为什么self.view.subviews在viewDidLoad中是一个空数组？

Question

我使用Interface Builder创建了一堆UI元素,并使用IBOutlets将它们连接到我的ViewController.

但是,当我尝试self.view.subviews在我的ViewController viewDidLoad方法中迭代时,我发现子视图数组为空.

• ViewController.xib:

  UIView
  |
  - UILabel
  - UIButton
  - // ... more stuff
  - UIToolbar
  

• ViewController.m:

  #import "ViewController.h"
  @interface ViewController ()
  // Interface elements
  @property IBOutlet UILabel *titleLabel;
  @property IBOutlet UIButton *button1;
  // ... etc
  @end
  
  @implementation ViewController
  
  - (void)viewDidLoad {
      [super viewDidLoad];
  
      // BREAK_POINT
  
      // ... code to wire up the UIButtons to dynamically created objects
  }
  

• 调试器输出位于BREAK_POINT:

  (lldb) po self.view
  <UIView: 0x7fa7897e2140; frame = (0 0; 600 600); autoresize = W+H; layer = <CALayer: 0x7fa7897e2210>>
  
  (lldb) po self.view.subviews
  <__NSArrayI 0x7fa789713500>(
  
  )
  (lldb) po [self.view.subviews count];
   nil
  (lldb) po self.button1
  <UIButton: 0x7fa78955ea70; frame = (-23 -15; 46 30); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x7fa7897663d0>>
  

当UIButtons等已经初始化并正确连接到IBOutlets时,为什么self.views.subviews为空的任何想法？

---

编辑1:我将"MainView.xib"重命名为"ViewController.xib"并删除了loadView我的实现,我ViewController.m仍然看到相同的self.view.subviews行为.

Answer 1

尝试这样做

- (void)viewDidLayoutSubviews{


}

加载所有子视图后调用此方法。希望对你有帮助 ：）