iOS 检测网络是否可以使用

#define kAppleUrlTocheckWifi @"http://captive.apple.com"
//检测网络是否可以使用
+(BOOL)isReach{

// 1.将网址初始化成一个OC字符串对象
NSString *newUrlStr = kAppleUrlTocheckWifi;

// 2.构建网络URL对象, NSURL
NSURL *url = [NSURL URLWithString:newUrlStr];
// 3.创建网络请求
NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:3];
// 创建同步链接
NSURLResponse *response = nil;
NSError *error = nil;
NSData *data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

NSString* result1 = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];

if ([result1 containsString:@"Success"])
{
NSLog(@"可以上网了");
//   [PronetwayGeneralHandle shareHandle].NetworkCanUse = YES;
return YES;
}else {
NSLog(@"未联网");
//[self showNetworkStatus:@"未联网"];
//   [PronetwayGeneralHandle shareHandle].NetworkCanUse = NO;
return NO;
}

}