外观模式（手动内存）

Login.h

@interface Login : NSObject
-(void)isLogin;
@end

Login.m

#import "Login.h"

@implementation Login
-(void)isLogin
{
    NSLog(@"it is login");
}
@end

Browse.h

@interface Browse : NSObject
-(void)isBrowse;
@end

Browse.m

#import "Browse.h"

@implementation Browse
-(void)isBrowse
{
    NSLog(@"is browse");
}
@end

Download.h

@interface Download : NSObject
-(void)isDownload;
@end

DownLoad.m

#import "Download.h"

@implementation Download
-(void)isDownload
{
    NSLog(@"is doownload");
}
@end

Logout.h

@interface Logout : NSObject
-(void)isLogout;
@end

Logout.m

#import "Logout.h"

@implementation Logout
-(void)isLogout
{
    NSLog(@"is logout");
}
@end

Facade.h

#import "Login.h"
#import "Browse.h"
#import "Download.h"
#import "Logout.h"
@interface Facade : NSObject
{
    Login *_login;
    Browse *_browse;
    Download *_download;
    Logout *_logout;
}
@property(nonatomic,retain)Login *login;
@property(nonatomic,retain)Browse *browse;
@property(nonatomic,retain)Download *download;
@property(nonatomic,retain)Logout *logout;

-(void)control;
@end

Facade.m

#import "Facade.h"

@implementation Facade
-(void)setLogin:(Login *)aLogin
{
    if (_login != aLogin)
    {
        [_login release];
        _login = [aLogin retain];
    }
}
-(Login *)login
{
    return _login;
}

-(void)setBrowse:(Browse *)aBrowse
{
    if (_browse != aBrowse)
    {
        [_browse release];
        _browse = [aBrowse retain];
    }
}
-(Browse *)browse
{
    return _browse;
}

-(void)setDownload:(Download *)aDownload
{
    if (_download != aDownload)
    {
        [_download release];
        _download = [aDownload retain];
    }
}
-(Download *)download
{
    return _download;
}

-(void)setLogout:(Logout *)aLogout
{
    if (_logout != aLogout)
    {
        [_logout release];
        _logout = [aLogout retain];
    }
}
-(Logout *)logout
{
    return _logout;
}

-(id)init
{
    self = [super init];
    if (self)
    {
        Login *l = [[Login alloc] init];
        self.login = l;
        [l release];
        
        Browse *b = [[Browse alloc]init];
        self.browse = b;
        [b release];
        
        Download *d = [[Download alloc]init];
        self.download = d;
        [d release];
        
        Logout *lo = [[Logout alloc]init];
        self.logout = lo;
        [lo release];
    }
    return self;
}

-(void)control
{
    [self.login isLogin];
    [self.browse isBrowse];
    [self.download isDownload];
    [self.logout isLogout];
}

-(void)dealloc
{
    
    [_login release];
    [_browse release];
    [_download release];
    [_logout release];
    
    [super dealloc];//这里需要写到最后，如果写在release前会先释放父类的，易出问题
    
}
@end

AppDelegate.m

Facade *facade = [[Facade alloc]init];
    [facade control];
    [facade release];

 

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不足：违背了“开闭原则”（通过多态继承达到扩展）。