[iOS基础控件 - 5.5] 代理设计模式 (基于”APP列表"练习)

A.概述

     在"[iOS基础控件 - 4.4] APP列表 进一步封装，初见MVC模式”上进一步改进，给“下载”按钮加上效果、功能

     1.按钮点击后，显示为“已下载”，并且不可以再按

     2.在屏幕中间弹出一个消息框，通知消息“xx已经被安装”，慢慢消失

     3.消息框样式为圆角半透明

B.不使用代理模式，使用app空间组和主View之间的父子View关系

1.在主View中创建一个消息框

主View控制器：ViewController.m

  // 创建下载成功消息框
     CGFloat labelWidth = ;
     CGFloat labelHeight = ;
     CGFloat labelX = (self.view.frame.size.width - labelWidth) / ;
     CGFloat labelY = (self.view.frame.size.height - labelHeight) / ;
     UILabel *successMsgLabel = [[UILabel alloc] initWithFrame:CGRectMake(labelX, labelY, labelWidth, labelHeight)];

     // 设置圆角矩形样式
     successMsgLabel.layer.cornerRadius = 10.0;
     successMsgLabel.layer.masksToBounds = YES;

     // 设置全透明隐藏
     successMsgLabel.alpha = ;

     successMsgLabel.textColor = [UIColor whiteColor];
     successMsgLabel.backgroundColor = [UIColor grayColor];
     [successMsgLabel setTextAlignment:NSTextAlignmentCenter];
     successMsgLabel.tag = ;

     [self.view addSubview:successMsgLabel];

2.直接在app空间组的控制器中操作消息框，加入到父控件（主View）

app控件组View：AppView.m

 // 点击下载按钮
 - (IBAction)onDownloadButtonClick {
     // 更改“下载”按钮样式
     [self.downloadButton setTitle:@"已下载" forState:UIControlStateDisabled];
     self.downloadButton.enabled = NO;

     // 拿到消息框
     UILabel *successMsgLabel = [self.superview viewWithTag:];
     successMsgLabel.text = [NSString stringWithFormat:@"成功安装了%@", self.appData.name];
     successMsgLabel.alpha = 0.7;

     // 使用动画
     [UIView beginAnimations:nil context:nil];
     [UIView setAnimationDuration:];
     successMsgLabel.alpha = ;
     [UIView commitAnimations];
 }

缺点：view的父子关系规定了这两个view的层次关系，依赖性、耦合性太强，导致各个view都不能*修改

C.不使用代理模式，在app控件组的view中将主View作为一个成员

1.在控件组AppView中创建主View的引用

控件组 AppView.h

 // 存储主View的引用
 @property (nonatomic, weak) UIView *vcView;

2.在主View逐个加载控件组的时候，设置主View的引用

ViewController.m

  for (int index=; index<self.apps.count; index++) {
         App *appData = self.apps[index];

         // 1.创建View
         AppView *appView = [AppView appViewWithApp:appData];

         // 2.定义每个app的位置、尺寸
         CGFloat appX = marginX + column * (marginX + APP_WIDTH);
         CGFloat appY = marginY + row * (marginY + APP_HEIGHT);
         appView.frame = CGRectMake(appX, appY, APP_WIDTH, APP_HEIGHT);

         // 设置每个app控件view的主view引用
         appView.vcView = self.view;

         // 3.加入此app信息到总view
         [self.view addSubview:appView];

         column++;
         if (column == appColumnCount) {
             column = ;
             row++;
         }

3.控件组AppView使用主View引用代替父控件引用

AppView.m

 // 点击下载按钮
 - (IBAction)onDownloadButtonClick {
     // 更改“下载”按钮样式
     [self.downloadButton setTitle:@"已下载" forState:UIControlStateDisabled];
     self.downloadButton.enabled = NO;

     // 创建消息框
     UILabel *successMsgLabel = [self.vcView viewWithTag:];
     successMsgLabel.text = [NSString stringWithFormat:@"成功安装了%@", self.appData.name];
     successMsgLabel.alpha = 0.7;

