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
|
- (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
|
- (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";
}
}
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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/
