檢查互聯網連接iOS 5

Question

我正在製作一個應用程序，需要某些地區的互聯網連接。 我正在尋找檢查互聯網連接並返回警報視圖的最佳方法。 我已經有大約一捅，只能找到做上述的iOS 4的方式，但我做的應用程序是在IOS 5

我有一個看蘋果Reachability示例代碼，但當我嘗試和實現時（這是因爲它爲iOS 4構建的），我的代碼錯誤就像瘋了一樣。

編輯： 當我導入reachability.h文件到項目中，我得到10個錯誤，（其中6我可以簡單地修復）和4我不知道該怎麼做。

Answer 1

我已經改編了Apple的Reachability類，使用ARC，試一試。

/* 

File: Reachability.m 
Abstract: Basic demonstration of how to use the SystemConfiguration Reachablity APIs. 

Version: 2.2 

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constitutes acceptance of these terms. If you do not agree with these terms, 
please do not use, install, modify or redistribute this Apple software. 

In consideration of your agreement to abide by the following terms, and subject 
to these terms, Apple grants you a personal, non-exclusive license, under 
Apple's copyrights in this original Apple software (the "Apple Software"), to 
use, reproduce, modify and redistribute the Apple Software, with or without 
modifications, in source and/or binary forms; provided that if you redistribute 
the Apple Software in its entirety and without modifications, you must retain 
this notice and the following text and disclaimers in all such redistributions 
of the Apple Software. 
Neither the name, trademarks, service marks or logos of Apple Inc. may be used 
to endorse or promote products derived from the Apple Software without specific 
prior written permission from Apple. Except as expressly stated in this notice, 
no other rights or licenses, express or implied, are granted by Apple herein, 
including but not limited to any patent rights that may be infringed by your 
derivative works or by other works in which the Apple Software may be 
incorporated. 

The Apple Software is provided by Apple on an "AS IS" basis. APPLE MAKES NO 
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED 
WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR 
PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN 
COMBINATION WITH YOUR PRODUCTS. 

IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR 
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 
GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR 
DISTRIBUTION OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF 
CONTRACT, TORT (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF 
APPLE HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 

Copyright (C) 2010 Apple Inc. All Rights Reserved. 

*/ 

#import <sys/socket.h> 
#import <netinet/in.h> 
#import <netinet6/in6.h> 
#import <arpa/inet.h> 
#import <ifaddrs.h> 
#import <netdb.h> 

#import <CoreFoundation/CoreFoundation.h> 

#import "Reachability.h" 

#define kShouldPrintReachabilityFlags 0 

static void PrintReachabilityFlags(SCNetworkReachabilityFlags flags, const char* comment) 
{ 
#if kShouldPrintReachabilityFlags 

    NSLog(@"Reachability Flag Status: %c%c %c%c%c%c%c%c%c %s\n", 
      (flags & kSCNetworkReachabilityFlagsIsWWAN)    ? 'W' : '-', 
      (flags & kSCNetworkReachabilityFlagsReachable)   ? 'R' : '-', 

      (flags & kSCNetworkReachabilityFlagsTransientConnection) ? 't' : '-', 
      (flags & kSCNetworkReachabilityFlagsConnectionRequired) ? 'c' : '-', 
      (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) ? 'C' : '-', 
      (flags & kSCNetworkReachabilityFlagsInterventionRequired) ? 'i' : '-', 
      (flags & kSCNetworkReachabilityFlagsConnectionOnDemand) ? 'D' : '-', 
      (flags & kSCNetworkReachabilityFlagsIsLocalAddress)  ? 'l' : '-', 
      (flags & kSCNetworkReachabilityFlagsIsDirect)    ? 'd' : '-', 
      comment 
     ); 
#endif 
} 


@implementation Reachability 
static void ReachabilityCallback(SCNetworkReachabilityRef target, SCNetworkReachabilityFlags flags, void* info) 
{ 
#pragma unused (target, flags) 
    NSCAssert(info != NULL, @"info was NULL in ReachabilityCallback"); 
    NSCAssert([(NSObject*) objc_unretainedObject(info) isKindOfClass: [Reachability class]], @"info was wrong class in ReachabilityCallback"); 

    //We're on the main RunLoop, so an NSAutoreleasePool is not necessary, but is added defensively 
    // in case someon uses the Reachablity object in a different thread. 
    @autoreleasepool {  
     Reachability* noteObject = (Reachability*) objc_unretainedObject(info); 
     // Post a notification to notify the client that the network reachability changed. 
     [[NSNotificationCenter defaultCenter] postNotificationName: kReachabilityChangedNotification object: noteObject]; 
    } 
} 

- (BOOL) startNotifier 
{ 
    BOOL retVal = NO; 
    const void *pointer = objc_unretainedPointer(self); 
    SCNetworkReachabilityContext context = {0, (void *) pointer, NULL, NULL, NULL}; 
    if(SCNetworkReachabilitySetCallback(reachabilityRef, ReachabilityCallback, &context)) 
    { 
     if(SCNetworkReachabilityScheduleWithRunLoop(reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode)) 
     { 
      retVal = YES; 
     } 
    } 
    return retVal; 
} 

