blocks|key|4572280|text|为什么不创建一个同时包含struct和@objc+class的文件，如下所示：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4572281|import+UIKit

extension+UIColor+{
++++convenience+init(hex:+Int)+{
++++++++let+components+=+(
++++++++++++R:+CGFloat((hex+>>+16)+&+0xff)+/+255,
++++++++++++G:+CGFloat((hex+>>+08)+&+0xff)+/+255,
++++++++++++B:+CGFloat((hex+>>+00)+&+0xff)+/+255
++++++++)
++++++++self.init(red:+components.R,+green:+components.G,+blue:+components.B,+alpha:+1)
++++}
}

extension+CGColor+{
++++class+func+colorWithHex(hex:+Int)+->+CGColorRef+{
++++++++return+UIColor(hex:+hex).CGColor
++++}
}

struct+Constant+{
++++static+let+kParseApplicationId+=+"5678"
++++static+let+kParseClientKey+=+"1234"
++++static+var+kAppGreenColor:+UIColor+{+return+UIColor(hex:0x67B632)+}
++++static+var+kTextBlackColor:+UIColor+{+return+UIColor(hex:0x000000)+}
++++static+var+kSomeBgBlueColor:+UIColor+{+return+UIColor(hex:0x0000FF)+}
++++static+var+kLineGrayCGColor:+CGColor+{+return+CGColor.colorWithHex(0xCCCCCC)+}
++++static+var+kLineRedCGColor:+CGColor+{+return+CGColor.colorWithHex(0xFF0000)+}
}


@objc+class+Constants:+NSObject+{
++++private+override+init()+{}

++++class+func+parseApplicationId()+->+String+{+return+Constant.kParseApplicationId+}
++++class+func+parseClientKey()+->+String+{+return+Constant.kParseClientKey+}
++++class+func+appGreenColor()+->+UIColor+{+return+Constant.kAppGreenColor+}
++++class+func+textBlackColor()+->+UIColor+{+return+Constant.kTextBlackColor+}
++++class+func+someBgBlueColor()+->+UIColor+{+return+Constant.kSomeBgBlueColor+}
++++class+func+lineGrayCGColor()+->+CGColor+{+return+Constant.kLineGrayCGColor+}
++++class+func+lineRedCGColor()+->+CGColor+{+return+Constant.kLineRedCGColor+}
}|code-block|syntax|javascript|4572282|要在Objective-C文件中使用，请在需要使用常量时添加以下内容：|4572283|#import+"ProjectModuleName-Swift.h"|4572284|Swift用法：|4572285|self.view.backgroundColor+=+Constant.kAppGreenColor|4572286|Objective-C的用法：|4572287|self.view.backgroundColor+=+[Constants+appGreenColor];|4572288|这样你就可以在一个地方更新整个应用程序的颜色、默认文本和web服务urls。|4572289|entityMap^0|C|6|J|B|0|0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|10|8|@$9|11|A|12|B|C]|$9|13|A|14|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|15|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|16|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|17|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|18|8|@]|D|@]|E|$]]|$1|Q|3|R|5|H|7|19|8|@]|D|@]|E|$I|J]]|$1|S|3|T|5|6|7|1A|8|@]|D|@]|E|$]]|$1|U|3|V|5|H|7|1B|8|@]|D|@]|E|$I|J]]|$1|W|3|X|5|6|7|1C|8|@]|D|@]|E|$]]|$1|Y|3|-4|5|6|7|1D|8|@]|D|@]|E|$]]]|Z|$]]

Why not create a file with both a <code>struct</code> and an <code>@objc class</code>, something like this: 

<pre><code>import UIKit

extension UIColor {
 convenience init(hex: Int) {
 let components = (
 R: CGFloat((hex &gt;&gt; 16) &amp; 0xff) / 255,
 G: CGFloat((hex &gt;&gt; 08) &amp; 0xff) / 255,
 B: CGFloat((hex &gt;&gt; 00) &amp; 0xff) / 255
 )
 self.init(red: components.R, green: components.G, blue: components.B, alpha: 1)
 }
}

extension CGColor {
 class func colorWithHex(hex: Int) -&gt; CGColorRef {
 return UIColor(hex: hex).CGColor
 }
}

struct Constant {
 static let kParseApplicationId = "5678"
 static let kParseClientKey = "1234"
 static var kAppGreenColor: UIColor { return UIColor(hex:0x67B632) }
 static var kTextBlackColor: UIColor { return UIColor(hex:0x000000) }
 static var kSomeBgBlueColor: UIColor { return UIColor(hex:0x0000FF) }
 static var kLineGrayCGColor: CGColor { return CGColor.colorWithHex(0xCCCCCC) }
 static var kLineRedCGColor: CGColor { return CGColor.colorWithHex(0xFF0000) }
}