     // 使用动画
     [UIView beginAnimations:nil context:nil];
     [UIView setAnimationDuration:];
     successMsgLabel.alpha = ;
     [UIView commitAnimations];
 }

缺点：控件组AppView的下载事件中取得控制器来弹出消息框，还是依赖于主View，耦合性强

D.暴露控件组AppView的“下载”按钮，在主控制器中编写“下载”事件方法，绑定方法

1.AppView暴露“下载”按钮控件给外部

AppView.h

 // 将“下载”按钮控件移到 .h 文件中暴露
 @property (weak, nonatomic) IBOutlet UIButton *downloadButton;

2.在控制器中编写“下载”单击事件方法

ViewController.m

 // 控制器创建“下载”按钮点击事件
 - (IBAction)onAppViewDownloadButtonClick:(UIButton *) downloadButton {
     // 更改“下载”按钮样式
     [downloadButton setTitle:@"已下载" forState:UIControlStateDisabled];
     downloadButton.enabled = NO;

     // 创建消息框
     UILabel *successMsgLabel = [self.view viewWithTag:];

     App *app = self.apps[downloadButton.tag];
     successMsgLabel.text = [NSString stringWithFormat:@"成功安装了%@", app.name];
     successMsgLabel.alpha = 0.7;

     // 使用动画
     [UIView beginAnimations:nil context:nil];
     [UIView setAnimationDuration:];
     successMsgLabel.alpha = ;
     [UIView commitAnimations];
 }

 @end

3.给每个AppView的“下载”按钮绑定方法

  for (int index=; index<self.apps.count; index++) {
         App *appData = self.apps[index];

         // 1.创建View
         AppView *appView = [AppView appViewWithApp:appData];

         // 2.定义每个app的位置、尺寸
         CGFloat appX = marginX + column * (marginX + APP_WIDTH);
         CGFloat appY = marginY + row * (marginY + APP_HEIGHT);
         appView.frame = CGRectMake(appX, appY, APP_WIDTH, APP_HEIGHT);

         // 存储每个AppView对应的AppData数据索引在tag中
         appView.downloadButton.tag = index;

         // 绑定每个AppView中的“下载”按钮点击事件
         [appView.downloadButton addTarget:self action:@selector(onAppViewDownloadButtonClick:) forControlEvents:UIControlEventTouchUpInside];

         // 3.加入此app信息到总view
         [self.view addSubview:appView];

         column++;
         if (column == appColumnCount) {
             column = ;
             row++;
         }
     }

缺点：依赖于AppView暴露的“下载”按钮，不能被修改

E.代理模式

1.原则：谁拥有资源，谁调用

     添加label到控制器的逻辑：控制器来做

     当点击“下载”按钮的时候，控件组AppView的按钮点击事件应该通知控制器，要执行添加label到控制器view的操作

     控制器监听控件组AppView的下载按钮的点击

1.声明代理

AppView.h

 // 定义代理的协议
 @protocol AppViewDelegate <NSObject>
 // “下载”按钮被点击事件
 @optional
 - (void) appViewClickedDownloadButton:(AppView *) appView;
 @end

2.在AppView中创建代理引用

AppView.h

 @interface AppView : UIView
 // 代理
 @property(nonatomic, weak) id<AppViewDelegate> delegate;
 ...
 @end

3.控制器遵守AppViewDelegate，使其拥有称为代理的资格

 ViewController.m
 @interface ViewController () <AppViewDelegate>
 ...
 @end

4.实现代理方法

ViewController.m

 // “下载”按钮点击的代理方法
 - (void)appViewClickedDownloadButton:(AppView *)appView {
     // 创建下载成功消息框
     CGFloat labelWidth = ;
     CGFloat labelHeight = ;
     CGFloat labelX = (self.view.frame.size.width - labelWidth) / ;
     CGFloat labelY = (self.view.frame.size.height - labelHeight) / ;
     UILabel *successMsgLabel = [[UILabel alloc] initWithFrame:CGRectMake(labelX, labelY, labelWidth, labelHeight)];

