如果你想在iOS程序中提供一仅在wifi网络下使用(Reeder)，或者在没有网络状态下提供离线模式(Evernote)。那么你会使用到Reachability来实现网络检测。
写本文的目的
了解Reachability都能做什么
检测3中网络环境
2G/3G
wifi
无网络
如何使用通知
单个controller
多个controller
简单的功能:
仅在wifi下使用
Reachability简介
Reachablity 是一个iOS下检测,iOS设备网络环境用的库。
监视目标网络是否可用
监视当前网络的连接方式
监测连接方式的变更
安装
创建 network 工程（network是我创建的demo工程，附件中可以下载到）
使用Cocoaspod安装依赖
在项目中添加 SystemConfiguration.framework 库
由于Reachability非常常用。直接将其加入到Supporting Files/networ-Prefix.pch中:
#import <Reachability/Reachability.h>
#import <Reachability/Reachability.h>
如果你还不知道cocoaspod是什么,看这里:
http://witcheryne.iteye.com/blog/1873221
使用
stackoverflow上有一篇回答，很好的解释了reachability的用法
http://stackoverflow.com/questions/11177066/how-to-use-ios-reachability
一般情况一个Reachability实例就ok了。
一个Controller只需要一个Reachability
Block方式使用
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- (void)viewDidLoad { [super viewDidLoad]; DLog(@"开启 www.apple.com 的网络检测"); Reachability* reach = [Reachability reachabilityWithHostname:@"www.apple.com"]; DLog(@"-- current status: %@", reach.currentReachabilityString); // start the notifier which will cause the reachability object to retain itself! [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil]; reach.reachableBlock = ^(Reachability * reachability) { dispatch_async(dispatch_get_main_queue(), ^{ self.blockLabel.text = @"网络可用"; self.blockLabel.backgroundColor = [UIColor greenColor]; }); }; reach.unreachableBlock = ^(Reachability * reachability) { dispatch_async(dispatch_get_main_queue(), ^{ self.blockLabel.text = @"网络不可用"; self.blockLabel.backgroundColor = [UIColor redColor]; }); }; [reach startNotifier]; } - (void)viewDidLoad { [super viewDidLoad]; DLog(@"开启 www.apple.com 的网络检测"); Reachability* reach = [Reachability reachabilityWithHostname:@"www.apple.com"]; DLog(@"-- current status: %@", reach.currentReachabilityString); // start the notifier which will cause the reachability object to retain itself! [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil]; reach.reachableBlock = ^(Reachability * reachability) { dispatch_async(dispatch_get_main_queue(), ^{ self.blockLabel.text = @"网络可用"; self.blockLabel.backgroundColor = [UIColor greenColor]; }); }; reach.unreachableBlock = ^(Reachability * reachability) { dispatch_async(dispatch_get_main_queue(), ^{ self.blockLabel.text = @"网络不可用"; self.blockLabel.backgroundColor = [UIColor redColor]; }); }; [reach startNotifier]; } |
使用notification的方式
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- (void)viewDidLoad { [super viewDidLoad]; DLog(@"开启 www.apple.com 的网络检测"); Reachability* reach = [Reachability reachabilityWithHostname:@"www.apple.com"]; DLog(@"-- current status: %@", reach.currentReachabilityString); // start the notifier which will cause the reachability object to retain itself! [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil]; [reach startNotifier]; } - (void) reachabilityChanged: (NSNotification*)note { Reachability * reach = [note object]; if(![reach isReachable]) { self.notificationLabel.text = @"网络不可用"; self.notificationLabel.backgroundColor = [UIColor redColor]; self.wifiOnlyLabel.backgroundColor = [UIColor redColor]; self.wwanOnlyLabel.backgroundColor = [UIColor redColor]; return; } self.notificationLabel.text = @"网络可用"; self.notificationLabel.backgroundColor = [UIColor greenColor]; if (reach.isReachableViaWiFi) { self.wifiOnlyLabel.backgroundColor = [UIColor greenColor]; self.wifiOnlyLabel.text = @"当前通过wifi连接"; } else { self.wifiOnlyLabel.backgroundColor = [UIColor redColor]; self.wifiOnlyLabel.text = @"wifi未开启，不能用"; } if (reach.isReachableViaWWAN) { self.wwanOnlyLabel.backgroundColor = [UIColor greenColor]; self.wwanOnlyLabel.text = @"当前通过2g or 3g连接"; } else { self.wwanOnlyLabel.backgroundColor = [UIColor redColor]; self.wwanOnlyLabel.text = @"2g or 3g网络未使用"; } } - (void)viewDidLoad { [super viewDidLoad]; DLog(@"开启 www.apple.com 的网络检测"); Reachability* reach = [Reachability reachabilityWithHostname:@"www.apple.com"]; DLog(@"-- current status: %@", reach.currentReachabilityString); // start the notifier which will cause the reachability object to retain itself! [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil]; [reach startNotifier]; } - (void) reachabilityChanged: (NSNotification*)note { Reachability * reach = [note object]; if(![reach isReachable]) { self.notificationLabel.text = @"网络不可用"; self.notificationLabel.backgroundColor = [UIColor redColor]; self.wifiOnlyLabel.backgroundColor = [UIColor redColor]; self.wwanOnlyLabel.backgroundColor = [UIColor redColor]; return; } self.notificationLabel.text = @"网络可用"; self.notificationLabel.backgroundColor = [UIColor greenColor]; if (reach.isReachableViaWiFi) { self.wifiOnlyLabel.backgroundColor = [UIColor greenColor]; self.wifiOnlyLabel.text = @"当前通过wifi连接"; } else { self.wifiOnlyLabel.backgroundColor = [UIColor redColor]; self.wifiOnlyLabel.text = @"wifi未开启，不能用"; } if (reach.isReachableViaWWAN) { self.wwanOnlyLabel.backgroundColor = [UIColor greenColor]; self.wwanOnlyLabel.text = @"当前通过2g or 3g连接"; } else { self.wwanOnlyLabel.backgroundColor = [UIColor redColor]; self.wwanOnlyLabel.text = @"2g or 3g网络未使用"; } } |
附件demo说明
开启wifi状态
关闭wifi的状态
遗留问题
如何在多个controller之前共用一个Reachability(附件demo中是一个controller一个Reachability实例)
应该在什么使用停止Reachability的检测.
最新内容请见作者的GitHub页：http://qaseven.github.io/