderr,"%s:%d\t%s\n",[[[NSString stringWithUTF8String:__FILE__] lastPathComponent] UTF8String], __LINE__, [[NSString stringWithFormat:FORMAT, ##__VA_ARGS__] UTF8String]);#else // 发布阶段-上线阶段:移除Log#define NSLog(FORMAT, ...) nil#endif@interface ViewController ()<UICollectionViewDataSource,UICollectionViewDelegate,UICollectionViewDelegateFlowLayout>/** shuzu */@property (nonatomic,strong) NSArray *stringArray1;/** shuzu */@property (nonatomic,strong) NSArray *stringArray2;@property (nonatomic,strong) UICollectionView *collectionView;@property (nonatomic,strong) UICollectionViewFlowLayout *collectionViewFlowLayout;@end@implementation ViewController-(UICollectionView *)collectionView{    if (_collectionView==nil) {        _collectionViewFlowLayout = [[UICollectionViewFlowLayout alloc]init];        _collectionView = [[UICollectionView alloc]initWithFrame:CGRectMake(0, 20, SCREEN_WIDTH, SCREENH_HEIGHT-20) collectionViewLayout:self.collectionViewFlowLayout];        _collectionView.delegate = self;// 设置代理        _collectionView.dataSource = self; // 设置数据源代理        _collectionView.showsHorizontalScrollIndicator = NO;        _collectionView.backgroundColor = [UIColor colorWithRed:239/255.0f green:237/255.0f blue:237/255.0f alpha:1] ; // 设置背景        // 注册cell的类型        // 以代码的方式注册Cell的类型, 表示创建Cell的时候用这个类型来创建        /*         第一个参数: Cell的类型         第二个参数: 重用标志         *///        [_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"channelID"];        [_collectionView registerNib:[UINib nibWithNibName:@"CollectionViewCell" bundle:[NSBundle mainBundle]] forCellWithReuseIdentifier:@"channelID"];        // 3. 横向间距        _collectionViewFlowLayout.minimumInteritemSpacing = 5;        // 4. 纵向间距        _collectionViewFlowLayout.minimumLineSpacing = 10;        //新建headerView类, 继承自UICollectionReusableView        //注册header        /*         第一个参数:header视图对象的类型         第二个参数:区分是header还是后面的footer         // UICollectionElementKindSectionHeader表示header类型         第三个参数:重用标志         */        [_collectionView registerClass:[HeaderView class] forSupplementaryViewOfKind:UICollectionElementKindSectionHeader withReuseIdentifier:@"header"];////        //新建FooterView类, 继承自UICollectionReusableView//        //注册footer        [_collectionView registerClass:[FooterView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"footer"];    }    return _collectionView;}- (NSArray *)stringArray1{    if (_stringArray1 == nil) {        _stringArray1 = @[@"第一个参数",@"第一数新类一个参数",@"参数",@"第一个参数View类一个参数",@"第一个参数",@"建Fw类",@"第",@"第",@"第一个参数",@"第w类",@"第一个参数",@"第一个参数新ew类"];    }    return _stringArray1;}- (NSArray *)stringArray2{    if (_stringArray2 == nil) {        _stringArray2 = @[@"header视图",@"继承iew",@"heade类型",@"继承自UIC",@"head的类型",@"继承自ableView",@"heade",@"继承",@"header视",@"继承自UICw",@"head",@"继承自"];    }    return _stringArray2;}- (void)viewDidLoad {    [super viewDidLoad];    [self.view addSubview:self.collectionView];}-(NSArray*)layoutAttributesForElementsInRect:(CGRect)rect{    NSMutableArray* attributes = [[self.collectionViewFlowLayout layoutAttributesForElementsInRect:rect] mutableCopy];    for (UICollectionViewLayoutAttributes *attr in attributes) {        NSLog(@"%@", NSStringFromCGRect([attr frame]));    }    //从第二个循环到最后一个    for(int i = 1; i < [attributes count]; ++i) {        //当前attributes        UICollectionViewLayoutAttributes *currentLayoutAttributes = attributes[i];        //上一个attributes        UICollectionViewLayoutAttributes *prevLayoutAttributes = attributes[i - 1];        //我们想设置的最大间距，可根据需要改        NSInteger maximumSpacing = 0;        //前一个cell的最右边        NSInteger origin = CGRectGetMaxX(prevLayoutAttributes.frame);        //如果当前一个cell的最右边加上我们想要的间距加上当前cell的宽度依然在contentSize中，我们改变当前cell的原点位置        //不加这个判断的后果是，UICollectionView只显示一行，原因是下面所有cell的x值都被加到第一行最后一个元素的后面了        if(origin + maximumSpacing + currentLayoutAttributes.frame.size.width < self.collectionViewFlowLayout.collectionViewContentSize.width) {            CGRect frame = currentLayoutAttributes.frame;            frame.origin.x = origin + maximumSpacing;            currentLayoutAttributes.frame = frame;        }    }    return attributes;}#pragma mark - 遵守协议, 实现协议方法/* // 返回每一个Cell的对象 // UICollectionView上面的每一个Cell是UICollectionViewCell类型(或子类型)的对象 // UICollectionViewCell也是一个视图 */- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{    // 从重用队列里面获取    /*     第一个参数: 重用id     第二个参数: cell的位置     */    // UITableView      -> NSIndexPath:section row    // UICollectionView -> NSIndexPath:section item    CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"channelID" forIndexPath:indexPath];    // 不需要再创建, 从dequeueReusableCellWithReuseIdentifier方法李米娜一定能够获取到    // 设置背景颜色    cell.backgroundColor = [UIColor lightGrayColor];    cell.titlelabel.text = [NSString stringWithFormat:@"%@",indexPath.section ==0?self.stringArray1[indexPath.row]:self.stringArray2[indexPath.row]];    cell.titlelabel.font = [UIFont fontWithName:@"HelveticaNeue" size:10.0f];    cell.titlelabel.textColor = [UIColor whiteColor];    cell.layer.masksToBounds = YES;    cell.layer.cornerRadius = 15;    return cell;}#pragma mark - 在布局对象的代理协议方法中设置header的大小- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForHeaderInSection:(NSInteger)section{    return CGSizeMake(SCREEN_WIDTH, 40);}#pragma mark - 在布局对象的代理协议方法中设置footer的大小- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section{    return CGSizeMake(SCREEN_WIDTH, 0);}#pragma mark - 返回header对象 UICollectionViewDataSource的协议方法(也可以用来返回footer对象)- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath{    if (kind == UICollectionElementKindSectionHeader) {        // header类型        // 从重用队列里面获取        HeaderView *header = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"header" forIndexPath:indexPath];        // 设置背景颜色        header.backgroundColor = [UIColor redColor];//        [header addSubview:header.titleLabel];        // 显示数据        header.titleLabel.text = [NSString stringWithFormat:@"第%c组", (int)(indexPath.section + 'A')];        return header;    } else if (kind == UICollectionElementKindSectionFooter) {        // footer//         从重用队列里面获取        FooterView *footer = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"footer" forIndexPath:indexPath];        footer.backgroundColor = [UIColor purpleColor];        // 显示数据        footer.titleLabel.text = [NSString stringWithFormat:@"第%c组结束", (int)(indexPath.section + 'A')];        return footer;    }    return nil;}//#pragma mark - UICollectionViewDelegate methods- (NSInteger) numberOfSectionsInCollectionView:(UICollectionView *)collectionView{    return 2;}- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{    return section==0?self.stringArray1.count:self.stringArray2.count;}- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{    // 3.设置整个collectionView的内边距    CGFloat paddingY = 5;    CGFloat paddingX = 20;    return UIEdgeInsetsMake(paddingY, paddingX, paddingY, paddingX);}//- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{    // 2.设置每个格子的尺寸//    layout.itemSize = CGSizeMake(250, 250);    CGFloat nameW = [self withString:indexPath.section==0?self.stringArray1[indexPath.row]:self.stringArray2[indexPath.row]];    return CGSizeMake((nameW<=80)?80:nameW, 30);}- (CGFloat)withString:(NSString *)string{    //设置string字体  HelveticaNeue  Courier    UIFont *font = [UIFont fontWithName:@"HelveticaNeue" size:15.0f];    //根据字体得到nsstring的尺寸    CGSize size = [string sizeWithAttributes:[NSDictionary dictionaryWithObjectsAndKeys:font,NSFontAttributeName, nil]];    //名字的高//    CGFloat nameH = size.height;    //名字的宽    CGFloat nameW = size.width;    return nameW>SCREEN_WIDTH?SCREEN_WIDTH-20:nameW;}- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{    NSLog(@"点击的是%ld组的第%ld个cell",indexPath.section,indexPath.row);}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

效果图

项目地址