【读书笔记】UIWindow-WindowLevel

UIKIT_EXTERN const UIWindowLevel UIWindowLevelNormal;
UIKIT_EXTERN const UIWindowLevel UIWindowLevelAlert;
UIKIT_EXTERN const UIWindowLevel UIWindowLevelStatusBar;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.        NSLog(@"UIWindowLevelNormal=%f UIWindowLeveStatusBar=%f UIWindowLevelAlert=%f",UIWindowLevelNormal,UIWindowLevelStatusBar,UIWindowLevelAlert);         return YES;}

2015-07-19 21:02:45.448 WindowLevelDemo[775:24283] UIWindowLevelNormal=0.000000 UIWindowLeveStatusBar=1000.000000 UIWindowLevelAlert=2000.000000