#import <Foundation/Foundation.h>

 #import "AFNetworkReachabilityManager.h"

 #import "Singleton.h" //此处是将一个普通类转化为单例类的头文件

 @interface GGNetworkJudge : NSObject

 singleton_interface(GGNetworkJudge);

 //监测网络状态

 - (void)checkNetworkStatus;

 @end

 #import "GGNetworkJudge.h"

 #import <UIKit/UIKit.h>

 @implementation GGNetworkJudge

 singleton_implementation(GGNetworkJudge);

 #pragma mark - 私有方法

 #pragma mark 网络状态变化提示

 -(void)alert:(NSString *)message{

     UIAlertView *alertView=[[UIAlertView alloc]initWithTitle:@"系统信息" message:message delegate:nil cancelButtonTitle:@"确定" otherButtonTitles: nil];

     [alertView show];

 }

 #pragma mark 网络状态监测

 -(void)checkNetworkStatus{

     AFNetworkReachabilityManager *manager = [AFNetworkReachabilityManager sharedManager];

     //开始监控

     [manager startMonitoring];

     // 检测网络连接的单例,网络变化时的回调方法

     [manager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {

         switch (status) {

             case AFNetworkReachabilityStatusReachableViaWWAN:

                 //[self alert:@"2G/3G/4G Connection."];

                 [self alert:@"网络已连接"];

                 break;

             case AFNetworkReachabilityStatusReachableViaWiFi:

                 // [self alert:@"WiFi Connection."];

                 [self alert:@"网络已连接"];

                 break;

             case AFNetworkReachabilityStatusNotReachable:

                 //  [self alert:@"Network not found."];

                 [self alert:@"网络已断开，请检查网络设置"];

                 break;

             default:

                 // [self alert:@"Unknown."];

                 [self alert:@"网络未知错误"];

                 break;

         }

     }];

 }

 @end

 /*

 专门用来保存单例代码

  最后一行不要加 \

 */

 // @interface

 #define singleton_interface(className) \

 + (className *)shared##className;

 // @implementation

 #define singleton_implementation(className) \

 static className *_instance; \

 + (id)allocWithZone:(NSZone *)zone \

 { \

     static dispatch_once_t onceToken; \

     dispatch_once(&onceToken, ^{ \

         _instance = [super allocWithZone:zone]; \

     }); \

     return _instance; \

 } \

 + (className *)shared##className \

 { \

     static dispatch_once_t onceToken; \

     dispatch_once(&onceToken, ^{ \

         _instance = [[self alloc] init]; \

     }); \

     return _instance; \

 }