iOS获取当前网络状态

首先，我们需要拿到状态栏，然后通过runtime去探讨状态栏内部的组成结构

需要#import <objc/message.h>（xcode6下不导入也没影响）

这里为了方便定义枚举

typedef  enum {
    NO_G_WORK = 0,
    TWO_G_WORK,
    THREE_G_WORK,
    FOUR_G_WORK,
    WIFI = 5,
}NET_STATUS;

#pragma mark - getNetworkStatus
- (void)getNetworkStatus
{
    // 状态栏是由当前app控制的，首先获取当前app
    UIApplication *app = [UIApplication sharedApplication];
    
    NSArray *children = [[[app valueForKeyPath:@"statusBar"] valueForKeyPath:@"foregroundView"] subviews];
    
    NET_STATUS type = 0;
    for (id child in children) {
        if ([child isKindOfClass:NSClassFromString(@"UIStatusBarDataNetworkItemView")]) {
            type = [[child valueForKeyPath:@"dataNetworkType"] intValue];
        }
    }

    switch (type) {
        case NO_G_WORK:
            NSLog(@"NO_G_WORK");
            break;
        case TWO_G_WORK:
            NSLog(@"TWO_G_WORK");
            break;
        case THREE_G_WORK:
            NSLog(@"THREE_G_WORK");
            break;
        case FOUR_G_WORK:
            NSLog(@"FOUR_G_WORK");
            break;
        case WIFI:
            NSLog(@"WIFI");
            break;
            
        default:
            break;
    }
    
}

调用上面的方法

- (void)viewWillAppear:(BOOL)animated
{
    [self getNetworkStatus];
}

打印出的type数字对应的网络状态依次是：0 - 无网络; 1 - 2G; 2 - 3G; 3 - 4G; 5 - WIFI