iOS：Reachability网络监听

iOS利用Reachability确认网络环境3G/WIFI

开发Web等网络应用程序的时候，需要确认网络环境，连接情况等信息。如果没有处理它们，是不会通过Apple的审查的,一般情况下，可以把网络监听放在程序启动时执行。

Apple 的 例程 Reachability 中介绍了取得/检测网络状态的方法。在你的程序中使用 Reachability 只须将该例程中的 Reachability.h 和 Reachability.m 拷贝到你的工程中。如下图：

我们来看看Reachability.h文件中的具体内容：

#import <Foundation/Foundation.h>
#import <SystemConfiguration/SystemConfiguration.h>

//! Project version number for MacOSReachability.
FOUNDATION_EXPORT double ReachabilityVersionNumber;

//! Project version string for MacOSReachability.
FOUNDATION_EXPORT const unsigned char ReachabilityVersionString[];

/**
 * Create NS_ENUM macro if it does not exist on the targeted version of iOS or OS X.
 *
 * @see http://nshipster.com/ns_enum-ns_options/
 **/
#ifndef NS_ENUM
#define NS_ENUM(_type, _name) enum _name : _type _name; enum _name : _type
#endif

extern NSString *const kReachabilityChangedNotification;

//但前网络类型
typedef NS_ENUM(NSInteger, NetworkStatus) {
    // Apple NetworkStatus Compatible Names.
    NotReachable = ,
    ReachableViaWiFi = ,
    ReachableViaWWAN =
};

@class Reachability;

typedef void (^NetworkReachable)(Reachability * reachability);
typedef void (^NetworkUnreachable)(Reachability * reachability);
typedef void (^NetworkReachability)(Reachability * reachability, SCNetworkConnectionFlags flags);

@interface Reachability : NSObject

@property (nonatomic, copy) NetworkReachable    reachableBlock;
@property (nonatomic, copy) NetworkUnreachable  unreachableBlock;
@property (nonatomic, copy) NetworkReachability reachabilityBlock;

@property (nonatomic, assign) BOOL reachableOnWWAN;

//类方法创建网络监听对象
+(instancetype)reachabilityWithHostname:(NSString*)hostname;
// This is identical to the function above, but is here to maintain
//compatibility with Apples original code. (see .m)
+(instancetype)reachabilityWithHostName:(NSString*)hostname;
+(instancetype)reachabilityForInternetConnection;
+(instancetype)reachabilityWithAddress:(void *)hostAddress;
+(instancetype)reachabilityForLocalWiFi;

//实例方法传附件网络监听对象
-(instancetype)initWithReachabilityRef:(SCNetworkReachabilityRef)ref;

-(BOOL)startNotifier;     //开始监听网络
-(void)stopNotifier;      //停止监听网络

-(BOOL)isReachable;        //是否没有网
-(BOOL)isReachableViaWWAN; //是否使自带的网络
-(BOOL)isReachableViaWiFi; //是否是WIFI

// WWAN may be available, but not active until a connection has been established.
// WiFi may require a connection for VPN on Demand.
-(BOOL)isConnectionRequired; // Identical DDG variant.
-(BOOL)connectionRequired; // Apple's routine.
// Dynamic, on demand connection?
-(BOOL)isConnectionOnDemand;
// Is user intervention required?
-(BOOL)isInterventionRequired;

-(NetworkStatus)currentReachabilityStatus;     //获取当前网络状态
-(SCNetworkReachabilityFlags)reachabilityFlags;//
-(NSString*)currentReachabilityString;//当前网络字符串
-(NSString*)currentReachabilityFlags; //当前网络标识

@end

下面我们用代码实现一下对自己主机的网络的监听

方法一：直接使用Reachability这两个文件

//  网络状态监听
//
//  Created by ma c on 16/01/29.
//  Copyright (c) 2016年 XYQ. All rights reserved.
//
#import "AppDelegate.h"
#import "Reachability.h"
@interface AppDelegate ()
@property(nonatomic,strong)Reachability *reachability; //网络监听对象
@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    //创建网络监听
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(networkStateChange) name:kReachabilityChangedNotification object:nil];
    //创建网络监听对象
    self.reachability = [Reachability reachabilityForInternetConnection];
    //self.reachablity = [Reachability reachabilityWithHostName:@"localhost"]; //本机网络
    //开始检测
    [self.reachability startNotifier];

    return YES;
}
//监听网络类型
-(void)NetWorkState
{
    if ([self.reachablity isReachableViaWiFi]) {
        NSLog(@"是WIFI");
    }
    else if([self.reachablity isReachableViaWWAN]){
        NSLog(@"是WWAN");
    }
    else{
        NSLog(@"没有网");
    }
}

//网络链接改变时会调用的方法
-(void)reachabilityChanged:(NSNotification *)note
{
    [self NetWorkState];

    Reachability *currReach = [note object];
    NSParameterAssert([currReach isKindOfClass:[Reachability class]]);

    //对连接改变做出响应处理动作
    NetworkStatus status = [currReach currentReachabilityStatus];
    //如果没有连接到网络就弹出提醒实况
    self.isReachable = YES;
    if(status == NotReachable)
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"网络连接异常" message:@"暂无法访问" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];
        [alert show];
        self.isReachable = NO;
    }
    else
    {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"网络连接信息" message:@"网络连接正常" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];
        [alert show];
        self.isReachable = YES;
    }
}

-(void)dealloc
{
    //停止监听,并移除通知
    [self.reachablity stopNotifier];
    [[NSNotificationCenter defaultCenter]removeObserver:self];
}
@end

输出结果如下：我的电脑连接的就是WIFI

-- ::18.779 网络状态监听[:] 是WIFI

方法二：使用第三方库AFNetworing封装的网络监听方法,创建网络监听管理者进行监听

如何使用AFNetworking做网络监控呢?AFNetworkReachabilityManager这个类中自带着监听网络的方法,同时AFNetworkReachabilityManager还拥有一个枚举,代表着网络状况.

typedef NS_ENUM(NSInteger, AFNetworkReachabilityStatus) {

AFNetworkReachabilityStatusUnknown = -,//未识别的网络

AFNetworkReachabilityStatusNotReachable = ,//不可达的网络(未连接)

AFNetworkReachabilityStatusReachableViaWWAN = ,//2G,3G,4G...

AFNetworkReachabilityStatusReachableViaWiFi = ,//wifi网络

};

下面进行监听：

#import "AppDelegate.h"
#import <AFNetworking/AFNetworkReachabilityManager.h>

@interface AppDelegate ()

@property(nonatomic,strong)AFNetworkReachabilityManager *reachabilityManager;

@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    //创建网络监控对象
    self.reachabilityManager = [AFNetworkReachabilityManager sharedManager];

    //设置监听
    [_reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        switch (status) {
            case AFNetworkReachabilityStatusUnknown:
                NSLog(@"未识别的网络");
                break;

            case AFNetworkReachabilityStatusNotReachable:
                NSLog(@"不可达的网络(未连接)");
                break;

            case AFNetworkReachabilityStatusReachableViaWWAN:
                NSLog(@"2G,3G,4G...的网络");
                break;

            case AFNetworkReachabilityStatusReachableViaWiFi:
                NSLog(@"wifi的网络");
                break;
            default:
                break;
        }
    }];

    //开始监听网络状况.
    [_reachabilityManager startMonitoring];

    return YES;
}

-(void)dealloc{

    //停止监听网络状况.
    [_reachabilityManager stopMonitoring];

}

总结:与Reachability相比之下,AFNetworking是不是代码更加的简练呢?AFNetworking其实封装了Reachability,使我们的代码更加的简单易上手.