#import <UIKit/UIKit.h>#import "Reachability.h"@interface AppDelegate : UIResponder <UIApplicationDelegate>{   Reachability *reachability;   BOOL WarningViaWWAN;}@property (strong, nonatomic) UIWindow *window;- (void)ReachabilitySniff:(Reachability*) curReach;- (void)ReachabilitySniffNotification:(NSNotification* )notification;- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex;@end 

#import "AppDelegate.h"#import "RootViewController.h"@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{  self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];  // Override point for customization after application launch.    RootViewController *rootVC=[[RootViewController alloc]init];  UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:rootVC];  self.window.rootViewController=nav;      //啟動網絡嗅探功能  WarningViaWWAN = TRUE;    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(ReachabilitySniffNotification:) name:kReachabilityChangedNotification object:nil];    if (!reachability) {    reachability = [Reachability reachabilityForInternetConnection];  }  [reachability startNotifier];    [self performSelector:@selector(ReachabilitySniff:) withObject:reachability afterDelay:20];        self.window.backgroundColor = [UIColor whiteColor];  [self.window makeKeyAndVisible];  return YES;}#pragma mark -網絡嗅探- (void)ReachabilitySniffNotification:(NSNotification* )notification{  Reachability* curReach = [notification object];  [self performSelector:@selector(ReachabilitySniff:) withObject:curReach afterDelay:2];}- (void)ReachabilitySniff:(Reachability*) curReach{  NSLog(@"ReachabilitySniffNewWorkStatus");  if (!curReach) {    return;  }  NetworkStatus status = [curReach currentReachabilityStatus];  switch (status) {    case ReachableViaWiFi:    {      UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"您正在使用WiFi網絡" message:Nil delegate:self cancelButtonTitle:Nil otherButtonTitles:@"本次不再提醒",@"知道了", nil];      [alert show];      break;    }    case ReachableViaWWAN:    {       UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"您正在使用移動網絡，運營商會收取流量費，建議使用WiFi網絡" message:Nil delegate:self cancelButtonTitle:Nil otherButtonTitles:@"本次不再提醒",@"知道了", nil];        [alert show];       break;    }    case NotReachable:    {      UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"沒有網絡" message:Nil delegate:self cancelButtonTitle:Nil otherButtonTitles:@"本次不再提醒",@"知道了", nil];      [alert show];      break;    }  }}