何为架构？
架构（Architecture）
软件开发中的设计方案
类与类之间的关系、模块与模块之间的关系、客户端与服务端的关系
经常听到的架构名词
MVC、MVP、MVVM、VIPER、CDD
三层架构、四层架构
......
传统的MVC模式
Traditional MVC
苹果的 MVC
苹果官网地址
[Cocoa MVC]
示例：
Model
@interface ShopModel : NSObject
@property (copy, nonatomic) NSString *title;
@property (copy, nonatomic) NSString *price;
@end
@implementation ShopModel
@end
DataSource
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *ID = @"CellID";
UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:ID];
if (!cell) {
cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:ID];
}
ShopModel *shop = self.shopData[indexPath.row];
***************************************
cell和model之间并没有直接关系
***************************************
cell.detailTextLabel.text = shop.price;
cell.textLabel.text = shop.title;
return cell;
}
优点：View、Model可以重复利用，可以独立使用
缺点：Controller的代码过于臃肿
MVC – 变种
示例：
Model
@interface TestModel : NSObject
@property (copy, nonatomic) NSString *title;
@property (copy, nonatomic) NSString *imageName;
@end
@implementation TestModel
@end
View
@class TestModel;
@interface TestView : UIView
@property (strong, nonatomic) TestModel * model;
@end
@implementation TestView
- (instancetype)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame]) {
.....
}
return self;
}
- (void)setModel:(TestModel *)model{
_model = model;
self.iconView.image = [UIImage imageNamed:model.imageName];
self.nameLabel.text = model.title;
}
@end
VC
- (void)viewDidLoad {
[super viewDidLoad];
TestModel *model = [[TestModel alloc] init];
model.title = @"QQ";
model.imageName = @"QQ";
TestView *testView = [[TestView alloc] init];
testView.model = model;
}
优点：对Controller进行瘦身，将View内部的细节封装起来了，外界不知道View内部的具体实现
缺点：View依赖于Model
MVP
Passive View variant of MVP
示例：
View
@interface TestView : UIView
- (void)setTitle:(NSString *)title andImageName:(NSString *)imageName;
@end
@implementation TestView
- (void)setTitle:(NSString *)title andImageName:(NSString *)imageName
{
_iconView.image = [UIImage imageNamed:image];
_nameLabel.text = title;
}
@end
VC
@interface ViewController ()
@property (strong, nonatomic) TestPresenter *presenter;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.presenter = [[TestPresenter alloc] initWithController:self];
}
@end
presenter
@interface TestPresenter : NSObject
- (instancetype)initWithController:(UIViewController *)controller;
@end
@implementation TestPresenter
- (instancetype)initWithController:(UIViewController *)controller
{
if (self = [super init]) {
self.controller = controller;
// 创建View
TestView *testView = [[TestView alloc] init];
testView.frame = CGRectMake(100, 100, 100, 150);
[controller.view addSubview:testView];
// 加载模型数据
TestModel *model = [[TestModel alloc] init];
model.title = @"QQ";
model.imageName = @"QQ";
// 赋值数据
[testView setName:model.title andImage:model.imageName];
}
return self;
}
@end
可以看到跟苹果的Apple’s MVC 很相似，多了一个 Presenter 模块，取代了Controller中转粘合剂的位置。Presenter本身与当前的ViewController中的生命周期并无关联,作为业务处理层,个人觉得称MVCP更合适
MVVM
MVVM
示例：
View
@class TestViewModel;
@interface TestView : UIView
@property (weak, nonatomic) TestViewModel *viewModel;
@end
@implementation TestView
- (instancetype)initWithFrame:(CGRect)frame
{
if (self = [super initWithFrame:frame]) {
....
}
return self;
}
- (void)setViewModel:(TestViewModel *)viewModel
{
_viewModel = viewModel;
__weak typeof(self) waekSelf = self;
[self.KVOController observe:viewModel keyPath:@"title" options:NSKeyValueObservingOptionNew block:^(id _Nullable observer, id _Nonnull object, NSDictionary * _Nonnull change) {
waekSelf.nameLabel.text = change[NSKeyValueChangeNewKey];
}];
[self.KVOController observe:viewModel keyPath:@"imageName" options:NSKeyValueObservingOptionNew block:^(id _Nullable observer, id _Nonnull object, NSDictionary * _Nonnull change) {
waekSelf.iconView.image = [UIImage imageNamed:change[NSKeyValueChangeNewKey]];
}];
}
VC
@interface ViewController ()
@property (strong, nonatomic) TestViewModel *viewModel;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.viewModel = [[TestViewModel alloc] initWithController:self];
}
@end
ViewModel
@interface TestViewModel : NSObject
- (instancetype)initWithController:(UIViewController *)controller;
@end
@interface TestViewModel()
@property (copy, nonatomic) NSString *title;
@property (copy, nonatomic) NSString *imageName;
@end
@implementation TestViewModel
- (instancetype)initWithController:(UIViewController *)controller
{
if (self = [super init]) {
// 创建View
TestView *testView = [[TestView alloc] init];
testView.frame = CGRectMake(100, 100, 100, 150);
testView.viewModel = self;
[controller.view addSubview:testView];
// 加载模型数据
TestModel *model = [[TestModel alloc] init];
model.title = @"QQ";
model.imageName = @"QQ";
// 设置数据
self.title = model.title;
self.imageName = model.imageName;
}
return self;
}
在MVP的基础上，将P改成与V双向绑定的VM就变成了MVVM,个人觉得称为MVCVM更合适 View <-> C <-> ViewModel <-> Model
KVO监听属性是用的Facebook的开源框架 KVOController https://github.com/facebookarchive/KVOController
三层架构、四层架构
示例
Data
@interface HTTPTool : NSObject
+ (void)GET:(NSString *)URL params:(NSDictionary *)params success:(void (^)(id result))success failure:(void (^)(NSError *error))failure;
@end
@implementation HTTPTool
+ (void)GET:(NSString *)URL params:(NSDictionary *)params success:(void (^)(id))success failure:(void (^)(NSError *))failure{
// 调用AFN
}
@end
@interface DBTool : NSObject
@end
@implementation DBTool
@end
Service
@interface Service : NSObject
+ (void)loadData:(NSDictionary *)params success:(void (^)(NSArray *newsData))success failure:(void (^)(NSError *error))failure;
@end
@implementation Service
+ (void)loadData:(NSDictionary *)params success:(void (^)(NSArray *newsData))success failure:(void (^)(NSError *error))failure;
{
// 先取出本地数据
// [DBTool loadLocalData....];
// 如果没有本地数据，就加载网络数据
// [HTTPTool GET:@"xxxx" params:nil success:^(id result) {
// success(array);
// } failure:failure];
}
@end
设计模式
设计模式（Design Pattern）
是一套被反复使用、代码设计经验的总结
使用设计模式的好处是：可重用代码、让代码更容易被他人理解、保证代码可靠性
一般与编程语言无关，是一套比较成熟的编程思想
设计模式可以分为三大类
创建型模式：对象实例化的模式，用于解耦对象的实例化过程
单例模式、工厂方法模式，等等结构型模式：把类或对象结合在一起形成一个更大的结构
代理模式、适配器模式、组合模式、装饰模式，等等行为型模式：类或对象之间如何交互，及划分责任和算法
观察者模式、命令模式、责任链模式，等等