#import <Foundation/Foundation.h>
@interface MVVMModel : NSObject
@property(nonatomic,copy)NSString *name;
@end

#import <Foundation/Foundation.h>
#import "MVVMModel.h"
@interface MVVMViewModel : NSObject
@property(nonatomic,copy)NSString *nameStr;
@property(nonatomic,strong)MVVMModel *model;-(void)setWithModel:(MVVMModel *)model;
-(void)clickChangeName;
@end

#import "MVVMViewModel.h"@implementation MVVMViewModel
-(instancetype)init{if (self = [super init]) {}return self;
}-(void)setWithModel:(MVVMModel *)model{self.model = model;self.nameStr = model.name;
}
-(void)clickChangeName{self.model.name = [NSString stringWithFormat:@"name%d",arc4random()%10];self.nameStr = self.model.name;NSLog(@"%@",self.nameStr);
}
@end

#import <UIKit/UIKit.h>
#import "MVVMViewModel.h"
@interface MVVMView : UIView
-(void)setWithViewModel:(MVVMViewModel *)vm;
@end#import "MVVMView.h"
@interface MVVMView ()@property(nonatomic,strong)MVVMViewModel *vm;
@property(nonatomic,strong)UILabel *label;
@property(nonatomic,strong)UIButton *button;@end
@implementation MVVMView- (instancetype)init
{self = [super init];if (self) {self.backgroundColor = [UIColor whiteColor];self.frame = [UIScreen mainScreen].bounds;self.label = [[UILabel alloc]initWithFrame:CGRectMake(150,100 , 100, 30)];self.label.backgroundColor = [UIColor orangeColor];[self addSubview:_label];self.button = [UIButton new];_button.backgroundColor = [UIColor redColor];[_button setTitle:@"点击" forState:UIControlStateNormal];[_button addTarget:self action:@selector(mvvmClickChangModel) forControlEvents:UIControlEventTouchUpInside];_button.frame = CGRectMake(150, 200, 50, 50);[self addSubview:_button];}return self;
}
- (void)setWithViewModel:(MVVMViewModel *)vm {self.vm = vm;//KVO[self.vm addObserver:self forKeyPath:@"nameStr" options:NSKeyValueObservingOptionOld|NSKeyValueObservingOptionNew context:nil];self.label.text = vm.nameStr;}-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:    (NSDictionary<NSKeyValueChangeKey,id> *)change context:(void *)context{if ([keyPath isEqualToString:@"nameStr"]&&[change objectForKey:NSKeyValueChangeNewKey]) {NSNumber *new = [change objectForKey:NSKeyValueChangeNewKey];self.label.text = [NSString stringWithFormat:@"%@",new];}
}
-(void)mvvmClickChangModel{[self.vm clickChangeName];
}-(void)dealloc{[self.vm removeObserver:self forKeyPath:@"nameStr"];
}
@end

#import "ViewController.h"
#import "MVVMView.h"
#import "MVVMModel.h"
#import "MVVMViewModel.h"@interface ViewController ()
@property (nonatomic, strong) MVVMViewModel * viewModel ;
@end@implementation ViewController
- (void)viewDidLoad {[super viewDidLoad];MVVMView *MView = [MVVMView new];MVVMModel *model = [MVVMModel new];model.name = @"name1";MVVMViewModel *viewModel = [MVVMViewModel new];[self.view addSubview:MView];//*viewModel 作为枢纽 沟通view和model之间关系
    [viewModel setWithModel:model];[MView setWithViewModel:viewModel];
}
@end