UICollectionView二级树展开-白红宇

公司项目是社区类的,上周就下载了些社区类APP看了下,发现小区无忧首页的顶部蛮好玩,就试着做了一下,现在先把UICollectionView的二级树展开功能分享一下 .

1.效果图

2.创建子CollectionView

////  DeatilView.h//  Spread////  Created by City--Online on 15/10/30.//  Copyright © 2015年 City--Online. All rights reserved.//#import 
    
     typedef void(^DetailIndexPathBlock) (NSIndexPath *indexPath);@interface DetailView : UIView@property (nonatomic,copy) DetailIndexPathBlock detailIndexPathBlock;- (instancetype)initWithFrame:(CGRect)frame withTitleArray:(NSArray *)titleArray;@end

////  DeatilView.m//  Spread////  Created by City--Online on 15/10/30.//  Copyright © 2015年 City--Online. All rights reserved.//#import "DetailView.h"static const int columns=4;static const float rowHeight=30.0;//static const int rows=2;@interface DetailView ()
    
     @property (nonatomic,strong) UICollectionView *collectionView;@property (nonatomic,strong) NSArray *titleArray;@end@implementation DetailView- (instancetype)initWithFrame:(CGRect)frame withTitleArray:(NSArray *)titleArray{    _titleArray=titleArray;    return [self initWithFrame:frame];}- (instancetype)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    if (self) {            UICollectionViewFlowLayout  *collectionViewFlowLayout=[[UICollectionViewFlowLayout alloc]init];        collectionViewFlowLayout.minimumInteritemSpacing=0.0;        collectionViewFlowLayout.minimumLineSpacing=0.0;        collectionViewFlowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;        collectionViewFlowLayout.sectionInset = UIEdgeInsetsMake(0.0, 0.0, 0, 0.0);                       float columuWidth=self.bounds.size.width/columns;        collectionViewFlowLayout.itemSize=CGSizeMake(columuWidth, rowHeight);        collectionViewFlowLayout.estimatedItemSize=CGSizeMake(columuWidth, rowHeight);               collectionViewFlowLayout.scrollDirection=UICollectionViewScrollDirectionVertical;                collectionViewFlowLayout.headerReferenceSize=CGSizeMake(0, 0);        collectionViewFlowLayout.footerReferenceSize=CGSizeMake(0, 0);                _collectionView=[[UICollectionView alloc]initWithFrame:self.bounds collectionViewLayout:collectionViewFlowLayout];        _collectionView.backgroundColor=[UIColor whiteColor];        _collectionView.delegate=self;        _collectionView.dataSource=self;        _collectionView.allowsSelection=YES;//        _collectionView.allowsMultipleSelection=YES;        [_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cell"];        [self addSubview:_collectionView];    }    return self;}- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{    return 1;}- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{    return _titleArray.count;}- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{    UICollectionViewCell *cell =[collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];    cell.backgroundColor = [UIColor colorWithRed:arc4random()%256/ 255.0  green:arc4random()%256 / 255.0 blue:arc4random()% 256 / 255.0  alpha:1];    return cell;}- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{    if (self.detailIndexPathBlock != nil) {        self.detailIndexPathBlock(indexPath);    }}@end

3.主视图

////  MainView.h//  Spread////  Created by City--Online on 15/10/30.//  Copyright © 2015年 City--Online. All rights reserved.//#import 
    
     @interface MainView : UIView- (instancetype)initWithFrame:(CGRect)frame withTitleArray:(NSArray *)mainArray;@end

////  MainView.m//  Spread////  Created by City--Online on 15/10/30.//  Copyright © 2015年 City--Online. All rights reserved.//#import "MainView.h"#import "DetailView.h"static const int columns=4;@interface MainView ()
    
