苹果工程师建议不要完全依赖Rechability。
来自SO帖子(引用的来源)
On a WWDC talk this year the Apple engineer on stage recommended users to never base
the application internet access on the Reachability example app status. Often
reachability doesn't provide a complete information (it is based on a complex mechanism)
and the suggestion provided by the engineer was this:
1. try to do your internet connection, whatever it is the Reachability status;
then set your UI hint based on success/fail result
2. if it fails due to networking issue, then register to Reachability and retry again
when Reachability gives the green light; this is needed when you want to recover
automatically from the fail condition
3. in any case give the user the possibility to "force a retry", whatever is the
Reachability status. If it succeeds, reset your UI hint immediately.
我能做什么?
每次我需要建立连接时,例如
NSData* data = [NSData dataWithContentsOfURL:[NSURL URLWithString:[NSString
stringWithFormat:@"http://myadress.com"]]];
[self performSelectorOnMainThread:@selector(responseHandler:)
withObject:data waitUntilDone:TRUE];
- (void)responseHandler:(NSData *)responseData {
if(!responseData) {
ReachabilityController *reachability = [[ReachabilityController alloc] init];
[reachability checkReachability];
return;
}
}
那里正在发生的事情是,只有在连接失败时才会测试可达性。我创建了一个通用的ReachabilityController,只处理可达性。我这样做是为了每次发出请求时,可以从所有其他控制器中进行调用。
我的ReachabilityController.m看起来像:
-(void) checkReachability {
Reachability* internetAvailable = [Reachability reachabilityForInternetConnection];
NetworkStatus netStatus = [internetAvailable currentReachabilityStatus];
NSString *messageText;
if (netStatus == NotReachable)
{
messageText = [NSString stringWithFormat:@"Internet access not available"];
}
else
{
Reachability *netReach = [Reachability reachabilityWithHostName:host];
NetworkStatus hostStatus = [netReach currentReachabilityStatus];
if (hostStatus == NotReachable)
{
messageText = [NSString stringWithFormat:@"Host Unreachable"];
}
else
{
messageText = [NSString stringWithFormat:@"Problem with remote service"];
}
}
NSLog(@"%@", messageText);
}
它不会导致您的应用程序崩溃,因为您正在自己处理“nil”数据参数,并最终确定原因。
希望这可以帮助您!
更新:
如果您显示有关Internet连接的错误消息,则Apple可能会拒绝您的应用程序。他们非常重视与iPhone的声誉。如果互联网连接可用,但是您的应用程序报告互联网连接不可用,则这将被认为是非常严重的。