iOS 购物车

看了小码哥的视频—》整理一个简单的购物车小demo。主要利用“通知”来实现事件的传递。通知的发布和监听、移除通知。
如上图所示：点击加减按钮可以改变购物数量，底部工具条上的总价也随之变化计算出相应的价格总和。减号按钮、清空购物车按钮 默认不能点击，当数量大于0时可以点击。
MVC模式！UITableView搭建基本骨架，自定义UITableVewCell，加减按钮的圆角边框处理。通知的发布监听、移除。
Model.h文件

#import <Foundation/Foundation.h>@interface MRootModle : NSObject@property (copy, nonatomic) NSString *money;@property (copy, nonatomic) NSString *name;@property (copy, nonatomic) NSString *image;//记录购物的数量（点击一下加号数量就增加一下，点击减号数量就减少一个）@property (nonatomic,assign)int count;

RootViewController.m文件

#import "RootViewController.h"#import "RootTableViewCell.h"#import "MRootModle.h"#import "MJExtension.h"#define ScreenWidth  [UIScreen mainScreen].bounds.size.width#define ScreenHeight  [UIScreen mainScreen].bounds.size.height@interface RootViewController ()<UITableViewDelegate,UITableViewDataSource>@property (nonatomic,strong)UITableView *tableView;@property (nonatomic,strong)NSArray *dataArray;//数据源@property (nonatomic,strong)UILabel *priceLabel;//总价价格@property (nonatomic,strong)UILabel *zongjiaLabel;//总价@property (nonatomic,strong)UIButton *clearBtn;//清空购物车@property (nonatomic,strong)UIButton *buyBtn;//购物@end@implementation RootViewController//数据源- (NSArray *)dataArray{    if (!_dataArray) {        _dataArray = [MRootModle  mj_objectArrayWithFilename:@"wine.plist"];    }       return _dataArray;}- (UITableView *)tableView{    if (!_tableView) {        _tableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 0,ScreenWidth, ScreenHeight-49) style:UITableViewStylePlain];        _tableView.delegate = self;        _tableView.dataSource = self;        _tableView.tableFooterView = [[UIView alloc]init];    }    return _tableView;}- (void)viewDidLoad {    [super viewDidLoad];    self.navigationItem.title = @"购物车";    [self.view addSubview:self.tableView];    [self creatFootView];    //监听通知    NSNotificationCenter *center = [NSNotificationCenter defaultCenter];    [center addObserver:self selector:@selector(plusClick:) name:@"plusClickNSNotification" object:nil];    [center addObserver:self selector:@selector(minusClick:) name:@"minusClickNSNotification" object:nil];}- (void)creatFootView{    //底部View    UIView *footView = [[UIView alloc]initWithFrame:CGRectMake(0, ScreenHeight-49, ScreenWidth, 49)];    footView.backgroundColor = [UIColor whiteColor];    [self.view addSubview:footView];    //黑线    UIView *line = [[UIView alloc]initWithFrame:CGRectMake(0, ScreenHeight-49, ScreenWidth, 1)];    line.backgroundColor = [UIColor blackColor];    line.alpha = 0.3;    [self.view addSubview:line];    //总价    _zongjiaLabel = [[UILabel alloc]initWithFrame:CGRectMake(15, 8, 60, 33)];    _zongjiaLabel.font = [UIFont systemFontOfSize:15];    _zongjiaLabel.text =@"总价:￥";    [footView addSubview:_zongjiaLabel];    //    _priceLabel = [[UILabel alloc]initWithFrame:CGRectMake(65, 8, 100, 33)];    _priceLabel.text = @"0";    _priceLabel.textColor = [UIColor redColor];    [footView addSubview:_priceLabel];    //购物    _buyBtn = [UIButton buttonWithType:UIButtonTypeCustom];    _buyBtn.frame = CGRectMake(ScreenWidth - 160, 8, 40, 33);    [_buyBtn setTitle:@"购物" forState:UIControlStateNormal];    [_buyBtn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];    _buyBtn.font = [UIFont systemFontOfSize:17];        [_buyBtn addTarget:self action:@selector(buyClick:) forControlEvents:UIControlEventTouchUpInside];    [footView addSubview:_buyBtn];    //清空购物车    _clearBtn = [UIButton buttonWithType:UIButtonTypeCustom];    _clearBtn.frame = CGRectMake(ScreenWidth-160, 8, 200, 33);    [_clearBtn setTitle:@"清空购物车" forState:UIControlStateNormal];    [_clearBtn setTitleColor:[UIColor blackColor] forState:UIControlStateNormal];    _clearBtn.font = [UIFont systemFontOfSize:17];    [_clearBtn addTarget:self action:@selector(clearClick:) forControlEvents:UIControlEventTouchUpInside];    [footView addSubview:_clearBtn];}//购买- (void)buyClick:(UIButton *)btn{    NSLog(@"购买");}//清空购物车- (void)clearClick:(UIButton *)btn{    //清除模型里的数据    for (MRootModle *model in _dataArray) {        model.count = 0;    }    //刷新表格数据    [self.tableView reloadData];    self.priceLabel.text = @"0";    self.clearBtn.enabled = NO;    NSLog(@"清空购物车");}//减号的通知事件- (void)plusClick:(NSNotification *)notif{    RootTableViewCell *cell =notif.object;    int price =self.priceLabel.text.intValue+cell.model.money.intValue;    //如果有文字就不行转换     _priceLabel.text = [NSString stringWithFormat:@"%d",price];    if (price>0) {        _clearBtn.enabled = YES;        [_buyBtn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];    }}//加号的通知事件- (void)minusClick:(NSNotification *)notif{    RootTableViewCell *cell = notif.object;    int price = self.priceLabel.text.intValue - cell.model.money.intValue;    _priceLabel.text =[NSString stringWithFormat:@"%d",price];    if (price==0) {        _clearBtn.enabled = NO;        [_buyBtn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal];    }}- (void)dealloc{    //移除通知    [[NSNotificationCenter defaultCenter]removeObserver:self];}/** 代理 */- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{    return self.dataArray.count;}- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath{    RootTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"iden"];    if (cell == nil) {        cell= [[RootTableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"iden"];    }    cell.model =_dataArray[indexPath.row];    cell.selectionStyle = UITableViewCellSelectionStyleNone;    return cell;}- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath{    [tableView deselectRowAtIndexPath:indexPath animated:YES];}

