Question

我正在尝试在我的应用中显示一个简单的设置屏幕，而我正在使用Autolayout。由于我的应用程序支持横向，并且当手机处于横向状态时设置控件不完全适合垂直，我添加了UIScrollview。

似乎UIScrollview和Autolayout的组合在这里和其他地方都是一个常见的问题。我已经阅读了一些关于它的文章，从它可以看出，似乎一个好的方法去做我想要做的是将我的各种控件放在一个视图中，就像一个带有约束的“contentView”在该视图中对齐。然后让contentView成为UIScrollView的唯一子视图。我有contentView约束绑定到UIScrollView的边缘。

UINavigationView -> UIScrollview -> contentView (UIView) -> Control Subviews

xib

它在肖像中工作正常，即使我在contentView中添加需要滚动查看的内容，但是当我去横向时，它不会让我向下滚动得足够远。这就像我旋转时内容大小重置为可见区域（或导航控制器superview的框架）的框架。

simulator

我想知道我是否需要检查旋转，然后再次设置内容大小？如果是这样，有没有办法从视图（contentView）动态获取该大小？

感谢您提供的任何帮助！吉姆

Answer 1

有两个组件可以让自动布局正确处理滚动视图：

滚动视图子视图的约束：滚动视图的contentSize将由滚动视图的子视图的约束决定。因此，您需要对滚动视图（即第二个切换）中的最后一个控件的底部约束为其超级视图（即滚动视图）。看起来你确实有这个。滚动视图的子视图的这些约束将根据需要自动调整滚动视图的contentSize。

顺便说一下，这个第二个开关的底部约束的constant通常默认为一些较大的值，对应于它在纵向中的布局方式。您可能希望为最后一个控件选择并编辑此底部约束并更改它以使其成为“标准”值。

滚动视图本身的约束：您需要确保滚动视图本身与其超级视图具有底部约束（并确保不具有高度滚动视图上的约束）。这将在屏幕旋转时调整滚动视图的frame。我想知道你的项目中是否会遗漏这个。

