iOS开发 监听网络状态

当用户第一次打开应用的时候，如果用户还没来得及点击同意连接网络，那么网络请求是失败的，所以，为了让APP的体验更好，我们需要监听网络，如果网络发生变化，需要重新请求数据。当然，用户没联网的状况也可以得到解决！

首先在AppDelegate设置监听网络

• AppDelegate.h

@interface AppDelegate : UIResponder <UIApplicationDelegate>
/*
 当前的网络状态
 */
@property(nonatomic,assign)int netWorkStatesCode;
@end

• AppDelegate.m

- (BOOL)application:(UIApplication *)application willFinishLaunchingWithOptions:(nullable NSDictionary *)launchOptions{
    //网络监控
    [self netWorkChangeEvent];
    return YES;
}

#pragma mark - 检测网络状态变化
-(void)netWorkChangeEvent
{
    [[AFNetworkActivityIndicatorManager sharedManager] setEnabled:YES];
    NSURL *url = [NSURL URLWithString:@"https://www.baidu.com"];
    AFHTTPSessionManager *manager = [[AFHTTPSessionManager alloc] initWithBaseURL:url];
    self.netWorkStatesCode =AFNetworkReachabilityStatusUnknown;
    [manager.reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        self.netWorkStatesCode = status;
        switch (status) {
            case AFNetworkReachabilityStatusReachableViaWWAN:
                NSLog(@"当前使用的是流量模式");
                break;
            case AFNetworkReachabilityStatusReachableViaWiFi:
                NSLog(@"当前使用的是wifi模式");
                break;
            case AFNetworkReachabilityStatusNotReachable:
                NSLog(@"断网了");
                break;
            case AFNetworkReachabilityStatusUnknown:
                NSLog(@"变成了未知网络状态");
                break;
                
            default:
                break;
        }
        [[NSNotificationCenter defaultCenter] postNotificationName:@"netWorkChangeEventNotification" object:@(status)];
    }];
    [manager.reachabilityManager startMonitoring];
}

#pragma mark - 释放应用
-(void)dealloc{
    [[NSNotificationCenter defaultCenter]removeObserver:self name:@"netWorkChangeEventNotification" object:nil];
}

然后在监听页面监听，我的首页写在RecommendViewController中。

• RecommendViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    self.view.backgroundColor=[UIColor whiteColor];
    
    //定制导航栏
    [self CreatNavigationBar];
    
    //无网视图
    [self CreatNoNetView];
    
    //加载瀑布流视图
    [self creatCollectionView];
    
    //先查收看是否有旧的数据，在网络差的时候优先加载旧的数据
    [self loadOldData];
    
    //网络状态发生变化的时候的通知方法
    [[NSNotificationCenter defaultCenter]addObserver:self
                                            selector:@selector(NetWorkStatesChange:) name:@"netWorkChangeEventNotification"
                                              object:nil];
}

/**
 定制导航栏
 */
-(void)CreatNavigationBar{
    UILabel *Titlelabel=[[UILabel alloc] initWithFrame:CGRectMake(0, 0, KScreenW, 44)];
    Titlelabel.font=[UIFont systemFontOfSize:30 weight:3.0];
    Titlelabel.text=@"逗乐视频";
    self.navigationItem.leftBarButtonItem=[[UIBarButtonItem alloc] initWithCustomView:Titlelabel];
    
    self.navigationItem.rightBarButtonItem=[[UIBarButtonItem alloc] initWithImage:[[UIImage imageNamed:@"搜素"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] style:UIBarButtonItemStylePlain target:self action:@selector(clickSearch)];
}

/**
 无网视图
 */
-(void)CreatNoNetView{
    UIView *baseView=[[UIView alloc] initWithFrame:CGRectMake((KScreenW-106)/2, (KScreenH-150-64-49)/2, 106, 150)];
    baseView.backgroundColor=[UIColor clearColor];
    [self.view addSubview:baseView];
    
    //无网占位图
    UIImageView *iconImage=[[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 106, 100)];
    [iconImage setImage:[UIImage imageNamed:@"当前无网络"]];
    [baseView addSubview:iconImage];
    
    //联网按钮
    UIButton *connectBtn=[[UIButton alloc] initWithFrame:CGRectMake(0, 115, 106, 35)];
    [connectBtn setTitle:@"设置网络" forState:UIControlStateNormal];
    [connectBtn setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal];
    [connectBtn setBackgroundColor:YTHColor(253, 177, 76)];
    connectBtn.layer.masksToBounds=YES;
    connectBtn.layer.cornerRadius=5.0f;
    [connectBtn addTarget:self action:@selector(ClickConnectBtn:) forControlEvents:UIControlEventTouchUpInside];
    [baseView addSubview:connectBtn];
}

// 点击进入链接WIFI的设置界面
-(void)ClickConnectBtn:(UIButton *)sender{
    NSString * urlString = @"App-Prefs:root=WIFI";
    if ([[UIApplication sharedApplication] canOpenURL:[NSURL URLWithString:urlString]]) {
        if ([[UIDevice currentDevice].systemVersion doubleValue] >= 10.0) {
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString] options:@{} completionHandler:nil];
        } else {
            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:urlString]];
        }
    }else{
        [SVProgressHUD showInfoWithStatus:@"请手动设置"];
    }
}

最后在处理接收通知的方法里面隐藏或显示相关界面

#pragma mark - 网络状态发生变化通知方法
-(void)NetWorkStatesChange:(NSNotification *)sender{
    int networkState = [[sender object] intValue];
    switch (networkState) {
        case -1:
            //未知网络状态
            
            break;
            
        case 0:
            //没有网络
            [baseView setHidden:NO];
            [self.scrollPageView setHidden:YES];
            break;
            
        case 1:
            //3G或者4G，反正用的是流量
            [baseView setHidden:YES];
            [self.scrollPageView setHidden:NO];
            [self loadData];
            
            break;
            
        case 2:
            //WIFI网络
            [baseView setHidden:YES];
            [self.scrollPageView setHidden:NO];
            [self loadData];
            
            break;
            
        default:
            break;
    }
}

画外音：在我的项目里面，如果一进来的时候是没有网络变化的，也即是说即便没有网络，也不一定会调用这个方法，所以，我在创建视图的时候，先判断当前的网络状况，直接显示或者隐藏相关视图。
e.g:

//获取当前网络，如果为无网，直接隐藏列表视图
   AppDelegate *delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
   if (delegate.netWorkStatesCode == AFNetworkReachabilityStatusNotReachable) {
       [baseView setHidden:NO];
   }else{
      [baseView setHidden:YES];
   }