ios - 要检查wifi是否开启但没有互联网连接

Question

我正在使用可达性类来检查代码中的wifi连接。但是有时会出现wifi开启但没有互联网连接或互联网连接不足的问题，这里我的代码循环运行，等待来自所谓的Web服务的任何响应，并且挂断并有时崩溃。
当我在AlertView上单击OK(从Web服务中提取一些数据)时，将执行以下代码
这是我的代码:

        Reachability *ReachObj = [Reachability reachabilityForInternetConnection];
    [ReachObj startNotifier];
    NetworkStatus remoteHostStatus = [ReachObj currentReachabilityStatus];

    if (remoteHostStatus==ReachableViaWiFi) 
    {
        SecondView *ObjSecView=[[SecondView alloc]init];
        [self presentModalViewController:ObjSecView animated:YES];
    }

    else
        if (remoteHostStatus==NotReachable)
    {
        FirstView *objFrstView=[[FeedBackPopOverViewController alloc]init];
        [self presentModalViewController:objFrstView animated:YES];     
    }

我是Objective C的新手。
请先帮助我，谢谢。对于我的语法错误，我们深表歉意。

Answer 1

尝试这个..

SCNetworkReachabilityFlags flags;

 SCNetworkReachabilityRef reachability=SCNetworkReachabilityCreateWithName(NULL, [@"your        web sevice url" UTF8String]);

SCNetworkReachabilityGetFlags(reachability, &flags);
BOOL reachable=!(flags & kSCNetworkReachabilityFlagsConnectionRequired);

CFRelease(reachability);
NSURLRequest *request=[NSURLRequest requestWithURL:[NSURL URLWithString:urlString]];


if([NSURLConnection canHandleRequest:request] && reachable)
 { 
conn=[NSURLConnection connectionWithRequest:request delegate:self];

if(conn)
{
    ////        

}
else
{
    [_delegate performSelector:@selector(httpDataDidFailLoadingWithReason:) 
                    withObject:@"No Internet Connection"    afterDelay:0.1];
 }

 }


 -(void) httpDataDidFailLoadingWithReason:(NSString*)reason
 {

UIAlertView *alertView=[[UIAlertView alloc]initWithTitle:@"abc" 
                                                   message:reason
                                                   delegate:self cancelButtonTitle:@"OK"
                                           otherButtonTitles:nil];
[alertView show];
[alertView release];

  }