Why can not I get UIStatusBarSignalStrengthItemView?

In order to obtain the wifi or cellular signal strength on iphone, I wrote the following code as reference for various sites, but it does not come in IF statement of "UIStatusBarSignalStrengthItemView" or "_UIStatusBarCellularSignalView".

Do you need permission?

■Development environment

Xcode9.4.1

iPhoneX　iOS:11.0.1

■Test1.m

#import "Test1.h"
@implementation Test1 : NSObject 

- (int)antennaBar
{

    NSLog(@"%@",[[[UIApplication sharedApplication]     valueForKeyPath:@"statusBar"] subviews]);

    NSLog(@"antennaBar 1");
    NSLog(@"antennaBar 2");
//    NSArray *subviews = [[[apps valueForKey:@"statusBar"]     valueForKey:@"foregroundView"] subviews];
    NSArray *subviews = nil;
    NSLog(@"antennaBar 3");
    id statusBar = [[UIApplication sharedApplication] valueForKey:@"statusBar"];
    NSLog(@"antennaBar 4");
    if ([statusBar isKindOfClass:NSClassFromString(@"UIStatusBar_Modern")]) {
        NSLog(@"antennaBar 5");
    subviews = [[[statusBar valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];
} else {
    NSLog(@"antennaBar 6");
    subviews = [[statusBar valueForKey:@"foregroundView"] subviews];
}
NSLog(@"antennaBar 7");
NSString *dataNetworkItemView = nil;

NSLog(@"antennaBar 8");
for (id subview in subviews) {

    NSLog(@"Class - %@", NSStringFromClass([subview class]));

    NSLog(@"antennaBar aaaaaaa");
    if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarSignalStrengthItemView") class]]) {
        NSLog(@"antennaBar bbbbbb");
        dataNetworkItemView = subview;
        break;
    }
    if([subview isKindOfClass:[NSClassFromString(@"_UIStatusBarCellularSignalView") class]]) {
        NSLog(@"antennaBar eeeeee");
        dataNetworkItemView = subview;

        int fffff = [subview valueForKey:@"numberOfActiveBars"];
        NSLog(@"fffff=%d",fffff);
        break;
    }
}

for (id subview in subviews)
{
    NSLog(@"antennaBar cccccc");
    if([subview isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]])
    {
        NSLog(@"antennaBar dddddd");
        [(NSNumber*)[subview valueForKey:@"dataNetworkType"] intValue];
    }
}

NSLog(@"antennaBar 9");


NSLog(@"12345");
id statusBaraaaa = [[UIApplication sharedApplication] valueForKey:@"statusBar"];
NSArray *children = nil;
NSLog(@"23456");
children = [[[statusBaraaaa valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];
NSLog(@"34567");
int type = 0;
NSLog(@"45678");
for (id child in children) {
    NSLog(@"56789");
    if ([child isKindOfClass:[NSClassFromString(@"UIStatusBarDataNetworkItemView") class]]) {
        NSLog(@"67890");
        type = [[child valueForKeyPath:@"dataNetworkType"] intValue];
    }
}

if (type == 0) {
    return NO;
}else{
    return YES;
}

int aaa = [[dataNetworkItemView valueForKey:@"signalStrengthBars"] intValue];


NSLog(@"aaa=%d",aaa);

return aaa;
}

@end

■Test1.h

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

@interface Test1 : NSObject
- (int)antennaBar;
@end

■Log OutPut

( "<_UIStatusBar: 0x14e809020: regions={\n bottomLeading = \"<_UIStatusBarRegion: 0x1d013bd00: identifier=bottomLeading, enabled=1, displayItems={(\n)}>\";\n expandedLeading = \"<_UIStatusBarRegion: 0x1d013bbc0: identifier=expandedLeading, enabled=0, displayItems={(\n)}>\";\n expandedTrailing = \"<_UIStatusBarRegion: 0x1d013bc60: identifier=expandedTrailing, enabled=0, displayItems={(\n)}>\";\n leading = \"<_UIStatusBarRegion: 0x1d013b940: identifier=leading, enabled=1, displayItems={(\n <_UIStatusBarDisplayItem: 0x1d019b450: identifier=_UIStatusBarTimeItem.shortTimeDisplayIdentifier, item=<_UIStatusBarTimeItem: 0x1d046c700: identifier=_UIStatusBarTimeItem>, view=<_UIStatusBarStringView: 0x14e825ae0; frame = (14.3333 3.66667; 38.3333 18); text = '12:10'; userInteractionEnabled = NO; layer = <_UILabelLayer: 0x1d0281f40>>>\n)}>\";\n pill = \"<_UIStatusBarRegion: 0x1d013b8a0: identifier=pill, enabled=0, displayItems={(\n)}>\";\n systemUpdates = \"<_UIStatusBarRegion: 0x1d0

Class - UIView

aaaaaaa

Class - UIView

aaaaaaa

Class - UIView

aaaaaaa

Class - UIView

aaaaaaa

Class - UIView

aaaaaaa

Class - UIView

aaaaaaa

cccccc

12345

23456

34567

45678

56789

Solution

While getting the signal strength by inspecting the status bar view hierarchy worked in some previous versions of iOS, that no longer works as of iOS 11. Also, relying on internal views is (and has always been) ground for rejection in the app store review process.

There is no supported way to get the cellular signal strength. Source: comment on Apple Developer Forum. The only supported way to get the WiFi signal strength is using the NEHotspotNetwork signalStrength property. But this property is only available to hotspot helper apps, and requires a special entitlement.