视图控制器的视图属性

Question

我正在为一个专门的计算器界面上和我有IB以下设置：

我用“容器视图”从IB和将其设置为我的自定义视图控制器，“ButtonViewController”。

然后，我ButtonViewController.m文件中，我有以下几点：

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    self.view.backgroundColor = [UIColor colorWithRed: 0.75 green: 0.0 blue: 0.0 alpha: 1.0 ]; 
    NSLog(@"self.view.bounds.size.width:\t%f", self.view.bounds.size.width); 
    NSLog(@"self.view.bounds.size.height:\t%f", self.view.bounds.size.height); 

    NSLog(@"self.view.frame.size.width:\t%f", self.view.frame.size.width); 
    NSLog(@"self.view.frame.size.height:\t%f", self.view.frame.size.height); 
} 

我得到以下屏幕输出：

而下面的控制台输出：

self.view.bounds.size.width: 320.000000 
self.view.bounds.size.height: 460.000000 
self.view.frame.size.width:  320.000000 
self.view.frame.size.height: 460.000000 

Interface Builder指出t他“容器”宽280px，高364px，所以出于某种原因，我没有得到正确的值。

我甚至试图找到super的bounds和frame尺寸，但它们仍然是320x460。

有人可以告诉我我做错了什么吗？

在此先感谢

[更新]

只是为别人一些信息： 我已经做了一些测试类似的UI控件，并在这里是我的发现： （cvObject是UICollectionView对象）

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 
    // Do any additional setup after loading the view, typically from a nib. 
    NSLog(@"%s: self.cvObject.bounds:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.bounds)); 
    NSLog(@"%s: self.cvObject.frame:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.frame)); 
} 

-(void)viewWillAppear:(BOOL)animated 
{ 
    NSLog(@"%s: self.cvObject.bounds:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.bounds)); 
    NSLog(@"%s: self.cvObject.frame:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.frame)); 
} 

- (void)viewDidAppear:(BOOL)animated 
{ 
    NSLog(@"%s: self.cvObject.bounds:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.bounds)); 
    NSLog(@"%s: self.cvObject.frame:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.frame)); 
} 

-(void)viewWillLayoutSubviews 
{ 
    NSLog(@"%s: self.cvObject.bounds:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.bounds)); 
    NSLog(@"%s: self.cvObject.frame:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.frame)); 
} 

-(void)viewDidLayoutSubviews 
{ 
    NSLog(@"%s: self.cvObject.bounds:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.bounds)); 
    NSLog(@"%s: self.cvObject.frame:\t%@", __FUNCTION__, NSStringFromCGRect(self.cvObject.frame)); 
} 

而我得到的是：

-[FPViewController viewDidLoad]: self.cvObject.bounds: {{0, 0}, {0, 0}} 
-[FPViewController viewDidLoad]: self.cvObject.frame: {{0, 0}, {0, 0}} 
-[FPViewController viewWillAppear:]: self.cvObject.bounds: {{0, 0}, {0, 0}} 
-[FPViewController viewWillAppear:]: self.cvObject.frame: {{0, 0}, {0, 0}} 
-[FPViewController viewWillLayoutSubviews]: self.cvObject.bounds: {{0, 0}, {0, 0}} 
-[FPViewController viewWillLayoutSubviews]: self.cvObject.frame: {{0, 0}, {0, 0}} 
-[FPViewController viewDidLayoutSubviews]: self.cvObject.bounds: {{0, 0}, {280, 312}} 
-[FPViewController viewDidLayoutSubviews]: self.cvObject.frame: {{20, 128}, {280, 312}} 
-[FPViewController viewDidAppear:]: self.cvObject.bounds: {{0, 0}, {280, 312}} 
-[FPViewController viewDidAppear:]: self.cvObject.frame: {{20, 128}, {280, 312}} 

所以你可以看到，它只有在视图设置它的子视图之后，它才能确定对象的框架和边界。

Answer 1

你应该重新审视viewDidAppear这些价值，你会发现，你会看到正确的值有：

- (void)viewDidLoad 
{ 
    [super viewDidLoad]; 

    self.view.backgroundColor = [UIColor colorWithRed: 0.75 green: 0.0 blue: 0.0 alpha: 1.0 ]; 

    // frame and bounds are not entirely reliable at this point 

    NSLog(@"%s: self.view.bounds:\t%@", __FUNCTION__, NSStringFromCGRect(self.view.bounds)); 
    NSLog(@"%s: self.view.frame:\t%@", __FUNCTION__, NSStringFromCGRect(self.view.frame)); 
} 

- (void)viewDidAppear:(BOOL)animated 
{ 
    [super viewDidAppear:animated]; 

    // frame and bounds have generally been updated correctly by this point 

    NSLog(@"%s: self.view.bounds:\t%@", __FUNCTION__, NSStringFromCGRect(self.view.bounds)); 
    NSLog(@"%s: self.view.frame:\t%@", __FUNCTION__, NSStringFromCGRect(self.view.frame)); 
}