如何接收连接类型已更改的通知（3G、Edge、Wifi、GPRS）

Posted 2023-02-23

【中文标题】如何接收连接类型已更改的通知（3G、Edge、Wifi、GPRS）

【英文标题】：How do I receive notifications that the connection has changed type (3G, Edge, Wifi, GPRS)

【发布时间】：2011-10-07 09:10:34

【问题描述】：

有没有办法发现当前连接是 3G、Edge 还是 WiFi，并收到通知？或者只是一种发现连接是否为 WiFi 的方法？

【参考方案1】：

你应该使用 Apple 的 Reachability 类

http://developer.apple.com/library/ios/#samplecode/Reachability/Listings/Classes_Reachability_h.html

实施后，您可以在委托中使用它：

- (void) configureTextField:  (Reachability*) curReach

    NetworkStatus netStatus = [curReach currentReachabilityStatus];
    BOOL connectionRequired= [curReach connectionRequired];
    NSString* statusString= @"non";
    switch (netStatus)
    
        case NotReachable:
        
            statusString = @"Access Not Available";

            //Minor interface detail- connectionRequired may return yes, even when the host is unreachable.  We cover that up here...
            connectionRequired= NO;  
            break;
        

        case ReachableViaWWAN:
        
            statusString = @"Reachable WWAN";


            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Cellular Data Detected" message:@"You are using Cellular data such as 3G or Edge. Downloading large amount of data may effect your cellular internet package costs. To avoid such extra cost kindly use Wifi." 
                                                           delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [alert show];
            [alert release];


            break;
        
        case ReachableViaWiFi:
        
            statusString= @"Reachable WiFi";

            break;
        
    
    if(connectionRequired)
    
        statusString= [NSString stringWithFormat: @"%@, Connection Required", statusString];
    
    NSLog(@"Network= %@",statusString);
    if ([statusString isEqualToString:@"Access Not Available"])
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"No Internet Connection" message:@"It seems you are not connected to the internet, the app will try to load from the last cached data - assuming this data exist." 
                                                       delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [alert show];
        [alert release];
    
    //textField.text= statusString;



- (void) updateInterfaceWithReachability: (Reachability*) curReach

    if(curReach == hostReach)
    
        //[self configureTextField: remoteHostStatusField imageView: remoteHostIcon reachability: curReach];
       // NetworkStatus netStatus = [curReach currentReachabilityStatus];
       // BOOL connectionRequired= [curReach connectionRequired];

        [self configureTextField:curReach];

       

【参考方案2】：

是的，Apple 有一个示例项目可以证明这一点。 Reachability

还有here's 一个例子。