TableViewCell.m文件

@interface RootTableViewCell ()@property (nonatomic,strong)UIButton *jiaBtn;@property (nonatomic,strong)UIButton *jianBtn;@property (nonatomic,strong)UILabel *numLabel;@property (nonatomic,strong)UIImageView *headerImageView;@property (nonatomic,strong)UILabel *titletLabel;@property (nonatomic,strong)UILabel *danjiaLabel;@end@implementation RootTableViewCell- (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier{    if ([super initWithStyle:style reuseIdentifier:reuseIdentifier]) {        [self createUI];    }    return self;}- (void)createUI{    //图片    _headerImageView = [[UIImageView alloc]initWithFrame:CGRectMake(10, 2, 40, 40)];    _headerImageView.backgroundColor = [UIColor brownColor];    [self.contentView addSubview:_headerImageView];    //题目    _titletLabel = [[UILabel alloc]initWithFrame:CGRectMake(53, 0, 200, 30)];    _titletLabel.textColor = [UIColor orangeColor];    _titletLabel.font = [UIFont systemFontOfSize:11];    [self.contentView addSubview:_titletLabel];    //单价    _danjiaLabel = [[UILabel alloc]initWithFrame:CGRectMake(53, 25, 50, 20)];    _danjiaLabel.textColor = [UIColor orangeColor];    _danjiaLabel.font = [UIFont systemFontOfSize:11];    [self.contentView addSubview:_danjiaLabel];    //加号button    _jiaBtn = [UIButton buttonWithType:UIButtonTypeCustom];    _jiaBtn.frame = CGRectMake(ScreenWidth-50, 5, 35, 35);     [_jiaBtn setTitleColor:[UIColor blueColor] forState:UIControlStateNormal];    [_jiaBtn setTitle:@"+" forState:UIControlStateNormal];    [_jiaBtn addTarget:self action:@selector(jiaClick) forControlEvents:UIControlEventTouchUpInside];    [self custombutton:_jiaBtn];    //数量    _numLabel =[[UILabel alloc]initWithFrame:CGRectMake(ScreenWidth - 80, 12, 20, 20)];    _numLabel.font = [UIFont systemFontOfSize:11];    [self.contentView addSubview:_numLabel];    //减号button    _jianBtn = [UIButton buttonWithType:UIButtonTypeSystem];    [_jianBtn setTitle:@"-" forState:UIControlStateNormal];    _jianBtn.frame =CGRectMake(ScreenWidth-140, 5, 35, 35);    _jianBtn.enabled = NO;    [_jianBtn addTarget:self action:@selector(jianClick) forControlEvents:UIControlEventTouchUpInside];    [self custombutton:_jianBtn];}-(void)setModel:(MRootModle *)model{    _model =model;    NSLog(@"%@",model.image);    _headerImageView.image =[UIImage imageNamed:model.image];    _titletLabel.text = model.name;    _danjiaLabel.text = [NSString stringWithFormat:@"￥%@",model.money];    _numLabel.text =[NSString stringWithFormat:@"%d",model.count];    //判断减号能不能用    _jianBtn.enabled = (_model.count>0);}// + 按钮- (void)jiaClick{    NSLog(@"加一件");    self.model.count++;    _numLabel.text =[NSString stringWithFormat:@"%d",self.model.count];    if (_model.count>0) {        self.jianBtn.enabled = YES;    }    //发布通知    [[NSNotificationCenter defaultCenter]postNotificationName:@"plusClickNSNotification" object:self];}//  — 按钮- (void)jianClick{    self.model.count--;    _numLabel.text =[NSString stringWithFormat:@"%d",self.model.count];    if (!(self.model.count>0)) {        _numLabel.text =[NSString stringWithFormat:@"0"];        _jianBtn.enabled =NO;    }    //发布通知     [[NSNotificationCenter defaultCenter]postNotificationName:@"minusClickNSNotification" object:self];    NSLog(@"减一件");}//处理加减按钮的圆角边框- (void)custombutton:(UIButton *)btn{    btn.layer.cornerRadius = btn.frame.size.width*0.5;    btn.layer.borderWidth = 1;    btn.layer.borderColor = [UIColor orangeColor].CGColor;    [btn setTitleColor:[UIColor grayColor] forState:UIControlStateHighlighted];    btn.titleLabel.font = [UIFont systemFontOfSize:25];    [self.contentView addSubview:btn];}

当然也可以用KVO来关联view与model。取代通知下面贴出代码：

- (NSArray *)wineArray{    if (!_wineArray) {        _wineArray = [XMGWine mj_objectArrayWithFilename:@"wine.plist"];        NSLog(@"数据源%@",_wineArray);        for (XMGWine *wine in _wineArray) {            [wine addObserver:self forKeyPath:@"count" options:NSKeyValueObservingOptionNew| NSKeyValueObservingOptionOld context:nil];        }    }    return _wineArray;}- (void)viewDidLoad {    [super viewDidLoad];}- (void)dealloc {    for (XMGWine *wine in _wineArray) {        [wine removeObserver:self forKeyPath:@"count"];    }}#pragma mark - KVO- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(XMGWine *)wine change:(NSDictionary<NSString *,id> *)change context:(void *)context{    // NSKeyValueChangeNewKey == @"new"    int new = [change[NSKeyValueChangeNewKey] intValue];    // NSKeyValueChangeOldKey == @"old"    int old = [change[NSKeyValueChangeOldKey] intValue];    if (new > old) { // 数量增加,点击加号        // 计算总价        int totalPrice = self.totalPriceLabel.text.intValue + wine.money.intValue;        // 设置总价        self.totalPriceLabel.text = [NSString stringWithFormat:@"%d",totalPrice];        // 购买按钮一定能点击        self.buyButton.enabled = YES;    } else { // 数量减少,点击减号        // 计算总价        int totalPrice = self.totalPriceLabel.text.intValue - wine.money.intValue;        // 设置总价        self.totalPriceLabel.text = [NSString stringWithFormat:@"%d",totalPrice];        // 控制购买按钮是否能点击        self.buyButton.enabled = (totalPrice > 0);    }}