iOS 获取蜂窝网络信号强度 包含iPhoneX XS XR XSMASX （最新）

1.虽然各种直接获取信号强度的api都被封杀了。但是还有一个另类的黑魔法可以获取到。那就是遍历UIStatusBar了

网络上有的文章写的会崩溃 比如：

- (int)getSignalStrength{
    if (iPhoneX) {
        id statusBar = [[UIApplication sharedApplication] valueForKeyPath:@"statusBar"];
        id statusBarView = [statusBar valueForKeyPath:@"statusBar"];
        UIView *foregroundView = [statusBarView valueForKeyPath:@"foregroundView"];
        int signalStrength = 0;
        NSArray *subviews = [[foregroundView subviews][2] subviews];
        for (id subview in subviews) {
            if ([subview isKindOfClass:NSClassFromString(@"_UIStatusBarWifiSignalView")]) {
                signalStrength = [[subview valueForKey:@"numberOfActiveBars"] intValue];
                break;
            }else if ([subview isKindOfClass:NSClassFromString(@"_UIStatusBarStringView")]) {
                signalStrength = [[subview valueForKey:@"numberOfActiveBars"] intValue];
                break;
            }
        }
        return signalStrength;
    } }

实测 iPhoneXSMAX 的 _UIStatusBarStringView 里面没有 numberOfActiveBars的值。所以又重新遍历，再xcode中断点看了一下。是需要在

_UIStatusBarPersistentAnimationView  这个图下面去取值就可以了 。。即

- (int)getSignalStrength{
    if (iPhoneX) {
        id statusBar = [[UIApplication sharedApplication] valueForKeyPath:@"statusBar"];
        id statusBarView = [statusBar valueForKeyPath:@"statusBar"];
        UIView *foregroundView = [statusBarView valueForKeyPath:@"foregroundView"];
        int signalStrength = 0;
        NSArray *subviews = [[foregroundView subviews][2] subviews];
        for (id subview in subviews) {
            if ([subview isKindOfClass:NSClassFromString(@"_UIStatusBarWifiSignalView")]) {
                signalStrength = [[subview valueForKey:@"numberOfActiveBars"] intValue];
                break;
            }else if ([subview isKindOfClass:NSClassFromString(@"_UIStatusBarPersistentAnimationView")]) {
                signalStrength = [[subview valueForKey:@"numberOfActiveBars"] intValue];
                break;
            }
        }
        return signalStrength;
    } }