如何在Swift中旋转UIButton和UILabel的文本? [英] How can you rotate text for UIButton and UILabel in Swift?
问题描述
如何旋转UIButton和UILabel的文本? 90度，180度.
How can you rotate text for UIButton and UILabel? 90 degrees, 180 degrees.
注意:在您将其标记为重复之前，我有意将我的问题建模为该问题的Swift版本:
Note: Before you mark this as a duplicate, I am intentionally modelling my question as a Swift version of this one: How can you rotate text for UIButton and UILabel in Objective-C?
推荐答案
我将答案的格式与此答案.
这是原始标签:
顺时针旋转90度:
yourLabelName.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2)
旋转180度:
yourLabelName.transform = CGAffineTransform(rotationAngle: CGFloat.pi)
逆时针旋转90度:
yourLabelName.transform = CGAffineTransform(rotationAngle: -CGFloat.pi / 2)
执行相同的操作来旋转按钮.幸运的是，触摸事件也旋转了，因此按钮在新的范围内仍然可以单击，而无需执行任何其他操作.
Do the same thing to rotate a button. Thankfully the touch events also get rotated so the button is still clickable in its new bounds without having to do anything extra.
yourButtonName.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2)
注释:
基本格式为CGAffineTransform(rotationAngle: CGFloat)，其中rotationAngle以弧度而不是度为单位.
The basic format is CGAffineTransform(rotationAngle: CGFloat) where rotationAngle is in radians, not degrees.
一个完整的圆(360度)中有2π弧度. Swift包含有用的常量CGFloat.pi.
There are 2π radians in a full circle (360 degrees). Swift includes the useful constant CGFloat.pi.
-
CGFloat.pi=π= 180度 -
CGFloat.pi / 2=π/2 = 90度
CGFloat.pi= π = 180 degreesCGFloat.pi / 2= π/2 = 90 degrees
自动版式:
自动布局不适用于旋转视图. (有关原因的说明，请参见 Frame vs Bounds .)可以通过创建自定义视图来解决此问题. 此答案显示了对于UITextView的操作方法，但这与标签或按钮的基本概念相同. (请注意，由于不需要镜像文本，因此您必须删除该答案中的CGAffineTransformScale行.)
Auto layout does not work with rotated views. (See Frame vs Bounds for an explanation why.) This problem can be solved by creating a custom view. This answer shows how to do it for a UITextView, but it is the same basic concept for a label or button. (Note that you will have to remove the CGAffineTransformScale line in that answer since you don't need to mirror the text.)
相关
- How to do transforms on a CALayer?
- How to apply multiple transforms in Swift
- CTM transforms vs Affine Transforms in iOS (for translate, rotate, scale)
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