先下载 Reachability开源库地址：
(一)git hub: https://github.com/tonymillion/Reachability
(二)我自己改动的：http://download.csdn.net/detail/u012460084/8765095
使用：
将Reachability.h和.m文件导入project，在须要使用的地方调用，我是在AppDelegate类中使用的，例如以下：
（.h文件）
#import <UIKit/UIKit.h>
#import "Reachability.h"
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@end
#import "AppDelegate.h"
@interface AppDelegate ()
@end
@implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
Reachability* reach = [Reachability reachabilityWithHostname:@"www.baidu.com"];
NSLog(@"--current status: %@", reach.currentReachabilityString);
//通知监測
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];
//block监測
reach.reachableBlock = ^(Reachability * reachability)
{
NSString * netWorkName = [NSString stringWithFormat:@"Baidu Block Says Reachable:%@", reachability.currentReachabilityString];
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"(%@)网络可用!",netWorkName);
if (reachability.isReachableViaWiFi) {
NSLog(@"(%@)当前通过wifi连接",netWorkName);
} else {
NSLog(@"(%@)wifi未开启。不能用",netWorkName);
}
if (reachability.isReachableViaWWAN) {
NSLog(@"(%@)当前通过2g or 3g or 4g连接",netWorkName);
} else {
NSLog(@"(%@)2g or 3g or 4g网络未使用",netWorkName);
}
});
};
reach.unreachableBlock = ^(Reachability * reachability)
{
NSString * netWorkName = [NSString stringWithFormat:@"GOOGLE Block Says Reachable(%@)", reachability.currentReachabilityString];
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"(%@)网络不可用!",netWorkName);
});
};
[reach startNotifier];
return YES;
}
- (void)reachabilityChanged:(NSNotification*)note {
Reachability * reach = [note object];
if(!reach.isReachable) {
NSLog(@"网络不可用");
}else{
NSLog(@"网络可用");
}
if (reach.isReachableViaWiFi) {
NSLog(@"当前通过wifi连接");
} else {
NSLog(@"wifi未开启，不能用");
}
if (reach.isReachableViaWWAN) {
NSLog(@"当前通过2g or 3g连接");
} else {
NSLog(@"2g or 3g网络未使用");
}
}
- (void)applicationWillResignActive:(UIApplication *)application {
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application {
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application {
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application {
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
- (void)applicationWillTerminate:(UIApplication *)application {
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
@end