self.view.bounds.size.width返回错误的值

Question

我现在面临一个非常奇怪的问题.获取[[self view] bounds].size.width总是320它不是根据设备改变.iPhone 5,6和6 Plus适用320.000000于所有方法.

- (void)viewDidLoad 
{
    [super viewDidLoad];
    NSLog(@"%f", [[self view] bounds].size.width);
}
- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    NSLog(@"%f", [[self view] bounds].size.width);
}
- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    NSLog(@"%f", [[self view] bounds].size.width);
}

产量

2015-02-11 14:48:03.274 MyApp[2948:86285] 320.000000 
2015-02-11 14:48:03.274 MyApp[2948:86285] 320.000000
2015-02-11 14:48:03.783 MyApp[2948:86285] 320.000000

即使是闪屏也在那里.

如何获得视图的实际大小？

Answer 1

使用

NSLog(@"%f", [[UIScreen mainScreen] bounds].size.width);

代替

NSLog(@"%f", [[self view] bounds].size.width);

它给你预期w/h.

Answer 2

如果您尝试读取[[self view] bounds].size.width值,-(void) viewWillAppear:(BOOL)animated您将看到它将显示正确的值.

In - (void)viewDidLoad [[self view] bounds].size.width将显示您在.xib文件中的确切设计.

请参阅下面的示例和NSLog结果.

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    NSLog(@"%f",[[self view] bounds].size.width);

}
-(void) viewWillAppear:(BOOL)animated{
    NSLog(@"%f",[[self view] bounds].size.width);
    [testIndicator startAnimatingInView:self.view];
}

分别是:

2016-02-17 19:00:47.519 xxxxx[16107:504629] 320.000000
2016-02-17 19:00:47.521 xxxxx[16107:504629] 414.000000

Answer 3

有时，您所需要做的只是在主线程上执行此类操作。

为了我，

DispatchQueue.main.async {
    //access to the frame/bounds
}

然后工作即可直接访问框架/绑定。

Answer 4

viewDidLoad您能否通过简单地创建一个新的测试项目并在的方法中编写以下三个日志语句来进行测试ViewController，如下所示 -

- (void)viewDidLoad {
    NSLog(@"screens = %@", [UIScreen screens]);
    NSLog(@"self.frame= %@", NSStringFromCGRect([[UIScreen mainScreen] bounds]));
    NSLog(@"self.view.frame= %@", NSStringFromCGRect(self.view.frame));
}

构建并运行 - 您将获得设备/屏幕/视图的实际分辨率

样本输出-

2015-02-11 12:45:19.116 Test[1558:87057] screens = (
    "<UIScreen: 0x7ff0b970bcc0; bounds = {{0, 0}, {375, 667}}; mode = <UIScreenMode: 0x7ff0b961b500; size = 750.000000 x 1334.000000>>"
)
2015-02-11 12:45:19.117 Test[1558:87057] self.frame= {{0, 0}, {375, 667}}
2015-02-11 12:45:19.117 Test[1558:87057] self.view.frame= {{0, 0}, {375, 667}}