代理设计模式——实现九宫格界面

来源：互联网发布：苹果无线鼠标软件编辑：程序博客网时间：2024/06/02 21:19

1.先实现一个实例，然后用代理设计模式实现这个实例，并比较代理设计模式的好处

1.1程序实现效果如图：

1.2.实现步骤

1.2.1搭建界面

MJAppView.xib界面：

1.2.2 plist文件

1.2.3代码

//  MJApp.h//  模型类:用来存放数据的类#import <Foundation/Foundation.h>/** copy : NSString strong: 一般对象 weak: UI控件 assign:基本数据类型 */@interface MJApp : NSObject/** *  名称 */@property (nonatomic, copy) NSString *name;/** *  图标 */@property (nonatomic, copy) NSString *icon;/** *  通过字典来初始化模型对象 * *  @param dict 字典对象 * *  @return 已经初始化完毕的模型对象 */- (instancetype)initWithDict:(NSDictionary *)dict;+ (instancetype)appWithDict:(NSDictionary *)dict;@end

////  MJApp.m#import "MJApp.h"@implementation MJApp- (instancetype)initWithDict:(NSDictionary *)dict{    if (self = [super init]) {        self.name = dict[@"name"];        self.icon = dict[@"icon"];    }    return self;}+ (instancetype)appWithDict:(NSDictionary *)dict{    return [[self alloc] initWithDict:dict];}@end

////  MJAppView.h#import <UIKit/UIKit.h>@class MJApp;@interface MJAppView : UIView/** *  模型数据 */@property (nonatomic, strong) MJApp *app;+ (instancetype)appView;/** *  通过模型数据来创建一个view */+ (instancetype)appViewWithApp:(MJApp *)app;@end

////  MJAppView.m#import "MJAppView.h"#import "MJApp.h"@interface MJAppView()@property (weak, nonatomic) IBOutlet UIImageView *iconView;@property (weak, nonatomic) IBOutlet UILabel *nameLabel;- (IBAction)download:(UIButton *)sender;@end@implementation MJAppView+ (instancetype)appViewWithApp:(MJApp *)app{    NSBundle *bundle = [NSBundle mainBundle];    // 读取xib文件(会创建xib中的描述的所有对象,并且按顺序放到数组中返回)    NSArray *objs = [bundle loadNibNamed:@"MJAppView" owner:nil options:nil];    MJAppView *appView = [objs lastObject];    appView.app = app;    return appView;}+ (instancetype)appView{    return [self appViewWithApp:nil];}- (void)setApp:(MJApp *)app{    _app = app;        // 1.设置图标    self.iconView.image = [UIImage imageNamed:app.icon];        // 2.设置名称    self.nameLabel.text = app.name;}/** *  下载 */- (IBAction)download:(UIButton *)btn {    // 1.让按钮失效(文字变为"已下载")    btn.enabled = NO;        // 2.显示下载成功的信息("成功下载xxx")    UILabel *label = [[UILabel alloc] init];    label.text = [NSString stringWithFormat:@"成功下载%@", self.app.name];    label.font = [UIFont systemFontOfSize:12];    label.textAlignment = NSTextAlignmentCenter;    label.textColor = [UIColor whiteColor];    label.backgroundColor = [UIColor blackColor];    label.frame = CGRectMake(0, 0, 150, 25);    label.center = CGPointMake(160, 240);    label.alpha = 0.0;        // 巧妙利用控件的尺寸和圆角半径,能产生一个圆    label.layer.cornerRadius = 5;    // 超出主层边界的内容统统剪掉//    label.layer.masksToBounds = YES;    label.clipsToBounds = YES;        [self.superview addSubview:label];        // 3.动画    [UIView animateWithDuration:1.0 animations:^{        label.alpha = 0.5;    } completion:^(BOOL finished) {        [UIView animateWithDuration:1.0 delay:1.0 options:UIViewAnimationOptionCurveLinear animations:^{            label.alpha = 0.0;        } completion:^(BOOL finished) {            [label removeFromSuperview];        }];    }];}@end