- (void) stopNotifier 
{ 
    if(reachabilityRef!= NULL) 
    { 
     SCNetworkReachabilityUnscheduleFromRunLoop(reachabilityRef, CFRunLoopGetCurrent(), kCFRunLoopDefaultMode); 
    } 
} 

- (void) dealloc 
{ 
    [self stopNotifier]; 
    if(reachabilityRef!= NULL) 
    { 
     CFRelease(reachabilityRef); 
    } 
} 

+ (Reachability*) reachabilityWithHostName: (NSString*) hostName; 
{ 
    Reachability* retVal = NULL; 
    SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithName(NULL, [hostName UTF8String]); 
    if(reachability!= NULL) 
    { 
     retVal= [[self alloc] init]; 
     if(retVal!= NULL) 
     { 
      retVal->reachabilityRef = reachability; 
      retVal->localWiFiRef = NO; 
     } 
    } 
    return retVal; 
} 

+ (Reachability*) reachabilityWithAddress: (const struct sockaddr_in*) hostAddress; 
{ 
    SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr*)hostAddress); 
    Reachability* retVal = NULL; 
    if(reachability!= NULL) 
    { 
     retVal= [[self alloc] init]; 
     if(retVal!= NULL) 
     { 
      retVal->reachabilityRef = reachability; 
      retVal->localWiFiRef = NO; 
     } 
    } 
    return retVal; 
} 

+ (Reachability*) reachabilityForInternetConnection; 
{ 
    struct sockaddr_in zeroAddress; 
    bzero(&zeroAddress, sizeof(zeroAddress)); 
    zeroAddress.sin_len = sizeof(zeroAddress); 
    zeroAddress.sin_family = AF_INET; 
    return [self reachabilityWithAddress: &zeroAddress]; 
} 

+ (Reachability*) reachabilityForLocalWiFi; 
{ 
    struct sockaddr_in localWifiAddress; 
    bzero(&localWifiAddress, sizeof(localWifiAddress)); 
    localWifiAddress.sin_len = sizeof(localWifiAddress); 
    localWifiAddress.sin_family = AF_INET; 
    // IN_LINKLOCALNETNUM is defined in <netinet/in.h> as 169.254.0.0 
    localWifiAddress.sin_addr.s_addr = htonl(IN_LINKLOCALNETNUM); 
    Reachability* retVal = [self reachabilityWithAddress: &localWifiAddress]; 
    if(retVal!= NULL) 
    { 
     retVal->localWiFiRef = YES; 
    } 
    return retVal; 
} 

#pragma mark Network Flag Handling 

- (NetworkStatus) localWiFiStatusForFlags: (SCNetworkReachabilityFlags) flags 
{ 
    PrintReachabilityFlags(flags, "localWiFiStatusForFlags"); 

    BOOL retVal = NotReachable; 
    if((flags & kSCNetworkReachabilityFlagsReachable) && (flags & kSCNetworkReachabilityFlagsIsDirect)) 
    { 
     retVal = ReachableViaWiFi; 
    } 
    return retVal; 
} 

- (NetworkStatus) networkStatusForFlags: (SCNetworkReachabilityFlags) flags 
{ 
    PrintReachabilityFlags(flags, "networkStatusForFlags"); 
    if ((flags & kSCNetworkReachabilityFlagsReachable) == 0) 
    { 
     // if target host is not reachable 
     return NotReachable; 
    } 

    BOOL retVal = NotReachable; 

    if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0) 
    { 
     // if target host is reachable and no connection is required 
     // then we'll assume (for now) that your on Wi-Fi 
     retVal = ReachableViaWiFi; 
    } 


    if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand) != 0) || 
     (flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0)) 
    { 
     // ... and the connection is on-demand (or on-traffic) if the 
     //  calling application is using the CFSocketStream or higher APIs 

     if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0) 
     { 
      // ... and no [user] intervention is needed 
      retVal = ReachableViaWiFi; 
     } 
    } 

    if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN) 
    { 
     // ... but WWAN connections are OK if the calling application 
     //  is using the CFNetwork (CFSocketStream?) APIs. 
     retVal = ReachableViaWWAN; 
    } 
    return retVal; 
} 

- (BOOL) connectionRequired; 
{ 
    NSAssert(reachabilityRef != NULL, @"connectionRequired called with NULL reachabilityRef"); 
    SCNetworkReachabilityFlags flags; 
    if (SCNetworkReachabilityGetFlags(reachabilityRef, &flags)) 
    { 
     return (flags & kSCNetworkReachabilityFlagsConnectionRequired); 
    } 
    return NO; 
} 

- (NetworkStatus) currentReachabilityStatus 
{ 
    NSAssert(reachabilityRef != NULL, @"currentNetworkStatus called with NULL reachabilityRef"); 
    NetworkStatus retVal = NotReachable; 
    SCNetworkReachabilityFlags flags; 
    if (SCNetworkReachabilityGetFlags(reachabilityRef, &flags)) 
    { 
     if(localWiFiRef) 
     { 
      retVal = [self localWiFiStatusForFlags: flags]; 
     } 
     else 
     { 
      retVal = [self networkStatusForFlags: flags]; 
     } 
    } 
    return retVal; 
} 
@end 

Answer 2

通過設置-fno-objc-arc編譯器標誌，您可以簡單地從該文件中排除ARC。像這樣：