iOS中"查看更多/收起"功能实现

实现效果如图:

查看更多功能在很多app种都有应用,在这里简单的实现,介绍实现流程:

一个tableViewCell中包含一个collectionView,"查看更多"按钮是tableView的footerView

在控制器中ViewController .m中

#import "ViewController.h"
#import "ZSTableViewCell.h"

@interface ViewController ()<UITableViewDelegate,UITableViewDataSource>

@property (nonatomic,strong) UITableView *tableView;

//存放标题的数组
@property (nonatomic,strong) NSArray *titleArray;

@property (nonatomic,strong) UIButton *changeButton;

@property (nonatomic,assign) BOOL isOpen;

@property (nonatomic,assign) NSInteger showButtonNumber;

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.tableView = [[UITableView alloc]initWithFrame:[UIScreen mainScreen].bounds style:UITableViewStylePlain];
    
    [self.view addSubview:self.tableView];
    
    self.tableView.delegate = self;
    self.tableView.dataSource = self;
   
    [self.tableView registerClass:[ZSTableViewCell class] forCellReuseIdentifier:@"TheCell"];
   
    self.title = @"查看更多/收起";
    self.isOpen = NO;
    [self.changeButton setTitle:@"查看更多" forState:UIControlStateNormal];
    self.changeButton.backgroundColor = [UIColor clearColor];
    
    UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc]init];
    flowLayout.itemSize = CGSizeMake(([UIScreen mainScreen].bounds.size.width - 3)/4, 29);
    _showButtonNumber = 8;
    _titleArray = @[@"东方不败",@"岳不群",@"林平之",@"令狐冲",@"岳灵珊",@"任我行",@"左冷禅",@"蓝凤凰",@"向问天",@"田伯光",@"风清扬",@"任盈盈",@"路人甲",@"路人乙",@"路人丙"];
}
#pragma  mark --懒加载
//查看更多/收起按钮
- (UIButton *)changeButton{
    if (_changeButton == nil) {
        _changeButton = [UIButton buttonWithType:UIButtonTypeCustom];
        _changeButton.frame = CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width, 30);
        [_changeButton addTarget:self action:@selector(buttonClick:) forControlEvents:UIControlEventTouchUpInside];
        [_changeButton setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];
        [_changeButton setBackgroundColor:[UIColor whiteColor]];
        _changeButton.layer.cornerRadius = 5;
        _changeButton.layer.masksToBounds = YES;
        _changeButton.layer.borderWidth = 1;
        _changeButton.layer.borderColor = [UIColor greenColor].CGColor;
        
    }
    return _changeButton;
}
//button点击事件
- (void)buttonClick:(UIButton *)sender{
    //如果不是展开状态
    if (self.isOpen == NO) {
        [self.changeButton setTitle:@"收起" forState:UIControlStateNormal];
        self.isOpen = YES;
        _showButtonNumber = _titleArray.count;
        
    }else{
        [self.changeButton setTitle:@"查看更多" forState:UIControlStateNormal];
        self.isOpen = NO;
        _showButtonNumber = 8;
    }
    //刷新 动画效果 第0个section  NSIndexSet索引集合
    [self.tableView reloadSections:[NSIndexSet indexSetWithIndex:0] withRowAnimation:(UITableViewRowAnimationAutomatic)];
    /*
     
     UITableViewRowAnimationFade,  消失
     UITableViewRowAnimationRight,  从右滑行     // slide in from right (or out to right)
     UITableViewRowAnimationLeft,
     UITableViewRowAnimationTop,
     UITableViewRowAnimationBottom,
     UITableViewRowAnimationNone,            // available in iOS 3.0
     UITableViewRowAnimationMiddle,
     UITableViewRowAnimationAutomatic 自动
     */

}

#pragma mark --
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView{
    return 1;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return 1;
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
    //根据标识返回不同的高度
    if (self.isOpen == YES) {
        //因为每行有4个item,要多出空余的item
        CGFloat height = (self.titleArray.count / 4 + 1) * 30;
        return height;
    }else{
        return 60;
    }
}

- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section{
    return 0.5;
}
- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section{
    return 30;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{
    ZSTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"TheCell" forIndexPath:indexPath];
    [cell setupCellWithNum:_showButtonNumber ButtonNameArr:_titleArray];
    
    cell.buttonClick = ^(NSInteger index){
        NSLog(@"点击的按钮标签为%ld",index);
    };
   
    return  cell;
}
//footview
- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section{
    UIView *firstFootView = [[UIView alloc]initWithFrame:self.changeButton.frame];
    [firstFootView addSubview:self.changeButton];
    firstFootView.backgroundColor = [UIColor orangeColor];
    return firstFootView;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}


@end

在tableViewCell的.h中

#import <UIKit/UIKit.h>

@interface ZSTableViewCell : UITableViewCell
//点击cell的回调
@property (nonatomic,copy) void (^buttonClick)(NSInteger index);

- (void)setupCellWithNum:(NSInteger)buttonCount ButtonNameArr:(NSArray *)buttonArray;

@end

tableViewCell的.m

#import "ZSTableViewCell.h"
#import "TheItemCell.h"

@interface ZSTableViewCell ()<UICollectionViewDataSource,UICollectionViewDelegate>

@property (nonatomic,strong) UICollectionView *collectionView;

@property (nonatomic,assign) NSInteger cellNum;//接受控制器传来的数组个数

@property (nonatomic,strong) NSArray *buttonTitleArray;

@end
@implementation ZSTableViewCell


- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{
    
    self = [super initWithStyle: style reuseIdentifier:reuseIdentifier];
    if (self) {
        
        //流水布局
        UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc]init];
        flowLayout.itemSize = CGSizeMake(([UIScreen mainScreen].bounds.size.width - 3)/4, 29);
        //行间距
        flowLayout.minimumLineSpacing = 1;
        //列间距
        flowLayout.minimumInteritemSpacing = 1;
        //设置item偏移量 上 左 下 右
        flowLayout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0);
        self.collectionView.scrollEnabled = NO;
        
        CGFloat height = (15 / 5 +1) * 30;
        self.collectionView = [[UICollectionView alloc]initWithFrame:CGRectMake(0, 0, [UIScreen mainScreen].bounds.size.width,height) collectionViewLayout:flowLayout];
        [self.contentView addSubview:self.collectionView];
        //注册,必须先创建完collectionView,并且添加到父控件,才能注册,不然会报错
        [self.collectionView registerClass:[TheItemCell class] forCellWithReuseIdentifier:@"Cell"];
        self.collectionView.backgroundColor = [UIColor whiteColor];
        self.backgroundColor = [UIColor orangeColor];
    }
    
    self.collectionView.delegate = self;
    self.collectionView.dataSource = self;
    return self;
}

- (void)setupCellWithNum:(NSInteger)buttonCount ButtonNameArr:(NSArray *)buttonArray{
    self.cellNum = buttonCount;
    self.buttonTitleArray = buttonArray;
    [self.collectionView reloadData];
}
#pragma mark --
//返回item
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
    NSLog(@"%ld",(long)_cellNum);
    return _cellNum;
}
//返回组
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{
    return 1;
}


- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
    TheItemCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"Cell" forIndexPath:indexPath];
    cell.label.text = self.buttonTitleArray[indexPath.item];
    cell.backgroundColor = [UIColor blueColor];
    return cell;
}
//点击cell
- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath{
    self.buttonClick(indexPath.row);
}


- (void)setSelected:(BOOL)selected animated:(BOOL)animated {
    [super setSelected:selected animated:animated];

    // Configure the view for the selected state
}

@end

在collectionViewCell.h

#import <UIKit/UIKit.h>

@interface TheItemCell : UICollectionViewCell

@property (nonatomic,strong) UILabel *label;

@end

collectionViewCell的.m中

#import "TheItemCell.h"

@implementation TheItemCell

- (instancetype)initWithFrame:(CGRect)frame{
    self = [super initWithFrame:frame];
    if (self) {
        self.label = [[UILabel alloc]initWithFrame:self.bounds];
        self.label.textAlignment = NSTextAlignmentCenter;
        [self.contentView addSubview:self.label];
    }
    return self;
}


@end