////  MJViewController.m#import "MJViewController.h"#import "MJApp.h"#import "MJAppView.h"@interface MJViewController ()/** 存放应用信息 */@property (nonatomic, strong) NSArray *apps;@end@implementation MJViewController- (void)viewDidLoad{    [super viewDidLoad];        // 添加应用信息        // 0.总列数(一行最多3列)    int totalColumns = 3;        // 1.应用的尺寸    CGFloat appW = 85;    CGFloat appH = 90;        // 2.间隙 = (控制器view的宽度 - 3 * 应用宽度) / 4    CGFloat marginX = (self.view.frame.size.width - totalColumns * appW) / (totalColumns + 1);    CGFloat marginY = 15;        // 3.根据应用个数创建对应的框框(index 0 ~ 11)    for (int index = 0; index<self.apps.count; index++) {        // 3.1.创建view        MJAppView *appView = [MJAppView appViewWithApp:self.apps[index]];                // 3.2.添加view        [self.view addSubview:appView];                // 3.3.设置frame        int row = index / totalColumns;        int col = index % totalColumns;        // 计算x和y        CGFloat appX = marginX + col * (appW + marginX);        CGFloat appY = 30 + row * (appH + marginY);        appView.frame = CGRectMake(appX, appY, appW, appH);                // 3.4.设置数据//        appView.app = self.apps[index];    }}- (NSArray *)apps{    if (_apps == nil) {        // 初始化                // 1.获得plist的全路径        NSString *path = [[NSBundle mainBundle] pathForResource:@"app.plist" ofType:nil];                // 2.加载数组        NSArray *dictArray = [NSArray arrayWithContentsOfFile:path];                // 3.将dictArray里面的所有字典转成模型对象,放到新的数组中        NSMutableArray *appArray = [NSMutableArray array];        for (NSDictionary *dict in dictArray) {            // 3.1.创建模型对象            MJApp *app = [MJApp appWithDict:dict];                        // 3.2.添加模型对象到数组中            [appArray addObject:app];        }                // 4.赋值        _apps = appArray;    }    return _apps;}@end

2.代理设计模式

2.1背景

分析上面的实现代码会发现 xib文件和控制器耦合性太强，假如某天xib里面的文件改变了，那么控制器就必须跟着改变……

所以需要让xib和控制器隔离开来

2.2代码

模型类

//  MJApp.h//  模型类:用来存放数据的类#import <Foundation/Foundation.h>/** copy : NSString strong: 一般对象 weak: UI控件 assign:基本数据类型 */@interface MJApp : NSObject/** *  名称 */@property (nonatomic, copy) NSString *name;/** *  图标 */@property (nonatomic, copy) NSString *icon;/** *  通过字典来初始化模型对象 * *  @param dict 字典对象 * *  @return 已经初始化完毕的模型对象 */- (instancetype)initWithDict:(NSDictionary *)dict;+ (instancetype)appWithDict:(NSDictionary *)dict;@end

////  MJApp.m#import "MJApp.h"@implementation MJApp- (instancetype)initWithDict:(NSDictionary *)dict{    if (self = [super init]) {        self.name = dict[@"name"];        self.icon = dict[@"icon"];    }    return self;}+ (instancetype)appWithDict:(NSDictionary *)dict{    return [[self alloc] initWithDict:dict];}@end

////  MJAppView.h#import <UIKit/UIKit.h>@class MJApp, MJAppView;// 声明一个协议@protocol MJAppViewDelegate <NSObject>@optional- (void)appViewClickedDownloadButton:(MJAppView *)appView;@end// 耦合性@interface MJAppView : UIView/** *  代理 */@property (nonatomic, weak) id<MJAppViewDelegate> delegate;//@property (weak, nonatomic) IBOutlet UIButton *downloadBtn;//@property (nonatomic, weak) UIView *vcView;/** *  模型数据 */@property (nonatomic, strong) MJApp *app;+ (instancetype)appView;/** *  通过模型数据来创建一个view */+ (instancetype)appViewWithApp:(MJApp *)app;@end

////  MJAppView.m#import "MJAppView.h"#import "MJApp.h"@interface MJAppView()@property (weak, nonatomic) IBOutlet UIImageView *iconView;@property (weak, nonatomic) IBOutlet UILabel *nameLabel;- (IBAction)download:(UIButton *)sender;@end@implementation MJAppView+ (instancetype)appViewWithApp:(MJApp *)app{    NSBundle *bundle = [NSBundle mainBundle];    // 读取xib文件(会创建xib中的描述的所有对象,并且按顺序放到数组中返回)    NSArray *objs = [bundle loadNibNamed:@"MJAppView" owner:nil options:nil];    MJAppView *appView = [objs lastObject];    appView.app = app;    return appView;}+ (instancetype)appView{    return [self appViewWithApp:nil];}- (void)setApp:(MJApp *)app{    _app = app;        // 1.设置图标    self.iconView.image = [UIImage imageNamed:app.icon];  //self是指MJAppview        // 2.设置名称    self.nameLabel.text = app.name;}/** *  下载 */- (IBAction)download:(UIButton *)btn {    // 1.让按钮失效(文字变为"已下载")    btn.enabled = NO;        // 2.通知代理//    [self.delegate appViewClickedDownloadButton:self];    if ([self.delegate respondsToSelector:@selector(appViewClickedDownloadButton:)]) {        [self.delegate appViewClickedDownloadButton:self];    }}@end

