iOS架构初探

MVC

MVC是软件行业一个非常经典的架构,因为几乎所有的业务逻辑几乎都可以用这三个类来表示

image.png
两根红线表示Controller 控制view的渲染 也可以修改model
两根绿线表示view采集到的用户数据和用户事件会反馈给Controller view 可以读取model 进而展示自己
demo演示 MVCController 让 MVCView执行打印任务
场景：

• 初始化

- (void)viewDidLoad {
    [super viewDidLoad];

    self.view.backgroundColor = [UIColor whiteColor];
    self.navigationItem.title = @"MVC";
    
    // MVCView 初始化  通过代理传递事件给 MVCController
    self.myView = [[MVCView alloc] initWithFrame:CGRectMake(50, 64, 300, 400)];
    self.myView.delegate = self;
    
    // MVCModel 初始化  实例数据 
    self.paper = [[Paper alloc] init];
    self.paper.content = @"lky";
    
    
    [self.view addSubview:self.myView];
    
    // MVCController 让 MVCView执行打印任务  或者是渲染
    [self printPaper];
    
}

- (void)printPaper{
    [self.myView printOnView:self.paper];
}

• view 可以读取model 进而展示自己

-(void)printOnView:(Paper *)paper
{
    self.paper = paper;
    self.backgroundColor = [UIColor lightGrayColor];
    NSLog(@"%@---MVCView接收到打印任务",paper.content);
}

• view采集到的用户数据和用户事件会反馈给Controller

- (void)btnClick{

    if ([self.delegate respondsToSelector:@selector(onPrintClick)]) {
        [self.delegate onPrintClick];
    }
}

MVP

image.png

从上图可以看出Controller不见了，多了一个Presenter 来处理逻辑关系， 实际上 Controller只对 Presenter 持有引用关系 另外一点是view和model互相都不知道彼此的存在，

• Presenterc同时持有view和model

@interface Presenter : NSObject

@property (nonatomic,strong) MVPView  *mvpView;

@property (nonatomic,strong) MVPModel  *mvpModel;

- (void)printTask;

@end


-(instancetype)init
{
    if (self = [super init]) {
        
        self.mvpModel = [[MVPModel alloc] init];
        self.mvpModel.content = @"line 0";
        
        
        self.mvpView = [[MVPView alloc] init];
        self.mvpView.frame = CGRectMake(0, 100, 300, 400);
        self.mvpView.delegate = self;
    }
    return self;
}

• Controller告诉Presenterc执行打印任务

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.view.backgroundColor = [UIColor whiteColor];
    self.navigationItem.title = @"MVP";
    
    // 创建3个展示器   模型 视图
    self.presenter = [[Presenter alloc] init];
    [self.view addSubview:self.presenter.mvpView];
    
    // 告诉presenter执行打印任务
    [self.presenter printTask];
}

• Presenter执行打印任务 传递的不是model模型 而是model的属性

@implementation Presenter
-(void)printTask
{
    [self.mvpView printOnViewWithContent:self.mvpModel.content];
}

• view响应事件 通知Presenter进行处理 这里view的代理是Presenter

@implementation MVPView
- (void)btnClick{

    if (self.delegate) {
        [self.delegate printDoneClick];
    }
}

• Presenter处理响应事件

@implementation Presenter
#pragma MVPViewDelegate
-(void)printDoneClick{

    int rand = arc4random()%10;
    self.mvpModel.content = [NSString stringWithFormat:@"line %d",rand];
    [self.mvpView printOnViewWithContent:self.mvpModel.content];
}

MVVM

MVVM.png

与 MVC相比可以看出Controller不见了,多出了viewModel类来处理业务逻辑，view与viewModel之间是一个双向绑定的关系,也就是说view会监听viewModel 然后根据viewModel的变化而更新view的UI变化,在view上面如果有事件产生也会反射给viewModel来与Model进行协调处理

• 初始化

@implementation MVVMController

- (void)viewDidLoad {
    [super viewDidLoad];
   
    self.view.backgroundColor = [UIColor whiteColor];
    self.navigationItem.title = @"MVVM";
    
    self.vmView = [[MVVMView alloc] init];
    self.vmView.frame = CGRectMake(20, 100, 300, 400);
    [self.view addSubview:self.vmView];
    
    self.vmModel = [[MVVModel alloc] init];
    self.vmModel.content = @"line 0";
    
    self.vmViewModel = [[MVVMViewModel alloc] init];
    [self.vmViewModel setWithModel:self.vmModel];
    [self.vmView setWithViewModel:self.vmViewModel];

}

• view与viewModel之间建立双向绑定 这里使用FBKVOController,这是一个对KVO进行封装的库

#import "MVVMView.h"
#import "NSObject+FBKVOController.h"

@interface MVVMView ()

@property (nonatomic,strong) UILabel *labelContent;
@property (nonatomic,strong) UIButton *btn;
@property (nonatomic,weak) MVVMViewModel *vmViewModel;

@end

@implementation MVVMView

-(instancetype)init{
    if (self = [super init]) {
        
        self.backgroundColor = [UIColor grayColor];
        
        self.labelContent = [[UILabel alloc] init];
        self.labelContent.backgroundColor = [UIColor whiteColor];
        self.labelContent.frame = CGRectMake(50, 100, 200, 40);
        [self addSubview:self.labelContent];
        
        self.btn = [UIButton buttonWithType:UIButtonTypeCustom];
        self.btn.frame = CGRectMake(80, 300, 80, 40);
        self.btn.backgroundColor = [UIColor lightGrayColor];
        [self.btn setTitle:@"点击" forState:UIControlStateNormal];
        
        [self addSubview:self.btn];
        [self.btn addTarget:self action:@selector(btnClick) forControlEvents:UIControlEventTouchUpInside];
        
    }
    
    return self;
}


- (void)btnClick{
    
    [self.vmViewModel onPrintClick];
}

-(void)setWithViewModel:(MVVMViewModel *)viewModel
{
  __weak typeof(self) weakSelf = self;
  self.vmViewModel = viewModel;
  [self.KVOController observe:viewModel keyPath:@"contentStr" options:NSKeyValueObservingOptionNew | NSKeyValueObservingOptionInitial block:^(id  _Nullable observer, id  _Nonnull object, NSDictionary<NSKeyValueChangeKey,id> * _Nonnull change) {
    
      NSString *newContent = change[NSKeyValueChangeNewKey];
      weakSelf.labelContent.text = newContent;

  }];
}

@end

• ViewModel处理View响应事件

#import "MVVMViewModel.h"
#import "FBKVOController.h"


@interface MVVMViewModel ()

@property (nonatomic,weak) MVVModel *model;

@end

@implementation MVVMViewModel

// 初始化ViewModel
-(void)setWithModel:(MVVModel *)model{

    self.model = model;
    self.contentStr = model.content;
}

// 响应View事件产生
-(void)onPrintClick
{
    int rand = arc4random()%10;
    self.model.content = [NSString stringWithFormat:@"line %d",rand];
    self.contentStr = self.model.content;
}

@end

demo下载地址