iOS開發之監聽網路連接，改變，斷開

iOS開發之監聽網路連接，改變，斷開

做iOS開發時，我們需要監控/監聽網路狀況，蘋果提供了Reachability.h, Reachability.m。

匯入Reachability.h

我們可以在 MainViewController的viewDidLoad方法內部寫上：

[self checkReachability];

之後，具體方法如下

#pragma mark#pragma mark Reachability Methods#pragma mark- (void)checkReachability{    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];    self.reachability = [Reachability reachabilityForInternetConnection];    [self.reachability startNotifier];    [self updateInterfaceWithReachability:self.reachability];}/*! * Called by Reachability whenever status changes. */- (void) reachabilityChanged:(NSNotification *)note{    Reachability* curReach = [note object];    NSParameterAssert([curReach isKindOfClass:[Reachability class]]);    [self updateInterfaceWithReachability:curReach];}- (void)updateInterfaceWithReachability:(Reachability *)reachability{    NetworkStatus status = [reachability currentReachabilityStatus];    AppDelegate *appDelegate = ((AppDelegate *) [[UIApplication sharedApplication] delegate]);    if(status == NotReachable)    {        //No internet        NSLog(@"No Internet");        appDelegate.isNetworkReachable = NO;        [_reachabilityImage setImage:[UIImage imageNamed:@"stop-32.png"]];    }    else if (status == ReachableViaWiFi)    {        //WiFi        NSLog(@"Reachable WIFI");        appDelegate.isNetworkReachable = YES;        [_reachabilityImage setImage:[UIImage imageNamed:@"Airport.png"]];    }    else if (status == ReachableViaWWAN)    {        //3G        NSLog(@"Reachable 3G");        appDelegate.isNetworkReachable = YES;        [_reachabilityImage setImage:[UIImage imageNamed:@"WWAN5.png"]];    }}