     // 设置圆角矩形样式
     successMsgLabel.layer.cornerRadius = 10.0;
     successMsgLabel.layer.masksToBounds = YES;

     // 设置全透明隐藏
     successMsgLabel.alpha = ;

     successMsgLabel.textColor = [UIColor whiteColor];
     successMsgLabel.backgroundColor = [UIColor grayColor];
     [successMsgLabel setTextAlignment:NSTextAlignmentCenter];

     successMsgLabel.text = [NSString stringWithFormat:@"成功安装了%@", appView.appData.name];
     successMsgLabel.alpha = 0.7;

     // 使用动画
     [UIView beginAnimations:nil context:nil];
     [UIView setAnimationDuration:];
     successMsgLabel.alpha = ;
     [UIView commitAnimations];

     [self.view addSubview:successMsgLabel];
 }

5.给每一个AppView设置代理

ViewController.m

   for (int index=; index<self.apps.count; index++) {
         App *appData = self.apps[index];

         // 1.创建View
         AppView *appView = [AppView appViewWithApp:appData];

         // 2.定义每个app的位置、尺寸
         CGFloat appX = marginX + column * (marginX + APP_WIDTH);
         CGFloat appY = marginY + row * (marginY + APP_HEIGHT);
         appView.frame = CGRectMake(appX, appY, APP_WIDTH, APP_HEIGHT);

         // 设置代理
         appView.delegate = self;

         // 3.加入此app信息到总view
         [self.view addSubview:appView];

         column++;
         if (column == appColumnCount) {
             column = ;
             row++;
         }
     }

6.点击“下载”按钮的时候，通知代理

AppView.m

 // 点击下载按钮
 - (IBAction)onDownloadButtonClick {
     // 更改“下载”按钮样式
     [self.downloadButton setTitle:@"已下载" forState:UIControlStateDisabled];
     self.downloadButton.enabled = NO;

     // 通知代理
     // 检查是否实现了代理方法
     if ([self.delegate respondsToSelector:@selector(appViewClickedDownloadButton:)]) {
         [self.delegate appViewClickedDownloadButton:self];
     }
 }

主要代码:

Model:

 App.h
 //
 //  App.h
 //  01-应用管理
 //
 //  Created by hellovoidworld on 14/11/25.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import <Foundation/Foundation.h>

 @interface App : NSObject

 /**
 copy : NSString
 strong: 一般对象
 weak: UI控件
 assign: 基本数据类型
 */

 /**
 名称
 */
 @property(nonatomic, copy) NSString *name;

 /**
 图标
 */
 @property(nonatomic, copy) NSString *icon;

 /**
 自定义构造方法
 通过字典来初始化模型对象
 */
 - (instancetype) initWithDictionary:(NSDictionary *) dictionary;

 + (instancetype) appWithDictionary:(NSDictionary *) dictionary;

 @end

App.m

 //
 //  App.m
 //  01-应用管理
 //
 //  Created by hellovoidworld on 14/11/25.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import "App.h"

 #define ICON_KEY @"icon"
 #define NAME_KEY @"name"

 @implementation App

 - (instancetype) initWithDictionary:(NSDictionary *) dictionary {
     if (self = [super init]) {
         self.name = dictionary[NAME_KEY];
         self.icon = dictionary[ICON_KEY];
     }

     return self;
 }

 + (instancetype) appWithDictionary:(NSDictionary *) dictionary {
     // 使用self代表类名代替真实类名，防止子类调用出错
     return [[self alloc] initWithDictionary:dictionary];
 }

 @end

View:

 AppView.h
 //
 //  AppView.h
 //  01-应用管理
 //
 //  Created by hellovoidworld on 14/11/25.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import <UIKit/UIKit.h>

 @class App, AppView;

