旋转时更改子视图框架

Question

我在基本视图控制器的 uiview 中添加 subView(backgroundView)，它在 potratate 中运行良好，但是当我将方向从 potraite 更改为横向时，它的帧大小与 potrait 相同，我想在旋转时更改子视图的大小。

UIView *activityView = [[UIView alloc] initWithFrame:self.view.bounds];
CGRect frame = activityView.frame;
activityView.frame = frame;
activityView.backgroundColor = [UIColor clearColor];
activityView.alpha = 0.0f;
[self.view addSubview:activityView];
self.activityView = activityView;
UIView *backgroundView = [[UIView alloc]initWithFrame:activityView.bounds];
backgroundView.alpha = 0.0f;
[backgroundView setBackgroundColor:[UIColor lightGrayColor]];
[self.activityView backgroundView];
UIActivityIndicatorView *spinning = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleGray];
[self.activityView spinning];
spinning.center = activityView.center;
self.activityView.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin;
[spinning setColor:[UIColor lightGrayColor]];
[spinning startAnimating];

Answer 1

为此，您必须向视图添加约束（自动布局）。

例如：

[self.view addConstraint:[NSLayoutConstraint constraintWithItem:containerView
                                                      attribute:NSLayoutAttributeTop
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self.view
                                                      attribute:NSLayoutAttributeTop
                                                     multiplier:1.0
                                                       constant:0.0]];

[self.view addConstraint:[NSLayoutConstraint constraintWithItem:containerView
                                                      attribute:NSLayoutAttributeLeading
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self.view
                                                      attribute:NSLayoutAttributeLeading
                                                     multiplier:1.0
                                                       constant:0.0]];

[self.view addConstraint:[NSLayoutConstraint constraintWithItem:containerView
                                                      attribute:NSLayoutAttributeBottom
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self.view
                                                      attribute:NSLayoutAttributeBottom
                                                     multiplier:1.0
                                                       constant:0.0]];

[self.view addConstraint:[NSLayoutConstraint constraintWithItem:containerView
                                                      attribute:NSLayoutAttributeTrailing
                                                      relatedBy:NSLayoutRelationEqual
                                                         toItem:self.view
                                                      attribute:NSLayoutAttributeTrailing
                                                     multiplier:1.0
                                                       constant:0.0]];

编辑：

不要忘记在视图上将translatesAutoresizingMaskIntoConstraints 属性设置为NO。

（将self.view 和containerView 替换为您的观点）。