曾经的获取状态栏高度可以这样写：

[UIApplication sharedApplication].windows.firstObject.windowScene.statusBarManager.statusBarFrame.size.height;

但是，iOS15更新了之后，就报警告了：

'windows' is deprecated: first deprecated in iOS 15.0 - Use UIWindowScene.windows on a relevant window scene instead

还可以用，就是会报警告。改成下面这样就好啦：

NSSet *set = [[UIApplication sharedApplication] connectedScenes];
UIWindowScene *windowScene = [set anyObject];
UIStatusBarManager *statusBarManager2 =  windowScene.statusBarManager;
NSLog(@"statusBarHeight %f", statusBarManager2.statusBarFrame.size.height);

iPhone12pm测试：

statusBarHeight 47.000000