控制器：

//
// XMGViewController.h

#import

@interface XMGViewController : UIViewController
@end

//
// XMGViewController.m

#import "XMGViewController.h"
#import "XMGShop.h"
#import "XMGShopView.h"

@interface XMGViewController ()

@property (weak, nonatomic) IBOutlet UIView *shopCarView;
@property (weak, nonatomic) IBOutlet UIButton *addButton;
@property (weak, nonatomic) IBOutlet UIButton *removeButton;
@property (nonatomic, strong) NSArray *dataArr;

@end

@implementation XMGViewController
/**
* 懒加载
*/

• (NSArray *)dataArr{
  if (_dataArr == nil) {
  // 加载数据
  // 1.获取全路径
  NSString *dataPath = [[NSBundle mainBundle] pathForResource:@"shopData.plist" ofType:nil];
  self.dataArr = [NSArray arrayWithContentsOfFile:dataPath];
  // 字典转模型
  // 创建临时数组
  NSMutableArray *tempArray = [NSMutableArray array];
  for (NSDictionary *dict in _dataArr) {
  // 创建shop对象
  XMGShop *shop = [XMGShop shopWithDict:dict];
  // 把模型装入数组
  [tempArray addObject:shop];
  }
  self.dataArr = tempArray;
  }
  return _dataArr;
  }

// 初始化数据

• (void)viewDidLoad {
  [super viewDidLoad];
  }

/**
* 添加到购物车
*
* @param button 按钮
*/

• (IBAction)add:(UIButton *)button {
  /***********************1.定义一些常量*****************************/
  // 1.总列数
  NSInteger allCols = ;
  // 2.商品的宽度 和 高度
  CGFloat width = ;
  CGFloat height = ;
  // 3.求出水平间距 和 垂直间距
  CGFloat hMargin = (self.shopCarView.frame.size.width - allCols * width) / (allCols -);
  CGFloat vMargin = (self.shopCarView.frame.size.height - * height) / ;
  // 4. 设置索引
  NSInteger index = self.shopCarView.subviews.count;
  // 5.求出x值
  CGFloat x = (hMargin + width) * (index % allCols);
  CGFloat y = (vMargin + height) * (index / allCols);

/***********************2.创建一个商品*****************************/
/*
原来的分开创建：
// 1.创建商品的view
UIView *shopView = [[UIView alloc] init];

// 2.设置frame
shopView.frame = CGRectMake(x, y, width, height);

// 3.设置背景颜色
shopView.backgroundColor = [UIColor greenColor];

// 4.添加到购物车
[self.shopCarView addSubview:shopView];

// 5.创建商品的UIImageView对象
UIImageView *iconView = [[UIImageView alloc] init];
iconView.frame = CGRectMake(0, 0, width, width);
iconView.backgroundColor = [UIColor blueColor];
[shopView addSubview:iconView];

// 6.创建商品标题对象
UILabel *titleLabel = [[UILabel alloc] init];
titleLabel.frame = CGRectMake(0, width, width, height - width);
titleLabel.backgroundColor = [UIColor yellowColor];
titleLabel.textAlignment = NSTextAlignmentCenter; // 居中
[shopView addSubview:titleLabel];
*/

XMGShopView \*shopView = \[\[XMGShopView alloc\] init\];  
shopView.frame = CGRectMake(x, y, width, height);  
\[self.shopCarView addSubview:shopView\];

// shopView.titleLabel = nil;
/***********************3.设置数据*****************************/
// 设置数据
XMGShop *shop = self.dataArr[index];
/*
shopView.iconView.image = [UIImage imageNamed:shop.icon];
shopView.titleLabel.text = shop.name;
*/
[shopView setIcon:shop.icon];
[shopView setName:shop.name];

/***********************4.设置按钮的状态*****************************/

button.enabled = (index != );

// 5.设置删除按钮的状态  
self.removeButton.enabled = YES;

