1.概念
M: model 模型层: 负责保存数据,继承自NSObject
V: view视图层:负责向用户展示数据, 继承自UIVIew
C: controller控制器层: 负责将model层的数据传递到view层, 继承UIViewController
2. 职责
Model层:负责定义Model的属性
View层:需要持有Model层的引用,在视图初始化的时候添加所有子视图,并重写model属性的setter方法来为子视图填充数据
Controller: 需要获取Model数据,并初始化View,然后将Model赋值给View的model引用, 最后将View添加到self.view上
MVC框架的目的是,尽可能的降低代码的耦合度(低耦合),使的每个类个职责单一化(单一职责),以便更容易的维护.
3.示例代码
1.Model层
#import <Foundation/Foundation.h>
@interface User : NSObject
@property (copy, nonatomic) NSString *name;
@property (copy, nonatomic) NSString *password;
@end
#import "User.h"
@implementation User
@end
2.View层
#import <UIKit/UIKit.h>
#import "User.h"
@interface UserView : UIView
@property (strong, nonatomic) User *user;
@end
#import "UserView.h"
@interface UserView () {
UILabel *nameLabel;
UILabel *passwordLabel;
}
@end
@implementation UserView
// 初始化子视图
- (instancetype)initWithFrame:(CGRect)frame {
if (self = [super initWithFrame:frame]) {
nameLabel = [[UILabel alloc] initWithFrame:CGRectMake(50, 100, 200, 50)];
nameLabel.backgroundColor = [UIColor darkGrayColor];
nameLabel.textColor = [UIColor whiteColor];
[self addSubview:nameLabel];
passwordLabel = [[UILabel alloc] initWithFrame:CGRectMake(50, 300, 200, 50)];
passwordLabel.backgroundColor = [UIColor darkGrayColor];
passwordLabel.textColor = [UIColor whiteColor];
[self addSubview:passwordLabel];
}
return self;
}
// 为子视图填充数据
- (void)setUser:(User *)user {
_user = user;
// 视图层展示的Label数据是从Model中获取的
nameLabel.text = _user.name;
passwordLabel.text = _user.password;
}
@end
3.Controller层
#import "User.h"
#import "UserView.h"
@interface ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
// 1. 模拟从网络或其他位置获取数据
User *userModel = [[User alloc] init];
userModel.name = @"xiaohong";
userModel.password = @"123456";
// 2. 将获取的数据加载到View之上,交给View处理
CGSize screenSize = [UIScreen mainScreen].bounds.size;
UserView *userView = [[UserView alloc] initWithFrame:CGRectMake(0, 0, screenSize.width, screenSize.height)];
userView.user = userModel;
[self.view addSubview:userView];
}
@end