iPhone 网络连接检测(Wifi,3G,Edge)，功能有点像Reachability [转]

From:http://blog.youkuaiyun.com/favormm/archive/2010/03/06/5352656.aspx

      这个类可以用来检测用户是否连接到internet.  用法非常简单，只有一个方法，返回 YES或NO。

一个简单的例子：

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

  else {  ...  }  

这个类的头文件：

//

//  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

类的实现文件：

//

//  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

 

最后别忘了添加必要的frameworks: SystemConfiguration andlibz.1.1.3.dylib

标题中提到的Reachability也具有检测网络的功能。大家可以参考资料：

http://www.raddonline.com/blogs/geek-journal/iphone-sdk-testing-network-reachability/

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

发表于 @ 2010年03月06日　20:50:00