}

/**
* 从购物车中删除
*
* @param button 按钮
*/

• (IBAction)remove:(UIButton *)button {
  // 1. 删除最后一个商品
  UIView *lastShopView = [self.shopCarView.subviews lastObject];
  [lastShopView removeFromSuperview];

  // 3. 设置添加按钮的状态
  self.addButton.enabled = YES;

  // 4. 设置删除按钮的状态
  self.removeButton.enabled = (self.shopCarView.subviews.count != );

}
@end

自定义控件：

//
// XMGShopView.h

#import

@interface XMGShopView : UIView
// readonly 只会调用get方法
/** 图片控件 */
//@property (nonatomic, weak, readonly) UIImageView *iconView;// [self addSubview:iconView];已经有强指针引用了，这里用weak

/** 标题控件 */
//@property (nonatomic, weak, readonly) UILabel *titleLabel;

// 提供接口方法

• (void)setIcon: (NSString *)icon;
• (void)setName: (NSString *)name;
  @end

//
// XMGShopView.m

#import "XMGShopView.h"

@interface XMGShopView () //扩展属性
@property (nonatomic, strong) UIImageView *iconView;//[self addSubview:iconView];有强指针指向了，用weak
@property (nonatomic, strong) UILabel *titleLabel;
@end

@implementation XMGShopView

/**
* 初始化子控件(不要设置frame)
*
*/

• (instancetype)init{
  if (self = [super init]) {
  // 1.创建商品的UIImageView对象
  UIImageView *iconView = [[UIImageView alloc] init];
  iconView.backgroundColor = [UIColor blueColor];
  [self addSubview:iconView];
  _iconView = iconView;

  // 2.创建商品标题对象  
  UILabel \*titleLabel = \[\[UILabel alloc\] init\];  
  titleLabel.backgroundColor = \[UIColor yellowColor\];  
  titleLabel.textAlignment = NSTextAlignmentCenter; // 居中  
  \[self addSubview:titleLabel\];  
  \_titleLabel = titleLabel;  

  }
  return self;
  }

/**
* 布局子控件(可以拿到frame)
*/

• (void)layoutSubviews{
  // 0.一定要调用super
  [super layoutSubviews];

  // 1.获取当前控件的尺寸
  CGFloat width = self.frame.size.width;
  CGFloat height = self.frame.size.height;

  // 2.设置子控件的frame
  self.iconView.frame = CGRectMake(, , width, width);
  self.titleLabel.frame = CGRectMake(, width, width, height - width);
  }

• (void)setIcon:(NSString *)icon{
  // 设置数据
  self.iconView.image = [UIImage imageNamed:icon];
  }

• (void)setName:(NSString *)name{
  // 设置数据
  self.titleLabel.text = name;
  }

@end

bean:

//
// XMGShop.h

#import

@interface XMGShop : NSObject

/** 图片的名称 */
@property (nonatomic, copy) NSString *icon;
/** 商品的名称 */
@property (nonatomic, copy) NSString *name;

// 提供构造方法
/*

• (instancetype)initWithIcon: (NSString *)icon name: (NSString *)name;

• (instancetype)shopWithIcon: (NSString *)icon name: (NSString *)name;
  */

• (instancetype)initWithDict:(NSDictionary *)dict;

• (instancetype)shopWithDict:(NSDictionary *)dict;

@end

//
// XMGShop.m

#import "XMGShop.h"

@implementation XMGShop
/*

• (instancetype)initWithIcon:(NSString *)icon name:(NSString *)name{
  if (self = [super init]) {
  self.icon = icon;
  self.name = name;
  }
  return self;
  }

• (instancetype)shopWithIcon:(NSString *)icon name:(NSString *)name{
  return [[self alloc] initWithIcon:icon name:name];
  }
  */

• (instancetype)initWithDict:(NSDictionary *)dict{
  if (self = [super init]) {
  self.icon = dict[@"icon"];
  self.name = dict[@"name"];
  }
  return self;
  }

• (instancetype)shopWithDict:(NSDictionary *)dict{
  return [[self alloc] initWithDict:dict];
  }

@end