IPhone network connection detection (Wifi, 3G, Edge), features a bit like Reachability)

This class can be used to check whether a user is connected to the internet. The usage is very simple. There is only one method, and YES or NO is returned.

A simple example:

if ([Connection isConnected]) {  ...  }     else {  ...  }  

Class header file

//   //  Connection.h     //   #import <Foundation/Foundation.h>   #import <SystemConfiguration/SystemConfiguration.h>   #import <netinet/in.h>   #import <arpa/inet.h>   #import <netdb.h>     @interface Connection : NSObject {   }     + (BOOL) isConnected;     @end 

Class implementation file

//   //  Connection.m  //     #import "Connection.h"     @implementation Connection     + (BOOL) isConnected {       // Create zero addy       struct sockaddr_in zeroAddress;       bzero(&zeroAddress, sizeof(zeroAddress));       zeroAddress.sin_len = sizeof(zeroAddress);       zeroAddress.sin_family = AF_INET;       // Recover reachability flags       SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress);       SCNetworkReachabilityFlags flags;       BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);       CFRelease(defaultRouteReachability);       if (!didRetrieveFlags) {           NSLog(@"Error. Could not recover network reachability flags");           return NO;       }       BOOL isReachable = flags & kSCNetworkFlagsReachable;       BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;       BOOL nonWiFi = flags & kSCNetworkReachabilityFlagsTransientConnection;       NSURL *testURL = [NSURL URLWithString:@"http://www.google.com/"];       NSURLRequest *testRequest = [NSURLRequest requestWithURL:testURL  cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:20.0];       NSURLConnection *testConnection = [[[NSURLConnection alloc] initWithRequest:testRequest delegate:self] autorelease];       return ((isReachable && !needsConnection) || nonWiFi) ? (testConnection ? YES : NO) : NO;   }   @end  

Finally, do not forget to add the necessary frameworks: SystemConfiguration and libz.1.1.3.dylib.

The Reachability mentioned in the title also provides the network detection function. You can reference: http://www.raddonline.com/blogs/geek-journal/iphone-sdk-testing-network-reachability/

Http://developer.apple.com/iphone/library/samplecode/Reachability/index.html