大胖子
做iOS开发的人都会知道，MVC模式下，UIViewController会无比笨重！什么界面显示、代理方法、网络请求、都可以往里面塞。
而MVVM还不是很了解，后续做到在写Demo。
MVP
因此借鉴了做Android的同事的做法：MVP。
如果心急，本文最下面有代码传送门！
M：Model
V：UIViewController(view)
P：Presenter
前两个好理解，那Presenter呢？
个人理解，作为分担UIViewController重担的角色，把UIViewController中的除了界面显示的其他逻辑，都丢进Presenter中。一个UIViewController对应一个Presenter。Presenter在UIViewController中实例化的同时，把UIViewController实例传给Presenter。
那么UIViewController跟Presenter如何交互。
这里我实现了两种方式，一种是协议，一种是Block。不过Block实现起来更加轻巧。不像协议，需要声明一堆方法。
这里我具体写了一个例子，在一个登陆界面，有信息显示Label，账户输入框TextField，密码输入框TextField，登录按钮Button。
按下按钮之后，在Presenter执行类似请求接口进行登录的逻辑。执行登录动作，可能有三种状态，一种是登录中，一种是登录成功，一种是登录失败。那么这三种状态，通过实现协议方法，将各自的数据回传给View。
2.png
下面是文件结构：
1.png
以下是两种实现方式的代码：
使用协议实现数据回传
view：
ViewController.h
#import <UIKit/UIKit.h>
#import "MyPresenter.h"
@interface ViewController : UIViewController
//登录信息显示
@property (weak, nonatomic) IBOutlet UILabel *infoLabel;
//账户输入框
@property (weak, nonatomic) IBOutlet UITextField *accountTextF;
//密码输入框
@property (weak, nonatomic) IBOutlet UITextField *passwordTextF;
@end
ViewController.m
#import "ViewController.h"
@interface ViewController ()<MyPresenterDelegate>{
MyPresenter *presenter;
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
//实例化Presenter对象，将页面的传给Presenter
presenter = [[MyPresenter alloc]initWithViewController:self];
presenter.myPresenterDelegate = self;
}
//登录事件
- (IBAction)MyBtnClick:(UIButton *)sender{
[presenter loginWithAccount:_accountTextF.text password:_passwordTextF.text];
}
#pragma mark -MyPresenterDelegate
-(void)logining:(NSString *)info{
_infoLabel.text = info;
}
-(void)loginSuccess:(NSString *)info{
_infoLabel.text = info;
}
-(void)loginFailure:(NSString *)info{
_infoLabel.text = info;
}
//触摸空白地方，键盘隐藏
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
[_accountTextF resignFirstResponder];
[_passwordTextF resignFirstResponder];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
Presenter
BasePresenter.h
#import <UIKit/UIKit.h>
@interface BasePresenter : NSObject
@property (nonatomic,strong)UIViewController *vc;
-(instancetype)initWithViewController:(UIViewController*)viewC;
@end
BasePresenter.m
#import "BasePresenter.h"
@implementation BasePresenter
-(instancetype)initWithViewController:(UIViewController*)viewC{
self = [super init];
if (self) {
self.vc = viewC;
}
return self;
}
@end
MyPresenter.h
#import "BasePresenter.h"
#import "ViewController.h"
@protocol MyPresenterDelegate<NSObject>//执行完，反馈给界面，传值或者使得界面做出具体操作。
- (void)logining:(NSString*)info;
- (void)loginSuccess:(NSString*)info;
- (void)loginFailure:(NSString*)info;
@end
@interface MyPresenter : BasePresenter
@property(nonatomic,weak)id<MyPresenterDelegate>myPresenterDelegate;
-(void)loginWithAccount:(NSString*)accuout password:(NSString*)password;
@end
#import "MyPresenter.h"
@interface MyPresenter(){
ViewController *viewController;
}
@end
@implementation MyPresenter
-(instancetype)initWithViewController:(UIViewController *)viewC{
self = [super initWithViewController:viewC];
if (self) {
viewController= (ViewController*)self.vc;
}
return self;
}
-(void)loginWithAccount:(NSString*)accuout password:(NSString*)password{
NSLog(@"MyPresenter logining...");
if ([self.myPresenterDelegate respondsToSelector:@selector(logining:)]) {
[self.myPresenterDelegate logining:@"MyPresenter logining..."];
}
//此处模拟网络请求数据,2秒延迟
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
// 2秒后异步执行这里的代码...
