[iOS基础控件 - 6.4] 汽车品牌展示 Model嵌套/KVC/TableView索引

A.需求

1.使用汽车品牌名称头字母为一个Model，汽车品牌为一个Model，头字母Model嵌套品牌Model

2.使用KVC进行Model封装赋值

3.展示头字母标题

4.展示索引（使用KVC代替遍历取出所有索引值）

B.实现

1.Model嵌套

其实就是将另一个Model作为成员

.plist 文件结构

GroupCar中有存储Car的数组

 @property(nonatomic, strong) NSArray *cars;

封装Model的时候需要进行相应处理

CarGroup.m

         // 这里不能用KVC，封装car model再放到array中，不能直接存储array
         NSArray *carsArray = dictionary[@"cars"];
         NSMutableArray *mcarsArray = [NSMutableArray array];
         for (NSDictionary *dict in carsArray) {
             Car *car = [Car carWithDictionary:dict];
             [mcarsArray addObject:car];
         }

         self.cars = mcarsArray;

2.KVC

成员名使用和从dictionary取出来的键名一致，从而能用一个方法赋值所有成员属性，所见代码量

 Car.m
 - (instancetype) initWithDictionary:(NSDictionary *) dictionary {
     if (self = [super init]) {
         // 当dictionary中的键名跟Model中的成员名一致的时候，可以使用KVC
         [self setValuesForKeysWithDictionary:dictionary];

 //        self.icon = dictionary[@"icon"];
 //        self.name = dictionary[@"name"];
     }

     return self;
 }
  

3.展示标题 setTitle

 /** 设置section头部标题 */
 - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section

4.索引

 /** 索引 */
 - (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView {
     // 使用KVC取出数组，不用使用遍历封装
     return [self.carGroups valueForKey:@"title"];
 }

C.主要代码

 //
 //  Car.h
 //  CarGroup
 //
 //  Created by hellovoidworld on 14/12/2.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import <Foundation/Foundation.h>

 @interface Car : NSObject

 @property(nonatomic, copy) NSString *icon;
 @property(nonatomic, copy) NSString *name;

 - (instancetype) initWithDictionary:(NSDictionary *) dictionary;
 + (instancetype) carWithDictionary:(NSDictionary *) dictionary;
 + (instancetype) car;

 @end

 //
 //  Car.m
 //  CarGroup
 //
 //  Created by hellovoidworld on 14/12/2.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import "Car.h"

 @implementation Car

 - (instancetype) initWithDictionary:(NSDictionary *) dictionary {
     if (self = [super init]) {
         // 当dictionary中的键名跟Model中的成员名一致的时候，可以使用KVC
         [self setValuesForKeysWithDictionary:dictionary];

 //        self.icon = dictionary[@"icon"];
 //        self.name = dictionary[@"name"];
     }

     return self;
 }

 + (instancetype) carWithDictionary:(NSDictionary *) dictionary {
     return [[self alloc] initWithDictionary:dictionary];
 }

 + (instancetype) car {
     return [self carWithDictionary:nil];
 }

 @end

 //
 //  CarGroup.h
 //  CarGroup
 //
 //  Created by hellovoidworld on 14/12/2.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import <Foundation/Foundation.h>

 @interface CarGroup : NSObject

 @property(nonatomic, strong) NSArray *cars;
 @property(nonatomic, copy) NSString *title;

 - (instancetype) initWithDictionary:(NSDictionary *) dictionary;
 + (instancetype) carGroupWithDictionary:(NSDictionary *) dictionary;
 + (instancetype) carGroup;

 @end

 //
 //  CarGroup.m
 //  CarGroup
 //
 //  Created by hellovoidworld on 14/12/2.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import "CarGroup.h"
 #import "Car.h"

 @implementation CarGroup

 - (instancetype) initWithDictionary:(NSDictionary *) dictionary {
     if (self = [super init]) {
         self.title = dictionary[@"title"];

         // 这里不能用KVC，封装car model再放到array中，不能直接存储array
         NSArray *carsArray = dictionary[@"cars"];
         NSMutableArray *mcarsArray = [NSMutableArray array];
         for (NSDictionary *dict in carsArray) {
             Car *car = [Car carWithDictionary:dict];
             [mcarsArray addObject:car];
         }

         self.cars = mcarsArray;
     }

     return self;
 }

 + (instancetype) carGroupWithDictionary:(NSDictionary *) dictionary {
     return [[self alloc] initWithDictionary:dictionary];
 }

 + (instancetype) carGroup {
     return [self carGroupWithDictionary:nil];
 }

 @end

 //
 //  ViewController.m
 //  CarGroup
 //
 //  Created by hellovoidworld on 14/12/1.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import "ViewController.h"
 #import "CarGroup.h"
 #import "Car.h"

 @interface ViewController () <UITableViewDataSource>
 @property (weak, nonatomic) IBOutlet UITableView *tableView;

 // 所有的车品牌
 @property(nonatomic, strong) NSArray *carGroups;

 @end