在我们使用传统的MVC设计模式的时候,通常写着写着C中的代码就会变得又多又乱,今天通过一个简单的实例来了解MVP设计模式(即Model,View,Present).
Present负责了Model和View之间的交流和沟通,相当于是他们两个之间的 桥梁,并且在Present中可以承担一些原来在Controller中的逻辑,比如数据请求等,这样在Controller中只是实现简单的依赖设置和生命周期以及代理方法即可.具体事例如下:
首先创建Model层
//只是简单的设置一个`content`属性
.h
@interface MVPModel : NSObject
@property(nonatomic,strong)NSString *content;
@end
.m
@implementation MVPModel
@end
创建View层
.h
//代理
@protocol MVPViewDelegate <NSObject>
-(void)btClicked:(UIButton *)bt;
@end
@interface MVPView : UIView
@property(nonatomic,strong)UILabel *label;
@property(nonatomic,strong)UIButton *bt;
@property(nonatomic,weak)id<MVPViewDelegate>delegate;
@end
.m
//重写初始化方法
-(instancetype)initWithFrame:(CGRect)frame{
self = [super initWithFrame:frame];
if (self) {
[self makeUI];
}
return self;
}
//页面布局
-(void)makeUI{
self.backgroundColor = [UIColor whiteColor];
self.label = [[UILabel alloc]initWithFrame:CGRectMake(self.frame.size.width/2-80, 100, 160, 50)];
_label.textAlignment = NSTextAlignmentCenter;
_label.backgroundColor = [UIColor lightGrayColor];
_label.layer.cornerRadius = 5;
_label.layer.masksToBounds = YES;
[self addSubview:_label];
self.bt = [UIButton buttonWithType:UIButtonTypeSystem];
_bt.frame = CGRectMake(self.frame.size.width/2-80, 200, 160, 50);
_bt.backgroundColor = [UIColor lightGrayColor];
_bt.layer.cornerRadius = 5;
[_bt setTitle:@"点我" forState:UIControlStateNormal];
[_bt addTarget:self action:@selector(btAction:) forControlEvents:UIControlEventTouchUpInside];
[self addSubview:_bt];
}
//点击方法
-(void)btAction:(UIButton *)bt{
[_delegate btClicked:bt];
}
创建Present
.h
@interface Presenter : NSObject <MVPViewDelegate>
@property(nonatomic,strong)MVPModel *mvpModel;
@property(nonatomic,strong)MVPView *mvpView;
-(void)presentViewWithContent;
@end
.m
-(void)presentViewWithContent{
self.mvpModel.content = @"123";
self.mvpView.label.text = self.mvpModel.content;
self.mvpView.delegate = self;
}
#pragma mark - 代理
-(void)btClicked:(UIButton *)bt{
self.mvpModel.content = @"123456";
self.mvpView.label.text = self.mvpModel.content;
}
在控制器中使用
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.mvpView = [[MVPView alloc]initWithFrame:self.view.bounds];
[self.view addSubview:_mvpView];
self.mvpModel = [[MVPModel alloc]init];
self.presenter = [[Presenter alloc]init];
self.presenter.mvpModel = _mvpModel;
self.presenter.mvpView = _mvpView;
[self.presenter presentViewWithContent];
}
大概的思路和原理就是这样的,可以根据自己的实际需求在此基础上进行整改即可.