 // 定义代理的协议
 @protocol AppViewDelegate <NSObject>
 // “下载”按钮被点击事件
 @optional
 - (void) appViewClickedDownloadButton:(AppView *) appView;
 @end

 @interface AppView : UIView

 // 代理
 @property(nonatomic, weak) id<AppViewDelegate> delegate;

 // 在Controller和View之间传输的Model数据
 @property(nonatomic, strong) App *appData;

 // 自定义将Model数据加载到View的构造方法
 - (instancetype) initWithApp:(App *) appData;
 // 自定义构造的类方法
 + (instancetype) appViewWithApp:(App *) appData;
 // 返回一个不带Model数据的类构造方法
 + (instancetype) appView;

 @end

AppView.m

 //
 //  AppView.m
 //  01-应用管理
 //
 //  Created by hellovoidworld on 14/11/25.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import "AppView.h"
 #import "App.h"

 // 封装私有属性
 @interface AppView()

 // 封装View中的控件，只允许自己访问
 @property (weak, nonatomic) IBOutlet UIImageView *iconView;
 @property (weak, nonatomic) IBOutlet UILabel *nameLabel;
 @property (weak, nonatomic) IBOutlet UIButton *downloadButton;

 - (IBAction)onDownloadButtonClick;

 @end

 @implementation AppView

 - (void)setAppData:(App *)appData {
     // 1.赋值Medel成员
     _appData = appData;

     // 2.设置图片
     self.iconView.image = [UIImage imageNamed:appData.icon];
     // 3.设置名字
     self.nameLabel.text = appData.name;
 }

 // 自定义将Model数据加载到View的构造方法
 - (instancetype) initWithApp:(App *) appData {
     // 1.从NIB取得控件
     UINib *nib = [UINib nibWithNibName:@"app" bundle:[NSBundle mainBundle]];
     NSArray *viewArray = [nib instantiateWithOwner:nil options:nil];
     AppView *appView = [viewArray lastObject];

     // 2.加载Model
     appView.appData = appData;

     return appView;
 }

 // 自定义构造的类方法
 + (instancetype) appViewWithApp:(App *) appData {
     return [[self alloc] initWithApp:appData];
 }

 // 返回一个不带Model数据的类构造方法
 + (instancetype) appView {
     return [self appViewWithApp:nil];
 }

 // 点击下载按钮
 - (IBAction)onDownloadButtonClick {
     // 更改“下载”按钮样式
     [self.downloadButton setTitle:@"已下载" forState:UIControlStateDisabled];
     self.downloadButton.enabled = NO;

     // 通知代理
     // 检查是否实现了代理方法
     if ([self.delegate respondsToSelector:@selector(appViewClickedDownloadButton:)]) {
         [self.delegate appViewClickedDownloadButton:self];
     }
 }

 @end

Controller:

ViewController.m

 //
 //  ViewController.m
 //  01-应用管理
 //
 //  Created by hellovoidworld on 14/11/24.
 //  Copyright (c) 2014年 hellovoidworld. All rights reserved.
 //

 #import "ViewController.h"
 #import "App.h"
 #import "AppView.h"

 #define ICON_KEY @"icon"
 #define NAME_KEY @"name"
 #define APP_WIDTH 85
 #define APP_HEIGHT 90
 #define MARGIN_HEAD 20
 #define ICON_WIDTH 50
 #define ICON_HEIGHT 50
 #define NAME_WIDTH APP_WIDTH
 #define NAME_HEIGHT 20
 #define DOWNLOAD_WIDTH (APP_WIDTH - 20)
 #define DOWNLOAD_HEIGHT 20

 @interface ViewController () <AppViewDelegate>

 /** 存放应用信息 */
 @property(nonatomic, strong) NSArray *apps; // 应用列表

 @end

 @implementation ViewController

 - (void)viewDidLoad {
     [super viewDidLoad];
     // Do any additional setup after loading the view, typically from a nib.

