ios14--购物车优化2

//
//  ViewController.m
//  03-综合练习
//
//  Created by xiaomage on 15/12/28.
//  Copyright © 2015年 小码哥. All rights reserved.
//

#import "ViewController.h"

@interface ViewController ()

// 购物车
@property (weak, nonatomic) IBOutlet UIView *shopCarView;
// 添加按钮
@property (weak, nonatomic) IBOutlet UIButton *addButton;
// 删除按钮
@property (weak, nonatomic) IBOutlet UIButton *removeButton;

/** 数据数组 */
@property (nonatomic, strong) NSArray *dataArr;
@end

@implementation ViewController
/**
 *  懒加载
    1.作用:
    1>用到的时候再加载
    2>全局只会被加载一次
    3>全局都可以使用
 
    过程:
    1.重写成员变量的get方法
    2.在get方法中判断:
      1>如果为空,加载数据
      2>如果不为空,就直接返回数据
 */
- (NSArray *)dataArr{
    if (_dataArr == nil) {
        // 加载数据
        self.dataArr = @[
                     @{@"name":@"单肩包", @"icon":@"danjianbao"},
                     @{@"name":@"钱包", @"icon":@"qianbao"},
                     @{@"name":@"链条包", @"icon":@"liantiaobao"},
                     @{@"name":@"手提包", @"icon":@"shoutibao"},
                     @{@"name":@"双肩包", @"icon":@"shuangjianbao"},
                     @{@"name":@"斜挎包", @"icon":@"xiekuabao"}
                     ];
    }
    return _dataArr;
}

// 初始化数据
- (void)viewDidLoad {
    [super viewDidLoad];
    
//    NSArray<NSDictionary *> *dataArr = @[
//                                         @{@"name":@"单肩包", @"icon":@"danjianbao"},
//                                         @{@"name":@"钱包", @"icon":@"qianbao"},
//                                         @{@"name":@"链条包", @"icon":@"liantiaobao"},
//                                         @{@"name":@"手提包", @"icon":@"shoutibao"},
//                                         @{@"name":@"双肩包", @"icon":@"shuangjianbao"},
//                                         @{@"name":@"斜挎包", @"icon":@"xiekuabao"}
//                                         ];
//    self.dataArr = dataArr;
}

/**
 *  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 = 3;
    // 2.商品的宽度 和 高度
    CGFloat width = 80;
    CGFloat height = 100;
    // 3.求出水平间距 和 垂直间距
    CGFloat hMargin = (self.shopCarView.frame.size.width - allCols * width) / (allCols -1);
    CGFloat vMargin = (self.shopCarView.frame.size.height - 2 * height) / 1;
    // 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*****************************/
  // 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];
    
/***********************3.设置数据*****************************/
    // 方式四 (数组 + 字典)
    /*
    NSArray<NSDictionary *> *dataArr = @[
                                         @{@"name":@"单肩包", @"icon":@"danjianbao"},
                                         @{@"name":@"钱包", @"icon":@"qianbao"},
                                         @{@"name":@"链条包", @"icon":@"liantiaobao"},
                                         @{@"name":@"手提包", @"icon":@"shoutibao"},
                                         @{@"name":@"双肩包", @"icon":@"shuangjianbao"},
                                         @{@"name":@"斜挎包", @"icon":@"xiekuabao"}
                                   ];
         */
    // 懒加载
    /*
    if (self.dataArr == nil) {
        self.dataArr = @[
                         @{@"name":@"单肩包", @"icon":@"danjianbao"},
                         @{@"name":@"钱包", @"icon":@"qianbao"},
                         @{@"name":@"链条包", @"icon":@"liantiaobao"},
                         @{@"name":@"手提包", @"icon":@"shoutibao"},
                         @{@"name":@"双肩包", @"icon":@"shuangjianbao"},
                         @{@"name":@"斜挎包", @"icon":@"xiekuabao"}
                         ];
    }
     */
    // 设置数据
    NSDictionary *dict = self.dataArr[index];//调用get方法
    iconView.image = [UIImage imageNamed:dict[@"icon"]];
    titleLabel.text = dict[@"name"];
/***********************4.设置按钮的状态*****************************/

    button.enabled = (index != 5);
    
    // 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
    /*
    if (self.shopCarView.subviews.count == 0) {
        self.removeButton.enabled = NO;
    }
     */
    self.removeButton.enabled = (self.shopCarView.subviews.count != 0);
    
}
@end