iOS —— UIApplication 獲取手機狀態欄中的網絡狀態

通過監聽手機的 statusbar 的狀態還獲取用戶的網絡狀態

能夠區分2G、3G、4G、LTE

注意：使用這種方法時statusbar不可以隱藏，若你的App隱藏了statusbar，則此方法是不可以獲得網絡狀態的。

<pre name="code" class="objc">+ (NSString *)networkingStatesFromStatebar {
    UIApplication *app = [UIApplication sharedApplication];
    NSArray *children = [[[app valueForKeyPath:@"statusBar"] valueForKeyPath:@"foregroundView"] subviews];
    int type = 0;
    for (id child in children) {
        if ([child isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]]) {
            type = [[child valueForKeyPath:@"dataNetworkType"] intValue];
        }
    }
    NSString *stateString = [NSString string];    
    switch (type) {
        case 0:
            stateString = @"notReachable";
            break;
            
        case 1:
            stateString = @"2G";
            break;
            
        case 2:
            stateString = @"3G";
            break;
            
        case 3:
            stateString = @"4G";
            break;
            
        case 4:
            stateString = @"LTE";
            break;
            
        case 5:
            stateString = @"wifi";
            break;
            
        default:
            break;
    }
    return stateString;
}