IOS-网络（监听网络状态）

//
//  BWNetWorkTool.h
//  IOS_0131_检测网络状态
//
//  Created by ma c on 16/1/31.
//  Copyright © 2016年 博文科技. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface BWNetWorkTool : NSObject
///是否是WiFi
+ (BOOL)isEnableWiFi;
///是否是3G
+ (BOOL)isEnable3G;

@end

//
//  BWNetWorkTool.m
//  IOS_0131_检测网络状态
//
//  Created by ma c on 16/1/31.
//  Copyright © 2016年 博文科技. All rights reserved.
//

#import "BWNetWorkTool.h"
#import "Reachability.h"

@implementation BWNetWorkTool

//是否是WiFi
+ (BOOL)isEnableWiFi
{
    return [[Reachability reachabilityForLocalWiFi] currentReachabilityStatus] !=NotReachable;
}
//是否是3G
+ (BOOL)isEnable3G
{
    return [[Reachability reachabilityForInternetConnection] currentReachabilityStatus] !=NotReachable;
}


@end

//
//  ViewController.m
//  IOS_0131_检测网络状态
//
//  Created by ma c on 16/1/31.
//  Copyright © 2016年 博文科技. All rights reserved.
//

#import "ViewController.h"
#import "Reachability.h"
#import "BWNetWorkTool.h"

@interface ViewController ()

@property (nonatomic, strong) Reachability *reachability;

@end

@implementation ViewController
/*
 检测网络状态
 1.在网络应用中，需要对用户设备的网络状态进行实时监控，目的：
   a.让用户了解自己的网络状态，防止一些误会（怪应用无能）
   b.根据用户的网络状态进行智能处理，节省用户流量，提高用户体验
     WIFI/3G/4G网络：自动下载高清图片
            低速网络：只能下载缩略图
            没有网络：智能显示离线的缓存数据
   c.苹果官方提供了一个叫Reachability的示例程序，便于开发者检测网络状态
     https://developer.apple.com/library/ios/samplecode/Reachability/Reachability.zip
 
 2.Reachability的使用步骤
 1>添加框架SystemConfiguration.framework
 2>添加源代码
 3>包含头文件 - #import "Reachability.h"
 
 3.常见用法
 1>是否是WiFi
 + (BOOL)isEnableWiFi
 {
 return [[Reachability reachabilityForLocalWiFi] currentReachabilityStatus] !=NotReachable;
 }
 2>是否是3G
 + (BOOL)isEnable3G
 {
 return [[Reachability reachabilityForInternetConnection] currentReachabilityStatus] !=NotReachable;
 }
 */

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //监听网络状态发生改变通知
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(networkStateChange) name:kReachabilityChangedNotification object:nil];
    
    //获得Reachability对象
    self.reachability = [Reachability reachabilityForInternetConnection];
    
    //开始监控
    [self.reachability startNotifier];
    
//    //获取Reachability对象
//    Reachability *wifi = [Reachability reachabilityForLocalWiFi];
//    //获取Reachability对象的当前网络状态
//    NetworkStatus wifiStatus = wifi.currentReachabilityStatus;
//    
//    if (wifiStatus !=NotReachable) {
//        NSLog(@"wifi");
//    }
    
}

- (void)networkStateChange
{
    NSLog(@"网络状态改变了");
    [self changeNetworkState];
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    [self changeNetworkState];
}

- (void)changeNetworkState
{
    if ([BWNetWorkTool isEnableWiFi]) {
        NSLog(@"WiFi环境");
    }else if ([BWNetWorkTool isEnable3G]){
        NSLog(@"手机自带网络");
    }else{
        NSLog(@"没有网络");
    }
}

- (void)dealloc
{
    [self.reachability stopNotifier];
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

@end