     [self loadApps];
 }

 - (void)didReceiveMemoryWarning {
     [super didReceiveMemoryWarning];
     // Dispose of any resources that can be recreated.
 }

 #pragma mark 取得应用列表
 - (NSArray *) apps {
     if (nil == _apps) {
         // 1.获得plist的全路径
         NSString *path = [[NSBundle mainBundle] pathForResource:@"app.plist" ofType:nil];

         // 2.加载数据
         NSArray *dictArray  = [NSArray arrayWithContentsOfFile:path];

         // 3.将dictArray里面的所有字典转成模型，放到新数组中
         NSMutableArray *appArray = [NSMutableArray array];
         for (NSDictionary *dict in dictArray) {
             // 3.1创建模型对象
             App *app = [App appWithDictionary:dict];

             // 3.2 添加到app数组中
             [appArray addObject:app];
         }

         _apps = appArray;
     }

     return _apps;
 }

 #pragma mark 加载全部应用列表
 - (void) loadApps {
     int appColumnCount = [self appColumnCount];
     int appRowCount = [self appRowCount];

     CGFloat marginX = (self.view.frame.size.width - APP_WIDTH * appColumnCount) / (appColumnCount + );
     CGFloat marginY = (self.view.frame.size.height - APP_HEIGHT * appRowCount) / (appRowCount + ) + MARGIN_HEAD;

     int column = ;
     int row = ;
     for (int index=; index<self.apps.count; index++) {
         App *appData = self.apps[index];

         // 1.创建View
         AppView *appView = [AppView appViewWithApp:appData];

         // 2.定义每个app的位置、尺寸
         CGFloat appX = marginX + column * (marginX + APP_WIDTH);
         CGFloat appY = marginY + row * (marginY + APP_HEIGHT);
         appView.frame = CGRectMake(appX, appY, APP_WIDTH, APP_HEIGHT);

         // 设置代理
         appView.delegate = self;

         // 3.加入此app信息到总view
         [self.view addSubview:appView];

         column++;
         if (column == appColumnCount) {
             column = ;
             row++;
         }
     }

 }

 #pragma mark 计算列数
 - (int) appColumnCount {
     int count = ;
     count = self.view.frame.size.width / APP_WIDTH;

     if ((int)self.view.frame.size.width % (int)APP_WIDTH == ) {
         count--;
     }

     return count;
 }

 #pragma mark 计算行数
 - (int) appRowCount {
     int count = ;
     count = (self.view.frame.size.height - MARGIN_HEAD) / APP_HEIGHT;

     if ((int)(self.view.frame.size.height - MARGIN_HEAD) % (int)APP_HEIGHT == ) {
         count--;
     }

     return count;
 }

 // “下载”按钮点击的代理方法
 - (void)appViewClickedDownloadButton:(AppView *)appView {
     // 创建下载成功消息框
     CGFloat labelWidth = ;
     CGFloat labelHeight = ;
     CGFloat labelX = (self.view.frame.size.width - labelWidth) / ;
     CGFloat labelY = (self.view.frame.size.height - labelHeight) / ;
     UILabel *successMsgLabel = [[UILabel alloc] initWithFrame:CGRectMake(labelX, labelY, labelWidth, labelHeight)];

     // 设置圆角矩形样式
     successMsgLabel.layer.cornerRadius = 10.0;
     successMsgLabel.layer.masksToBounds = YES;

     // 设置全透明隐藏
     successMsgLabel.alpha = ;

     successMsgLabel.textColor = [UIColor whiteColor];
     successMsgLabel.backgroundColor = [UIColor grayColor];
     [successMsgLabel setTextAlignment:NSTextAlignmentCenter];

     successMsgLabel.text = [NSString stringWithFormat:@"成功安装了%@", appView.appData.name];
     successMsgLabel.alpha = 0.7;

     // 使用动画
     [UIView beginAnimations:nil context:nil];
     [UIView setAnimationDuration:];
     successMsgLabel.alpha = ;
     [UIView commitAnimations];

     [self.view addSubview:successMsgLabel];
 }

 @end