您可以通过在调试器中运行您的应用来确认这一点，点击“暂停”按钮：

enter image description here

然后在(lldb)提示符下输入po [[UIWindow keyWindow] recursiveDescription]，您会看到以下内容：

(lldb) po [[UIWindow keyWindow] recursiveDescription]
<UIWindow: 0x8b97ff0; frame = (0 0; 320 480); autoresize = W+H; gestureRecognizers = <NSArray: 0x8b98450>; layer = <UIWindowLayer: 0x8b97af0>>
   | <UIView: 0x8b9a830; frame = (0 0; 320 480); transform = [0, -1, 1, 0, 0, 0]; autoresize = RM+BM; layer = <CALayer: 0x8b9a240>>
   |    | <UIScrollView: 0x8b9aa50; frame = (0 0; 480 320); clipsToBounds = YES; autoresize = RM+TM; gestureRecognizers = <NSArray: 0x8b9a6c0>; layer = <CALayer: 0x8b9a130>; contentOffset: {0, 0}>
   |    |    | <UILabel: 0x8b9ade0; frame = (20 20; 63 21); text = 'Settings'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x8b9aec0>>
   |    |    | <UILabel: 0x8b9d590; frame = (20 49; 51 21); text = 'View 1'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x8b9d6b0>>
   |    |    | <UILabel: 0x8b9db70; frame = (408 49; 51 21); text = 'View 2'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x8b9dc10>>
   |    |    | <UIView: 0x8b9de60; frame = (335 78; 124 53); autoresize = RM+BM; layer = <CALayer: 0x8b9dec0>>
   |    |    | <UIView: 0x8b9e000; frame = (20 78; 284 53); autoresize = RM+BM; layer = <CALayer: 0x8b9e060>>
   |    |    | <UILabel: 0x8b9e250; frame = (20 139; 59 21); text = 'Slider 1'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x8b9e2f0>>
   |    |    | <UISlider: 0x8b9e460; frame = (18 238; 444 34); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x8b9e5c0>; value: 0.500000>
   |    |    |    | <UIView: 0x8ace410; frame = (2 16; 440 2); userInteractionEnabled = NO; layer = <CALayer: 0x8ace470>>
   |    |    |    |    | <UIView: 0x8ace610; frame = (221 0; 219 2); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8ace670>>
   |    |    |    |    |    | <UIView: 0x8ace6e0; frame = (-221 0; 440 2); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8ace740>>
   |    |    |    |    |    |    | <CAGradientLayer: 0x8ace7b0> (layer)
   |    |    |    |    | <UIView: 0x8ace7e0; frame = (0 0; 221 2); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8ace840>>
   |    |    |    | <UIImageView: 0x8ace9d0; frame = (207 1; 31 31); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8acea60>>
   |    |    |    |    | <UIImageView: 0x8ace8b0; frame = (-13 -6.5; 57 43.5); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8ace940>>
   |    |    | <UISlider: 0x8b9e850; frame = (17 168; 444 34); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x8b9e930>; value: 0.500000>
   |    |    |    | <UIView: 0x8ba5430; frame = (2 16; 440 2); userInteractionEnabled = NO; layer = <CALayer: 0x8ba5490>>
   |    |    |    |    | <UIView: 0x8acc190; frame = (221 0; 219 2); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8acae30>>
   |    |    |    |    |    | <UIView: 0x8acc3f0; frame = (-221 0; 440 2); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8ac84d0>>
   |    |    |    |    |    |    | <CAGradientLayer: 0x8accb90> (layer)
   |    |    |    |    | <UIView: 0x8acdf50; frame = (0 0; 221 2); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8acdfb0>>
   |    |    |    | <UIImageView: 0x8ace070; frame = (207 1; 31 31); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8ace100>>
   |    |    |    |    | <UIImageView: 0x8acdfe0; frame = (-13 -6.5; 57 43.5); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8acdc80>>
   |    |    | <UILabel: 0x8b9e9c0; frame = (20 209; 59 21); text = 'Slider 2'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x8b9ea60>>
   |    |    | <UISwitch: 0x8b9ece0; frame = (411 279; 51 31); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x8b9edd0>>
   |    |    |    | <_UISwitchInternalViewNeueStyle1: 0x8b9f0c0; frame = (0 0; 51 31); gestureRecognizers = <NSArray: 0x8b723f0>; layer = <CALayer: 0x8b9f1c0>>
   |    |    |    |    | <UIView: 0x8b9f750; frame = (35.5 0; 15.5 31); clipsToBounds = YES; layer = <CALayer: 0x8b9f7b0>>
   |    |    |    |    |    | <UIView: 0x8b9f3b0; frame = (-35.5 0; 51 31); layer = <CALayer: 0x8b9f410>>
   |    |    |    |    | <UIView: 0x8b9f6c0; frame = (0 0; 35.5 31); clipsToBounds = YES; layer = <CALayer: 0x8b9f720>>
   |    |    |    |    |    | <UIView: 0x8b9f440; frame = (0 0; 51 31); layer = <CALayer: 0x8b9f4a0>>
   |    |    |    |    | <UIView: 0x8ba11e0; frame = (0 0; 51 31); layer = <CALayer: 0x8ba1240>>
   |    |    |    |    |    | <UIImageView: 0x8ba0f10; frame = (39 16; 0 0); alpha = 0; userInteractionEnabled = NO; layer = <CALayer: 0x8ba10f0>>
   |    |    |    |    |    | <UIImageView: 0x8ba1120; frame = (12 16; 0 0); userInteractionEnabled = NO; layer = <CALayer: 0x8ba11b0>>
   |    |    |    |    | <UIImageView: 0x8b9fab0; frame = (7 -6; 57 43.5); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8ba0a40>>
   |    |    | <UISwitch: 0x8b974b0; frame = (411 318; 51 31); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x8b75570>>
   |    |    |    | <_UISwitchInternalViewNeueStyle1: 0x8b7d6a0; frame = (0 0; 51 31); gestureRecognizers = <NSArray: 0x8b845e0>; layer = <CALayer: 0x8b78750>>
   |    |    |    |    | <UIView: 0x8b7df70; frame = (35.5 0; 15.5 31); clipsToBounds = YES; layer = <CALayer: 0x8b7be00>>
   |    |    |    |    |    | <UIView: 0x8b72410; frame = (-35.5 0; 51 31); layer = <CALayer: 0x8b7a660>>
   |    |    |    |    | <UIView: 0x8b7ba80; frame = (0 0; 35.5 31); clipsToBounds = YES; layer = <CALayer: 0x8b7bd00>>
   |    |    |    |    |    | <UIView: 0x8b78dd0; frame = (0 0; 51 31); layer = <CALayer: 0x8b7ba20>>
   |    |    |    |    | <UIView: 0x8b81580; frame = (0 0; 51 31); layer = <CALayer: 0x8b77ee0>>
   |    |    |    |    |    | <UIImageView: 0x8b97880; frame = (39 16; 0 0); alpha = 0; userInteractionEnabled = NO; layer = <CALayer: 0x8b7e1a0>>
   |    |    |    |    |    | <UIImageView: 0x8b77460; frame = (12 16; 0 0); userInteractionEnabled = NO; layer = <CALayer: 0x8b7e350>>
   |    |    |    |    | <UIImageView: 0x8b80670; frame = (7 -6; 57 43.5); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x8b80700>>
   |    |    | <UILabel: 0x8b97cf0; frame = (335 284; 67 21); text = 'Switch 1'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x8b808b0>>
   |    |    | <UILabel: 0x8b79d60; frame = (335 323; 67 21); text = 'Switch 2'; clipsToBounds = YES; opaque = NO; autoresize = RM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x8b77b90>>
   |    |    | <UIImageView: 0x8ac44f0; frame = (476 473; 3 7); alpha = 0; opaque = NO; autoresize = LM; userInteractionEnabled = NO; layer = <CALayer: 0x8a89130>>
   |    |    | <UIImageView: 0x8ac2be0; frame = (313 316; 7 3); alpha = 0; opaque = NO; autoresize = TM; userInteractionEnabled = NO; layer = <CALayer: 0x8ac2c70>>
   |    | <_UILayoutGuide: 0x8b9cb20; frame = (0 0; 0 20); hidden = YES; layer = <CALayer: 0x8b9e5f0>>
   |    | <_UILayoutGuide: 0x8ac4440; frame = (0 320; 0 0); hidden = YES; layer = <CALayer: 0x8a90370>>

检查frame的{{1}}（例如，上面是针对iPhone上的横向），并确保它与屏幕尺寸相对应。如果您尚未定义滚动视图与其超级视图之间的约束，则此UIScrollView可能不正确。

Answer 2

也许其他人会为此提供更好的解决方案，但是最快但不会对当前版本进行太多改动就是完全按照你所说的做法：检查轮换然后再次设置内容大小 。它将在您的设置视图控制器实现文件中完成：

- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
    self.scrollView.contentSize = self.contentView.bounds.size;
}

...假设您已将相同的文件插件分别添加到UIScrollView和UIView scrollView和contentView。{/ p>

UIScrollview与景观中的Autolayout内容大小

2 个答案: