【代码札记】单例

一，工程图。

二，代码。

NetManager.h

#import <Foundation/Foundation.h>

@interface NetManager : NSObject

+ (id)sharedManager;

-(void)firstPrintf;
-(void)secondPrintf;
-(void)threeprintf;
-(void)fourprintf;



@end

 

NetManager.m

#import "NetManager.h"


static NetManager *manager;

@implementation NetManager

#pragma mark - 获取单例
+ (id)sharedManager{
    if (!manager) {
        manager = [[NetManager alloc]init];
    }
    return manager;
}

-(void)firstPrintf
{
    NSLog(@"first Printf!!!!");
}
-(void)secondPrintf
{
    NSLog(@"second printf!!!!!");
}
-(void)threeprintf
{
    NSLog(@"three printf!!!!!!!");
}
-(void)fourprintf
{
    NSLog(@"fourprintf!!!!!!");
}

 

RootViewController.h

#import <UIKit/UIKit.h>

@interface RootViewController : UIViewController

@end

 

RootViewController.m

#import "RootViewController.h"

//加上单例的头文件
#import "NetManager.h"

@interface RootViewController ()

@end

@implementation RootViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.
    
    
    //单例的用法，单例中的函数，可以在程序中直接使用。
    [[NetManager sharedManager] firstPrintf];
    [[NetManager sharedManager] secondPrintf];
    [[NetManager sharedManager] threeprintf];
    [[NetManager sharedManager] fourprintf];
}

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

 

三，输出。

2015-10-13 13:55:17.551 单例[7675:197760] first Printf!!!!
2015-10-13 13:55:17.551 单例[7675:197760] second printf!!!!!
2015-10-13 13:55:17.551 单例[7675:197760] three printf!!!!!!!
2015-10-13 13:55:17.551 单例[7675:197760] fourprintf!!!!!!