何為架構？
架構（Architecture）
軟件開發中的設計方案
類與類之間的關系、模塊與模塊之間的關系、客戶端與服務端的關系
經常聽到的架構名詞
MVC、MVP、MVVM、VIPER、CDD
三層架構、四層架構
......
傳統的MVC模式
Traditional MVC
蘋果的 MVC
[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之間并沒有直接關系
***************************************
cell.detailTextLabel.text = shop.price;
cell.textLabel.text = shop.title;
return cell;
}
優點：View、Model可以重復利用，可以獨立使用
缺點：Controller的代碼過于臃腫
MVC – 變種
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;
}
優點：對Controller進行瘦身，將View內部的細節封裝起來了，外界不知道View內部的具體實現
缺點：View依賴于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;
// 創建View
TestView *testView = [[TestView alloc] init];
testView.frame = CGRectMake(100, 100, 100, 150);
[controller.view addSubview:testView];
// 加載模型數據
TestModel *model = [[TestModel alloc] init];
model.title = @"QQ";
model.imageName = @"QQ";
// 賦值數據
[testView setName:model.title andImage:model.imageName];
}
return self;
}
@end
可以看到跟蘋果的Apple’s MVC 很相似，多了一個 Presenter 模塊，取代了Controller中轉粘合劑的位置。Presenter本身與當前的ViewController中的生命周期并無關聯,作為業務處理層,個人覺得稱MVCP更合適
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<NSKeyValueChangeKey,id> * _Nonnull change) {
waekSelf.nameLabel.text = change[NSKeyValueChangeNewKey];
}];
[self.KVOController observe:viewModel keyPath:@"imageName" options:NSKeyValueObservingOptionNew block:^(id _Nullable observer, id _Nonnull object, NSDictionary<NSKeyValueChangeKey,id> * _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() <TestViewDelegate>
@property (copy, nonatomic) NSString *title;
@property (copy, nonatomic) NSString *imageName;
@end
@implementation TestViewModel
- (instancetype)initWithController:(UIViewController *)controller
{
if (self = [super init]) {
// 創建View
TestView *testView = [[TestView alloc] init];
testView.frame = CGRectMake(100, 100, 100, 150);
testView.viewModel = self;
[controller.view addSubview:testView];
// 加載模型數據
TestModel *model = [[TestModel alloc] init];
model.title = @"QQ";
model.imageName = @"QQ";
// 設置數據
self.title = model.title;
self.imageName = model.imageName;
}
return self;
}
在MVP的基礎上，將P改成與V雙向綁定的VM就變成了MVVM,個人覺得稱為MVCVM更合適 View <-> C <-> ViewModel <-> Model
KVO監聽屬性是用的Facebook的開源框架 KVOController https://github.com/facebookarchive/KVOController
三層架構、四層架構
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{
// 調用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;
{
// 先取出本地數據
// [DBTool loadLocalData....];
// 如果沒有本地數據，就加載網絡數據
// [HTTPTool GET:@"xxxx" params:nil success:^(id result) {
// success(array);
// } failure:failure];
}
@end
設計模式
設計模式（Design Pattern）
是一套被反復使用、代碼設計經驗的總結
使用設計模式的好處是：可重用代碼、讓代碼更容易被他人理解、保證代碼可靠性
一般與編程語言無關，是一套比較成熟的編程思想
設計模式可以分為三大類
創建型模式：對象實例化的模式，用于解耦對象的實例化過程
單例模式、工廠方法模式，等等結構型模式：把類或對象結合在一起形成一個更大的結構
代理模式、適配器模式、組合模式、裝飾模式，等等行為型模式：類或對象之間如何交互，及劃分責任和算法
觀察者模式、命令模式、責任鏈模式，等等
