翻译时费了点时间又不太确定的句子，记录在这里以后看到类似的句式的时候可以参考，或者水平更高了可以更正以前的错误。

in 相关的

Regardless of which content mode is in effect，you can always force your view to redraw its contents by calling setNeedsDisplay or setNeedsDisplayInRect:.

无论内容模式是哪种效果，你都可以调用 setNeedsDisplay 或 setNeedsDisplayInRect: 强制视图重绘它的内容。
In iOS, all coordinate values and distances are specified using floating-point values in units referred to as points.
在 iOS 中，所有的坐标值和距离被指定使用浮点作为单位的值简称为 point。
Inserting a subview in the middle of the list visually places that view behind any views that come later in the list.
插入到列表中间的子视图的视图视觉位置会在所有后面进入列表的视图背后。

to 相关的

In the case of drawing, you specify coordinates relative to the view’s own coordinate system. In the case of geometry changes, you specify coordinates relative to the superview’s coordinate system.

在绘制的情况下，需要指定相对于视图自己的坐标系统的坐标。在形状更改的情况下，需要指定相对于父视图的坐标系统的坐标
Use the window object to convert points and rectangles to or from the window’s local coordinate system.

使用窗口对象将点和矩形转换为窗口的本地坐标系统或从窗口的本地坐标系统转换点和矩形
nimated view transitions are a way for you to make changes to your view hierarchy beyond those offered by view controllers.
以动画过渡视图是让你更改视图层次结构的方式，它在视图层次结构提供的方式之外。
if you want your animation to end on the new value, adding 0.5 to the repeat count causes the animation to complete the extra half cycle needed to end at the new value.

如果你想动画效果在新值结束，添加 0.5 到重复计数使动画效果完成所需的额外一半周期在新值结束。

If this property is set when the window is loaded from its nib file, UIKit automatically installs the view from the associated view controller as the root view of the window.

如果这个属性在窗口从 nib 文件加载后是已设置的，那么 UIKit 自动从已关联的视图控制器安装视图作为窗口的根视图。(主要联系上下文)
Thus, for view transitions, the view controller that was active when you initiated the transition remains active when the transition finishes.
因此，对于视图过渡效果，当你开始过渡效果时视图控制器是活跃，当过渡效果完成时会保留活跃。

The contentMode and contentStretch properties determine how the content is treated when the view’s width or height changes。
contentMode 和 contentStretch

属性决定在视图的宽度或高度变更时应该如何处理内容。

When converting coordinates in rotated views, UIKit converts rectangles under the assumption that you want the returned rectangle to reflect the screen area covered by the source rectangle.
当在一个已旋转的视图中转换坐标时，UIKit 根据“你希望返回的矩形是代表被源矩形覆盖的屏幕区域”的猜测下来转换矩形。
This larger rectangle is actually the smallest rectangle in the bounds of outerView that completely encloses the rotated rectangle.
这个较大的矩形实际上是较小的矩形在外部视图的边界它已完全包围已旋转的矩形。
If a view’s transform property does not contain the identity transform, the frame of that view is undefined and so are the results of its autoresizing behaviors.如果视图的 transform ,
属性不包含恒等转换，那么它的视图的框架是不明确的因此它的自动调整结果也是不明确的。
Listing 3-3 shows an example of the viewDidLoad method from a view controller that creates a custom layer object and adds it to its root view.

清单 3-3 的例子从视图控制器的 viewDidLoad 方法创建一个自定义层对象并添加它到它的根视图中。

The combination of container and content view controllers creates a hierarchy of view controller objects with a single root view controller.
容器和内容视图控制器的组合创建了视图控制器对象与单个根视图控制器的层次结构。

You do not directly modify the views owned by the view controller. Instead, you configure the controls that the navigation controller displays by setting properties on each child view controller.

不要直接修改属于视图控制器的视图。应该通过设置每一个子视图控制器的属性配置导航控制器的控件显示。

For this reason, your view controllers should separate objects needed throughout the lifetime of the view controller from objects that are only necessary some of the time.
因为这个原因，你的视图控制器应该分开在整个视图控制器声明周期都需要的对象和只在某些时候需要的对象。