@objc class Constants: NSObject {
 private override init() {}

 class func parseApplicationId() -&gt; String { return Constant.kParseApplicationId }
 class func parseClientKey() -&gt; String { return Constant.kParseClientKey }
 class func appGreenColor() -&gt; UIColor { return Constant.kAppGreenColor }
 class func textBlackColor() -&gt; UIColor { return Constant.kTextBlackColor }
 class func someBgBlueColor() -&gt; UIColor { return Constant.kSomeBgBlueColor }
 class func lineGrayCGColor() -&gt; CGColor { return Constant.kLineGrayCGColor }
 class func lineRedCGColor() -&gt; CGColor { return Constant.kLineRedCGColor }
}
</code></pre>

For use in Objective-C files add this when you need to use constants: 

<pre><code>#import "ProjectModuleName-Swift.h"
</code></pre>

Swift usage:

<pre><code>self.view.backgroundColor = Constant.kAppGreenColor
</code></pre>

Objective-C usage:

<pre><code>self.view.backgroundColor = [Constants appGreenColor];
</code></pre>

This way you can update colors, default text, web service urls for whole app in one place.

blocks|key|4572320|text|如果您想让代码中的其他Swift类型仅通过class访问这些常量，则应将let语句设为私有：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4572321|private+let+AppGreenColor+=+UIColor(red:+0.2,+green:+0.7,+blue:+0.3+alpha:+1.0)

@objc+class+Constant+{
++++class+func+appGreenColor()+->+UIColor+{+return+AppGreenColor+}
}|code-block|syntax|javascript|4572322|在Swift中，您可以这样使用它们：|4572323|UIColor+*greenColor+=+Constant.appGreenColor|4572324|由于let语句是私有的，下面这行代码现在将不再编译：|4572325|UIColor+*greenColor+=+appGreenColor|4572326|entityMap^0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|R|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|U|8|@]|9|@]|A|$]]|$1|M|3|N|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

You should make the let statements private if you want to make other Swift types in your code to access these constants only via class:

<pre><code>private let AppGreenColor = UIColor(red: 0.2, green: 0.7, blue: 0.3 alpha: 1.0)

@objc class Constant {
 class func appGreenColor() -&gt; UIColor { return AppGreenColor }
}
</code></pre>

In Swift, you can use them like this:

<pre><code>UIColor *greenColor = Constant.appGreenColor
</code></pre>

The following line will not compile anymore now since the let statement is private:

<pre><code>UIColor *greenColor = appGreenColor
</code></pre>

blocks|key|65965|text|虽然这可能会延迟或多余，但我可以使用以下代码使其工作：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|65966|@objcMembers+class+Flags:+NSObject+{
++++static+let+abcEnabled+=+false
++++static+let+pqrEnabled+=+false
++++.
++++.
++++.
}|code-block|syntax|javascript|65967|显然，要在objc+c代码中使用，必须执行#import+"ProjectModuleName-Swift.h“|65968|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

Though this might be late or redundant, I could make it work with the following code :

<pre><code>@objcMembers class Flags: NSObject {
 static let abcEnabled = false
 static let pqrEnabled = false
 .
 .
 .
}
</code></pre>

Obviously, to use in objc c code, you have to do #import "ProjectModuleName-Swift.h"

Simply I have a struct that stores the application constants as below:

<pre><code>struct Constant {

 static let ParseApplicationId = "xxx"
 static let ParseClientKey = "xxx"

 static var AppGreenColor: UIColor {
 return UIColor(hexString: "67B632")
 }
}
</code></pre>

These constants can be use in Swift code by calling <code>Constant.ParseClientKey</code> for example. But in my code, it also contains some Objective-C classes. So my question is how to use these constants in the Objective-C code? 

If this way to declare constants is not good then what is the best way to create global constants to be used in both Swift and Objective-C code?

How to use Swift struct in Objective-C

Objective-C

Swift

简单地说，我有一个存储应用程序常量的结构，如下所示：struct Constant {    static let ParseApplicationId = "xxx"    static let ParseClientKey = "xxx"    static var AppGreenColor: UIColor {...

问如何在Objective-C中使用Swift结构
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