     @property (nonatomic,strong) UICollectionView *collectionView;@property (nonatomic,strong) NSArray *mainArray;@property (nonatomic,strong) NSMutableArray *detailArray;@property (nonatomic,strong) NSIndexPath *selectIndexPath;@property (nonatomic,strong) DetailView *detailView;@property (nonatomic,assign) bool    *IsSpread;@end@implementation MainView- (instancetype)initWithFrame:(CGRect)frame withTitleArray:(NSArray *)mainArray{    _mainArray=mainArray;    _selectIndexPath=nil;    return [self initWithFrame:frame];}- (instancetype)initWithFrame:(CGRect)frame{    self = [super initWithFrame:frame];    if (self) {        UICollectionViewFlowLayout  *collectionViewFlowLayout=[[UICollectionViewFlowLayout alloc]init];        collectionViewFlowLayout.minimumInteritemSpacing=1.0;        collectionViewFlowLayout.minimumLineSpacing=0.0;        collectionViewFlowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;        collectionViewFlowLayout.sectionInset = UIEdgeInsetsMake(0.0, 0.0, 0, 0.0);        float columuWidth=(self.bounds.size.width-columns+1)/columns;        collectionViewFlowLayout.itemSize=CGSizeMake(columuWidth, columuWidth);        collectionViewFlowLayout.estimatedItemSize=CGSizeMake(columuWidth, columuWidth);        collectionViewFlowLayout.scrollDirection=UICollectionViewScrollDirectionVertical;        collectionViewFlowLayout.headerReferenceSize=CGSizeMake(0, 0);        collectionViewFlowLayout.footerReferenceSize=CGSizeMake(0, 0);        _collectionView=[[UICollectionView alloc] initWithFrame:self.bounds collectionViewLayout:collectionViewFlowLayout];        _collectionView.backgroundColor=[UIColor whiteColor];        _collectionView.delegate=self;        _collectionView.dataSource=self;        _collectionView.allowsSelection=YES;        [_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cell"];        [_collectionView registerClass:[UICollectionReusableView class] forSupplementaryViewOfKind:UICollectionElementKindSectionFooter withReuseIdentifier:@"footer"];        [self addSubview:_collectionView];    }    return self;}- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{    return columns;}- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{    UICollectionViewCell *cell =[collectionView dequeueReusableCellWithReuseIdentifier:@"cell" forIndexPath:indexPath];            cell.backgroundColor=indexPath.section%2? [UIColor redColor]:[UIColor yellowColor];    if (indexPath.section*columns+indexPath.row>_mainArray.count) {        cell.backgroundColor=[UIColor clearColor];    }    return cell;}- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{    if (_selectIndexPath!=indexPath&&_selectIndexPath!=nil) {        _IsSpread=YES;    }    else    {        _IsSpread=!_IsSpread;    }        if (!_IsSpread) {        //改变主CollectionView视图Frame和子CollectionView的Frame        self.frame=CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.width);    }    else    {        self.frame = CGRectMake(0, 0, self.bounds.size.width, self.bounds.size.width+((int)(_detailArray.count+3)/4)*30.0);    }        _collectionView.frame = self.frame;    _selectIndexPath=indexPath;    //改变数据源     _detailArray=[(@[@"AAA",@"BBB",@"CCC",@"DDD",@"EEE"]) mutableCopy];    [_collectionView reloadData];    }- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{    return (_mainArray.count+columns-1)/4;}//针对每个分区的页眉和页脚, 返回对应的视图对象, 重用的- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath{        UICollectionReusableView *footerView = [collectionView dequeueReusableSupplementaryViewOfKind:kind withReuseIdentifier:@"footer" forIndexPath:indexPath];        //将第二个视图控制器添加到区尾上    if (_detailView!=nil) {        [_detailView removeFromSuperview];        _detailView=nil;    }    _detailView =[[DetailView alloc] initWithFrame:CGRectMake(0, 0, self.bounds.size.width, ((int)(5+3)/4)*30.0) withTitleArray:_detailArray];    _detailView.detailIndexPathBlock=^(NSIndexPath *indexPath)    {        NSLog(@"%@",indexPath);    };    [footerView addSubview:_detailView];        return footerView;}- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section{    if (section==_selectIndexPath.section&&_IsSpread) {        return CGSizeMake(self.bounds.size.width, ((int)(_detailArray.count+3)/4)*30.0) ;    }    else    {        return CGSizeZero;    }}@end

4.调用

////  ViewController.m//  Spread////  Created by City--Online on 15/10/30.//  Copyright © 2015年 City--Online. All rights reserved.//#import "ViewController.h"#import "MainView.h"#import "DetailView.h"@interface ViewController ()@end@implementation ViewController- (void)viewDidLoad {    [super viewDidLoad];    MainView *mainView=[[MainView alloc]initWithFrame:CGRectMake(0, 0, self.view.bounds.size.width, self.view.bounds.size.width) withTitleArray:@[@"1",@"2",@"3",@"4",@"5",@"6"]];    [self.view addSubview:mainView];}- (void)didReceiveMemoryWarning {    [super didReceiveMemoryWarning];    // Dispose of any resources that can be recreated.}@end

5.结果图

今天又添加了ScrollView分页 demo地址:https://github.com/ywcui/Spread