blocks|key|6388|text|您将需要一个函数来生成0到1范围内的随机CGFloat：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|6389|extension+CGFloat+{
++++static+func+random()+->+CGFloat+{
++++++++return+CGFloat(arc4random())+/+CGFloat(UInt32.max)
++++}
}|code-block|syntax|javascript|6390|然后，您可以使用此命令创建随机颜色：|6391|extension+UIColor+{
++++static+func+random()+->+UIColor+{
++++++++return+UIColor(
+++++++++++red:+++.random(),
+++++++++++green:+.random(),
+++++++++++blue:++.random(),
+++++++++++alpha:+1.0
++++++++)
++++}
}|6392|如果你想要一个随机的alpha，也可以为它创建另一个随机数。|6393|现在可以像这样指定视图的背景色：|6394|self.view.backgroundColor+=+.random()|6395|entityMap^0|K|7|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|W|8|@$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|Z|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|10|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|11|8|@]|D|@]|E|$I|J]]|$1|O|3|P|5|6|7|12|8|@]|D|@]|E|$]]|$1|Q|3|R|5|6|7|13|8|@]|D|@]|E|$]]|$1|S|3|T|5|H|7|14|8|@]|D|@]|E|$I|J]]|$1|U|3|-4|5|6|7|15|8|@]|D|@]|E|$]]]|V|$]]

<p>You're going to need a function to produce random <code>CGFloat</code>s in the range 0 to 1:</p>

<pre><code>extension CGFloat {
    static func random() -&gt; CGFloat {
        return CGFloat(arc4random()) / CGFloat(UInt32.max)
    }
}
</code></pre>

<p>Then you can use this to create a random colour:</p>

<pre><code>extension UIColor {
    static func random() -&gt; UIColor {
        return UIColor(
           red:   .random(),
           green: .random(),
           blue:  .random(),
           alpha: 1.0
        )
    }
}
</code></pre>

<p>If you wanted a random alpha, just create another random number for that too.</p>

<p>You can now assign your view's background colour like so:</p>

<pre><code>self.view.backgroundColor = .random()
</code></pre>


blocks|key|4513901|text|创建一个函数来生成随机颜色：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4513902|func+getRandomColor()+->+UIColor+{
+++++//Generate+between+0+to+1
+++++let+red:CGFloat+=+CGFloat(drand48())+++
+++++let+green:CGFloat+=+CGFloat(drand48())+
+++++let+blue:CGFloat+=+CGFloat(drand48())++

+++++return+UIColor(red:red,+green:+green,+blue:+blue,+alpha:+1.0)
}|code-block|syntax|javascript|4513903|现在，您可以在需要随机颜色时调用此函数。|4513904|self.view.backgroundColor+=+getRandomColor()|4513905|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|$]]

<p>Make a function to generate random color:</p>

<pre><code>func getRandomColor() -&gt; UIColor {
     //Generate between 0 to 1
     let red:CGFloat = CGFloat(drand48())   
     let green:CGFloat = CGFloat(drand48()) 
     let blue:CGFloat = CGFloat(drand48())  

     return UIColor(red:red, green: green, blue: blue, alpha: 1.0)
}
</code></pre>

<p>Now, you can call this function whenever you need random color.</p>

<pre><code>self.view.backgroundColor = getRandomColor()
</code></pre>


blocks|key|6483|text|对于Swift+4.2|type|unstyled|depth|inlineStyleRanges|entityRanges|data|6484|extension+UIColor+{
++++static+var+random:+UIColor+{
++++++++return+UIColor(
++++++++++++red:+.random(in:+0...1),
++++++++++++green:+.random(in:+0...1),
++++++++++++blue:+.random(in:+0...1),
++++++++++++alpha:+1.0
++++++++)
++++}
}|code-block|syntax|javascript|6485|对于Swift+3和更高版本：|6486|extension+CGFloat+{
++++static+var+random:+CGFloat+{
++++++++return+CGFloat(arc4random())+/+CGFloat(UInt32.max)
++++}
}

extension+UIColor+{
++++static+var+random:+UIColor+{
++++++++return+UIColor(red:+.random,+green:+.random,+blue:+.random,+alpha:+1.0)
++++}
}|6487|用法：|6488|let+myColor:+UIColor+=+.random|6489|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|$]]

