【代码笔记】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!!!!!!