ios - 为什么applicationFrame高度为460时窗口480的高度？

Question

我在AppDelegate类中创建了一个TabBar VC，通过[[UIScreen mainScreen] bounds]设置了窗口框架。由于我已显示状态栏，因此高度应为460，但看起来应为480。如果我手动将高度设置为460，则会在选项卡底部减少触摸识别。下面是代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
UIColor *brownNavBarColor = [[UIColor alloc] initWithRed:0.78f green:0.56f blue:0.06f alpha:1.0f];
[application setStatusBarHidden:NO];

CGRect windowRect = [[UIScreen mainScreen] bounds];
self.window = [[UIWindow alloc] initWithFrame:windowRect];

CGRect appFrame = [[UIScreen mainScreen] applicationFrame];

NSLog(@" appFrame %f", appFrame.origin.y);
NSLog(@" appFrame %f", appFrame.size.height);

NSLog(@" window.frame %f", self.window.frame.origin.y);
NSLog(@" window.frame %f", self.window.frame.size.height);

NSLog(@" window.bounds %f", self.window.bounds.origin.y);
NSLog(@" window.bounds %f", self.window.bounds.size.height);

[self.window makeKeyAndVisible];

self.ingredientTabVC2 = [[NewIngredientViewController alloc] initWithNibName:nil bundle:NULL];
self.ingredientNC2 = [[UINavigationController alloc] initWithRootViewController:self.ingredientTabVC2];
[self.ingredientNC2.navigationBar setTintColor:brownNavBarColor];

self.ingredientTabVC3 = [[IngredientTabViewController alloc] initWithNibName:nil bundle:NULL];
self.ingredientNC3 = [[UINavigationController alloc] initWithRootViewController:self.ingredientTabVC3];
[self.ingredientNC3.navigationBar setTintColor:brownNavBarColor];

self.tabBarController = [[UITabBarController alloc] initWithNibName:nil bundle:NULL];
self.tabBarController.viewControllers = [[NSArray alloc] initWithObjects: self.ingredientNC2, self.ingredientNC3, nil];


[self.window setRootViewController:self.tabBarController];
return YES;
}

这给出了日志输出

2013-02-12 23:04:21.867 SingleTest[24221:c07]  appFrame 20.000000
2013-02-12 23:04:21.868 SingleTest[24221:c07]  appFrame 460.000000
2013-02-12 23:04:21.869 SingleTest[24221:c07]  window.frame 0.000000
2013-02-12 23:04:21.870 SingleTest[24221:c07]  window.frame 480.000000
2013-02-12 23:04:21.870 SingleTest[24221:c07]  window.bounds 0.000000
2013-02-12 23:04:21.871 SingleTest[24221:c07]  window.bounds 480.000000

有人可以解释这种差异背后的原因吗？

Answer 1

从UIScreen的文档中:

applicationFrame:

此属性包含屏幕边界减去状态栏所占据的区域(如果可见)。建议使用此属性来检索应用程序的初始窗口大小。矩形以点为单位指定。

范围:

包含屏幕的边界矩形，以点为单位。 (只读)
bounds包括状态栏，而applicationFrame不包括。

还要注意applicationFrame的y起源是20。

您希望主窗口充满屏幕。设置窗口的rootViewController时，它将自动调整为applicationFrame。