iPhoneX,也就是刘海屏的情况下 foregroundView报错

报错原因：

[<UIStatusBar_Modern 0x12f8084b0> valueForUndefinedKey:]: this class is not key value coding-compliant for the key foregroundView.

解决方法：

  NSArray *subviews = nil;
    // 不能用 [[self deviceVersion] isEqualToString:@"iPhone X"] 来判断，因为模拟器不会返回 iPhone X
    id statusBar = [[UIApplication sharedApplication] valueForKeyPath:@"statusBar"];
    if ([statusBar isKindOfClass:NSClassFromString(@"UIStatusBar_Modern")]) {
        subviews = [[[statusBar valueForKey:@"statusBar"] valueForKey:@"foregroundView"] subviews];
    } else {
        subviews = [[statusBar valueForKey:@"foregroundView"] subviews];
    }