<h3>For Swift 4.2</h3>
<pre><code>extension UIColor {
    static var random: UIColor {
        return UIColor(
            red: .random(in: 0...1),
            green: .random(in: 0...1),
            blue: .random(in: 0...1),
            alpha: 1.0
        )
    }
}
</code></pre>
<h3>For Swift 3 and above:</h3>
<pre><code>extension CGFloat {
    static var random: CGFloat {
        return CGFloat(arc4random()) / CGFloat(UInt32.max)
    }
}

extension UIColor {
    static var random: UIColor {
        return UIColor(red: .random, green: .random, blue: .random, alpha: 1.0)
    }
}
</code></pre>
<h3>Usage:</h3>
<pre><code>let myColor: UIColor = .random
</code></pre>


blocks|key|4513947|text|func+anotherGetRandomColor()->UIColor{

++++let+newRed+++=+Double(arc4random_uniform(256))/255.0
++++let+newGreen+=+Double(arc4random_uniform(256))/255.0
++++let+newBlue++=+Double(arc4random_uniform(256))/255.0

++++return+UIColor(red:+CGFloat(newRed),+green:+CGFloat(newGreen),+blue:+CGFloat(newBlue),+alpha:+1.0)
}|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4513948|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>func anotherGetRandomColor()-&gt;UIColor{

    let newRed   = Double(arc4random_uniform(256))/255.0
    let newGreen = Double(arc4random_uniform(256))/255.0
    let newBlue  = Double(arc4random_uniform(256))/255.0

    return UIColor(red: CGFloat(newRed), green: CGFloat(newGreen), blue: CGFloat(newBlue), alpha: 1.0)
}
</code></pre>


blocks|key|6526|text|使用带有内联函数的扩展来生成随机数|type|unstyled|depth|inlineStyleRanges|entityRanges|data|6527|extension+UIColor+{
++++static+func+random()+->+UIColor+{

++++++++func+random()+->+CGFloat+{+return+.random(in:0...1)+}

++++++++return+UIColor(red:+++random(),
+++++++++++++++++++++++green:+random(),
+++++++++++++++++++++++blue:++random(),
+++++++++++++++++++++++alpha:+1.0)
++++}
}|code-block|syntax|javascript|6528|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|$]]

<p>Using an extension with an inline function to generate randoms</p>

<pre><code>extension UIColor {
    static func random() -&gt; UIColor {

        func random() -&gt; CGFloat { return .random(in:0...1) }

        return UIColor(red:   random(),
                       green: random(),
                       blue:  random(),
                       alpha: 1.0)
    }
}
</code></pre>


blocks|key|6539|text|SwiftUI+-+Swift+5|type|unstyled|depth|inlineStyleRanges|entityRanges|data|6540|import+SwiftUI

extension+Color+{
++++static+var+random:+Color+{
++++++++return+Color(red:+.random(in:+0...1),
+++++++++++++++++++++green:+.random(in:+0...1),
+++++++++++++++++++++blue:+.random(in:+0...1))
++++}
}|code-block|syntax|javascript|6541|用法：|6542|let+randomColor:+Color+=+.random|offset|length|style|CODE|6543|entityMap^0|0|0|0|0|W|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]]|$1|G|3|H|5|6|7|S|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|T|8|@$K|U|L|V|M|N]]|9|@]|A|$]]|$1|O|3|-4|5|6|7|W|8|@]|9|@]|A|$]]]|P|$]]

<h2>SwiftUI - Swift 5</h2>
<pre><code>import SwiftUI

extension Color {
    static var random: Color {
        return Color(red: .random(in: 0...1),
                     green: .random(in: 0...1),
                     blue: .random(in: 0...1))
    }
}
</code></pre>
<h2>Usage:</h2>
<p><code>let randomColor: Color = .random</code></p>


<p>How I can make a random color function using Swift?</p>

<pre><code>import UIKit

class ViewController: UIViewController {

    var randomNumber = arc4random_uniform(20)
    var randomColor = arc4random()

    //Color Background randomly
    func colorBackground() {

        // TODO: set a random color
        view.backgroundColor = UIColor.yellow

    }
}
</code></pre>


How to make a random color with Swift

Swift

如何使用Swift创建随机颜色函数？import UIKitclass ViewController: UIViewController {    var randomNumber = arc4random_uniform(20)    var randomColor = arc4random()    //Color...

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