blocks|key|4524422|text|这与您的要求不同，但在Swift+3/+iOS+10中，您可以使用测量类型并进行转换，而无需知道公式！|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4524423|let+result+=+Measurement(value:+45,+unit:+UnitAngle.degrees)
++++.converted(to:+.radians).value|code-block|syntax|javascript|4524424|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This is not identically what you asked, but in Swift 3 / iOS 10, you can use the Measurement type and do the conversion without knowing the formula!

<pre><code>let result = Measurement(value: 45, unit: UnitAngle.degrees)
 .converted(to: .radians).value
</code></pre>

blocks|key|16675|text|苹果提供了这些用于转换的GLKit+functions：|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|16676|func+GLKMathDegreesToRadians(_+degrees:+Float)+->+Float
func+GLKMathRadiansToDegrees(_+radians:+Float)+->+Float|code-block|syntax|javascript|16677|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.apple.com/library/prerelease/ios/documentation/GLkit/Reference/GLKMathUtils/index.html^0|C|F|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@$A|R|B|S|1|T]]|C|$]]|$1|D|3|E|5|F|7|U|8|@]|9|@]|C|$G|H]]|$1|I|3|-4|5|6|7|V|8|@]|9|@]|C|$]]]|J|$K|$5|L|M|N|C|$O|P]]]]

Apple provides these <a href="https://developer.apple.com/library/prerelease/ios/documentation/GLkit/Reference/GLKMathUtils/index.html" rel="noreferrer">GLKit functions</a> for conversion:

<pre><code>func GLKMathDegreesToRadians(_ degrees: Float) -&gt; Float
func GLKMathRadiansToDegrees(_ radians: Float) -&gt; Float
</code></pre>

blocks|key|4524363|text|另外，要将弧度转换为度(如果有人在google上偶然发现了这个)：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4524364|var+degrees+=+radians+*+(180.0+/+M_PI)|code-block|syntax|javascript|4524365|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Also, to convert fron radians to degrees (if anyone stumbles upon this on google):

<pre><code>var degrees = radians * (180.0 / M_PI)
</code></pre>

blocks|key|4524394|text|在创建变量名时，您不再受ASCII字符的限制，因此使用π(π-p)如何：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4524395|typealias+RadianAngle+=+CGFloat

let+π+=+RadianAngle(M_PI)
let+π_x_2+=+RadianAngle(M_PI+*+2)
let+π_2+=+RadianAngle(M_PI_2)
let+π_4+=+RadianAngle(M_PI_4)

extension+RadianAngle+{
++++var+degrees:+CGFloat+{
++++++++return+self+*+180+/+π
++++}
++++init(degrees:+Int)+{
++++++++self+=+CGFloat(degrees)+*+π+/+180
++++}
}|code-block|syntax|javascript|4524396|示例用法：|4524397|let+quarterCircle+=+RadianAngle(degrees:+90)
print("quarter+circle+=+\(quarterCircle)+radians")
//+quarter+circle+=+1.5707963267949+radians

let+halfCircle+=+π
print("half+circle+=+\(halfCircle.degrees)+degrees")
//+half+circle+=+180.0+degrees|4524398|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

You're no longer limited to ASCII characters when creating variable names, so how about this using π (alt-p):

<pre><code>typealias RadianAngle = CGFloat

let π = RadianAngle(M_PI)
let π_x_2 = RadianAngle(M_PI * 2)
let π_2 = RadianAngle(M_PI_2)
let π_4 = RadianAngle(M_PI_4)

extension RadianAngle {
 var degrees: CGFloat {
 return self * 180 / π
 }
 init(degrees: Int) {
 self = CGFloat(degrees) * π / 180
 }
}
</code></pre>

Example usage:

<pre><code>let quarterCircle = RadianAngle(degrees: 90)
print("quarter circle = \(quarterCircle) radians")
// quarter circle = 1.5707963267949 radians

let halfCircle = π
print("half circle = \(halfCircle.degrees) degrees")
// half circle = 180.0 degrees
</code></pre>

blocks|key|4524506|text|我将使用上面提到的相同原则@t1ser，但创建一个CGFloat的扩展，以便更容易地使用小数来表示度数(例如，您可以使用23.4度)：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4524507|extension+CGFloat+{
++++func+degrees()+->+CGFloat+{
++++++++return+self+*+.pi+/+180
++++}