// 登录成功或失败，返回数据给界面（实际应用中，此处写：访问登录接口）
if ([accuout isEqualToString:@"vampire"]&&[password isEqualToString:@"123"]) {
if ([self.myPresenterDelegate respondsToSelector:@selector(loginSuccess:)]) {
[self.myPresenterDelegate loginSuccess:@"login success"];
}
}else{
if ([self.myPresenterDelegate respondsToSelector:@selector(loginFailure:)]) {
[self.myPresenterDelegate loginFailure:@"login failure"];
}
}
});
}
@end
使用Block实现数据回传
View
ViewController.h
#import <UIKit/UIKit.h>
#import "MyPresenter.h"
@interface ViewController : UIViewController
//登录信息显示
@property (weak, nonatomic) IBOutlet UILabel *infoLabel;
//账户输入框
@property (weak, nonatomic) IBOutlet UITextField *accountTextF;
//密码输入框
@property (weak, nonatomic) IBOutlet UITextField *passwordTextF;
@end
ViewController.m
#import "ViewController.h"
#define WEAKSELF typeof(self) __weak weakSelf = self;
@interface ViewController (){
MyPresenter *presenter;
}
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
//实例化Presenter对象，将页面的传给Presenter
presenter = [[MyPresenter alloc]initWithViewController:self];
[self loginResult];
}
//登录事件
- (IBAction)MyBtnClick:(UIButton *)sender{
// [presenter loginWithAccount:_accountTextF.text password:_passwordTextF.text];
//方式二：
// WEAKSELF
// [presenter login2WithAccount:_accountTextF.text password:_passwordTextF.text block:^(NSString *info) {
// weakSelf.infoLabel.text = info;
// }];
}
//Block实现
-(void)loginResult{
WEAKSELF
presenter.loginResult = ^(NSString *info){
weakSelf.infoLabel.text = info;
};
}
//触摸空白地方，键盘隐藏
-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
[_accountTextF resignFirstResponder];
[_passwordTextF resignFirstResponder];
}
- (void)didReceiveMemoryWarning {
[super didReceiveMemoryWarning];
// Dispose of any resources that can be recreated.
}
@end
Presenter
BasePresenter文件保持不变。
MyPresenter.h
#import "BasePresenter.h"
#import "ViewController.h"
//因为三种登录状态都是传回一个NSString，所以定义一个通用Block
typedef void (^LoginResult)(NSString *info);
@interface MyPresenter : BasePresenter
@property (nonatomic,strong)LoginResult loginResult;//声明Blokc
-(void)loginWithAccount:(NSString*)accuout password:(NSString*)password;
-(void)login2WithAccount:(NSString*)accuout password:(NSString*)password block:(void(^)(NSString *info))block;
@end
MyPresenter.m
#import "MyPresenter.h"
@interface MyPresenter(){
ViewController *viewController;
}
@end
@implementation MyPresenter
-(instancetype)initWithViewController:(UIViewController *)viewC{
self = [super initWithViewController:viewC];
if (self) {
viewController= (ViewController*)self.vc;
}
return self;
}
-(void)loginWithAccount:(NSString*)accuout password:(NSString*)password{
//Block引用
self.loginResult(@"MyPresenter logining...");
//此处模拟网络请求数据,2秒延迟
__weak typeof(self) weakSelf = self;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
// 2秒后异步执行这里的代码...
// 登录成功或失败，返回数据给界面（实际应用中，此处写：访问登录接口）
if ([accuout isEqualToString:@"vampire"]&&[password isEqualToString:@"123"]) {
weakSelf.loginResult(@"login success");
}else{
weakSelf.loginResult(@"login failure");
}
});
}
//当然Block也可以放到方法上作为参数
-(void)login2WithAccount:(NSString*)accuout password:(NSString*)password block:(void(^)(NSString *info))block{
//Block引用
block(@"MyPresenter logining...");
//此处模拟网络请求数据,2秒延迟
// __weak typeof(self) weakSelf = self;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
// 2秒后异步执行这里的代码...
// 登录成功或失败，返回数据给界面（实际应用中，此处写：访问登录接口）
if ([accuout isEqualToString:@"vampire"]&&[password isEqualToString:@"123"]) {
block(@"login success");
}else{
block(@"login failure");
}
});
}
@end
可以看到以上例子，Block的声明方式是不同的，具体的写法也是不一样的。
小结
通过以上两个例子，可以发现，Presenter使得UIViewController得以解放，很多逻辑可以写到Presenter中。而逻辑的执行结果，需要返回给UIViewController，所以就需要使用协议或者Block。
代码传送门
看懂了的朋友，点个💗吧！么么哒~~~