////  MJViewController.m#import "MJViewController.h"#import "MJApp.h"#import "MJAppView.h"@interface MJViewController () <MJAppViewDelegate>/** 存放应用信息 */@property (nonatomic, strong) NSArray *apps;@end@implementation MJViewController- (void)viewDidLoad{    [super viewDidLoad];        // 添加应用信息        // 0.总列数(一行最多3列)    int totalColumns = 3;        // 1.应用的尺寸    CGFloat appW = 85;    CGFloat appH = 90;        // 2.间隙 = (控制器view的宽度 - 3 * 应用宽度) / 4    CGFloat marginX = (self.view.frame.size.width - totalColumns * appW) / (totalColumns + 1);    CGFloat marginY = 15;        // 3.根据应用个数创建对应的框框(index 0 ~ 11)    for (int index = 0; index<self.apps.count; index++) {        // 3.1.创建view        MJAppView *appView = [MJAppView appViewWithApp:self.apps[index]];                appView.delegate = self;        //        appView.downloadBtn.tag = index;//        [appView.downloadBtn addTarget:self action:@selector(download:) forControlEvents:UIControlEventTouchUpInside];//        appView.vcView = self.view;                // 3.2.添加view        [self.view addSubview:appView];                // 3.3.设置frame        int row = index / totalColumns;        int col = index % totalColumns;        // 计算x和y        CGFloat appX = marginX + col * (appW + marginX);        CGFloat appY = 30 + row * (appH + marginY);        appView.frame = CGRectMake(appX, appY, appW, appH);                // 3.4.设置数据//        appView.app = self.apps[index];    }}/** *  当点击下载按钮时就会调用 */- (void)appViewClickedDownloadButton:(MJAppView *)appView{    // 1.取出模型    MJApp *app = appView.app;        // 2.添加标签    UILabel *label = [[UILabel alloc] init];    label.text = [NSString stringWithFormat:@"成功下载%@", app.name];  //    label.font = [UIFont systemFontOfSize:12];    label.textAlignment = NSTextAlignmentCenter;    label.textColor = [UIColor whiteColor];    label.backgroundColor = [UIColor blackColor];    label.frame = CGRectMake(0, 0, 150, 25);    label.center = CGPointMake(160, 240);    label.alpha = 0.0;    label.layer.cornerRadius = 5; //要设置一个控件的圆角就要设置其图层 （layer就叫图层   cornerRadius叫圆角半径     //lable.layer.masksToBounds = YES  //这个lable的图层要跟随其边界来展示  超出其边界的就要减掉 label.clipsToBounds = YES;  //减掉子层那些找出边界的部分 ，这行代码和上面一行代码效果一样    [self.view addSubview:label];          // 3.动画  （alpha花1秒钟时间从0慢慢变到0.5，再用1秒钟时间从    [UIView animateWithDuration:1.0 animations:^{        label.alpha = 0.5;    } completion:^(BOOL finished) {        [UIView animateWithDuration:1.0 delay:1.0 options:UIViewAnimationOptionCurveLinear animations:^{            label.alpha = 0.0;        } completion:^(BOOL finished) {            [label removeFromSuperview];        }];    }];}- (NSArray *)apps{    if (_apps == nil) {        // 初始化                // 1.获得plist的全路径        NSString *path = [[NSBundle mainBundle] pathForResource:@"app.plist" ofType:nil];                // 2.加载数组        NSArray *dictArray = [NSArray arrayWithContentsOfFile:path];                // 3.将dictArray里面的所有字典转成模型对象,放到新的数组中        NSMutableArray *appArray = [NSMutableArray array];        for (NSDictionary *dict in dictArray) {            // 3.1.创建模型对象            MJApp *app = [MJApp appWithDict:dict];                        // 3.2.添加模型对象到数组中            [appArray addObject:app];        }                // 4.赋值        _apps = appArray;    }    return _apps;}@end

3.Delegate

3.1Delegate的使用场合

对象A内部发生了一些事情,想通知对象B

对象B想监听对象A内部发生了什么事情

对象A想在自己的方法内部调用对象B的某个方法,并且对象A不能对对象B有耦合依赖

对象A想传递数据给对象B

……

以上情况,结果都一样:对象B是对象A的代理(delegate)

3.2使用delegate的步骤

先搞清楚谁是谁的代理(delegate)

定义代理协议,协议名称的命名规范:控件类名 + Delegate

定义代理方法
代理方法一般都定义为@optional
代理方法名都以控件名开头
代理方法至少有1个参数,将控件本身传递出去

设置代理(delegate)对象 (比如myView.delegate = xxxx;)
代理对象遵守协议
代理对象实现协议里面该实现的方法

在恰当的时刻调用代理对象(delegate)的代理方法,通知代理发生了什么事情
(在调用之前判断代理是否实现了该代理方法)