++++init(degrees:+CGFloat)+{
++++++++self+=+degrees.degrees()
++++}
}|code-block|syntax|javascript|4524508|使用它也会很简单(主要是因为我个人不知道如何输入°-如果你也不知道，它是option%2Bshift%2B8+btw)：|4524509|let+degreesToConvert:+CGFloat+=+45.7
.
.
.
let+convertedDegrees+=+degreesToConvert.degrees()|4524510|或者使用初始化器：|4524511|let+convertedDegrees+=+CGFloat(degrees:+45.3)|4524512|entityMap^0|P|7|0|0|10|E|0|0|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|Y|8|@$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|12|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|13|8|@]|D|@]|E|$I|J]]|$1|S|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|T|$]]

I'd use the same principle @t1ser mentioned above, but create an extension of <code>CGFloat</code> to make it easier to use decimals for the degree as well (so you could have a 23.4 degrees, for example): 

<pre><code>extension CGFloat {
 func degrees() -&gt; CGFloat {
 return self * .pi / 180
 }

 init(degrees: CGFloat) {
 self = degrees.degrees()
 }
}
</code></pre>

Using it would be pretty easy as well (mainly because I personally didn't know how to type ° - in case you didn't either, it's <code>option+shift+8</code> btw):

<pre><code>let degreesToConvert: CGFloat = 45.7
.
.
.
let convertedDegrees = degreesToConvert.degrees()
</code></pre>

Or to use the initialiser: 

<pre><code>let convertedDegrees = CGFloat(degrees: 45.3)
</code></pre>

blocks|key|16846|text|在度和弧度之间转换双精度值的最有效、最准确的方法是：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|16847|import+Foundation

extension+Double+{
++++var+radians:+Double+{+return+Measurement(value:+self,+unit:+UnitAngle.degrees).converted(to:+UnitAngle.radians).value+}
++++var+degrees:+Double+{+return+Measurement(value:+self,+unit:+UnitAngle.radians).converted(to:+UnitAngle.degrees).value+}
}|code-block|syntax|javascript|16848|苹果的基金会团队很久以前就解决了这个问题，他们开发了一种超越所有其他解决方案的解决方案：|16849|Measurements+and+Units+-+WWDC+2016,+Session+238|offset|length|16850|entityMap|0|LINK|mutability|MUTABLE|url|https://devstreaming-cdn.apple.com/videos/wwdc/2016/238eemv232k9lp2px30/238/238_hd_measurements_and_units.mp4?dl=1^0|0|0|0|0|1B|0|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|W|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|X|8|@]|9|@$K|Y|L|Z|1|10]]|A|$]]|$1|M|3|-4|5|6|7|11|8|@]|9|@]|A|$]]]|N|$O|$5|P|Q|R|A|$S|T]]]]

The most efficient and accurate way to convert a Double between degrees and radians:
<pre><code>import Foundation

extension Double {
 var radians: Double { return Measurement(value: self, unit: UnitAngle.degrees).converted(to: UnitAngle.radians).value }
 var degrees: Double { return Measurement(value: self, unit: UnitAngle.radians).converted(to: UnitAngle.degrees).value }
}
</code></pre>
The Foundation team at Apple addressed this problem long ago by developing a solution that surpasses all others:
<a href="https://devstreaming-cdn.apple.com/videos/wwdc/2016/238eemv232k9lp2px30/238/238_hd_measurements_and_units.mp4?dl=1" rel="nofollow noreferrer">Measurements and Units - WWDC 2016, Session 238</a>

I am trying to convert this <code>Obj-C</code> code to <code>Swift</code> code but I don't know what the equivalent of this code should be ?

<pre><code>#define DEGREES_TO_RADIANS(degrees)((M_PI * degrees)/180)
</code></pre>

I googled and found <a href="https://stackoverflow.com/questions/24325477/how-to-use-a-objective-c-define-from-swift">this</a>

But I don't understand how to convert that in Swift in my case?

How can I convert from degrees to radians?

Swift

我正在尝试将这段Obj-C代码转换成Swift代码，但是我不知道这段代码的等价物应该是什么？#define DEGREES_TO_RADIANS(degrees)((M_PI * degrees)/180)我在谷歌上找到了但我不明白如何在Swift中将其转换为我的情况？

问如何将度数转换为弧度？
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问如何将度数转换为弧度？EN

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问如何将度数转换为弧度？
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