学步园

　　通过Reachability来判断设备的网络环境，方法比较简单。直接将Reachability.h和Reachability.m加入到工程中，然后添加SystemConfiguration.framework框架，就可以使用了。工程截图：

ViewController.h

//
//  ViewController.h
//  NetworkStatusDemo
//
//  Created by Fox on 12-3-15.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>
#import "Reachability.h"

@interface ViewController : UIViewController{
    IBOutlet UILabel *netstatus;

    Reachability* status; //网络状态

}
@property (retain, nonatomic) IBOutlet UILabel *netstatus;
@property (retain, nonatomic) Reachability* status;

+ (BOOL) IsEnableWIFI;
+ (BOOL) IsEnable3G;

@end

 

ViewController.m

//
//  ViewController.m
//  NetworkStatusDemo
//
//  Created by Fox on 12-3-15.
//  Copyright (c) 2012年 __MyCompanyName__. All rights reserved.
//

#import "ViewController.h"
#import "Reachability.h"

@implementation ViewController
@synthesize netstatus;
@synthesize status;



- (void)viewDidLoad
{
    [super viewDidLoad];

    self.status = [[Reachability alloc] init];
    status = [Reachability reachabilityWithHostName:@"www.cnblogs.com/foxmin"];
switch ([status currentReachabilityStatus]) {
case NotReachable:
// 没有网络连接
            self.netstatus.text = @"没有网络连接";
break;
case ReachableViaWWAN:
// 使用3G网络
            self.netstatus.text = @"使用3G网络";
break;
case ReachableViaWiFi:
// 使用WiFi网络
            self.netstatus.text = @"使用WiFi网络";
break;
    }

//程序启动时，检查程序的网络环境
    if ([ViewController IsEnableWIFI] && ![ViewController IsEnable3G]) {
        self.netstatus.text = @"使用WiFi网络";
    }else if(![ViewController IsEnableWIFI] && [ViewController IsEnable3G]){
        self.netstatus.text = @"使用3G网络";
    }else  self.netstatus.text = @"没有网络连接";

}

- (void)viewDidUnload
{
    [self setNetstatus:nil];
    [super viewDidUnload];
// Release any retained subviews of the main view.
// e.g. self.myOutlet = nil;
}

- (void)dealloc {
    [netstatus release];
    [super dealloc];
}


/*
 *判断是否通过wifi
*/
+ (BOOL) IsEnableWIFI {
return ([[Reachability reachabilityForLocalWiFi] currentReachabilityStatus] != NotReachable);
}

/*
 *判断是否通过3G
*/
+ (BOOL) IsEnable3G {
return ([[Reachability reachabilityForInternetConnection] currentReachabilityStatus] != NotReachable);
}


@end