在开发中，我们有时需要生成一些随机的颜色。但 UIColor 没有提供方法或属性来直接获取随机颜色，这里对其进行扩展，方便使用。
1，扩展UIColor，增加随机颜色属性
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extension
UIColor
{
//返回随机颜色
class
var
randomColor:
UIColor
{
get
{
let
red =
CGFloat
(arc4random()%256)/255.0
let
green =
CGFloat
(arc4random()%256)/255.0
let
blue =
CGFloat
(arc4random()%256)/255.0
return
UIColor
(red: red, green: green, blue: blue, alpha: 1.0)
}
}
}
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2，使用样例
这里我们使用随机颜色来创建一个马赛克墙
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import
UIKit
class
ViewController
:
UIViewController
{
override
func
viewDidLoad() {
super
.viewDidLoad()
//马赛克宽度
let
itemWidth = 5
//行数
let
rowNums =
Int
(
self
.view.bounds.height)/itemWidth
//列数
let
colNums =
Int
(
self
.view.bounds.width)/itemWidth
for
i
in
0...rowNums {
for
j
in
0...colNums{
let
item =
UIView
(frame:
CGRect
(x: j*itemWidth, y: i*itemWidth,
width: itemWidth, height: itemWidth))
//使用随机颜色
item.backgroundColor =
UIColor
.randomColor
self
.view.addSubview(item)
}
}
}
override
func
didReceiveMemoryWarning() {
super
.didReceiveMemoryWarning()
}
}
extension
UIColor
{
//返回随机颜色
class
var
randomColor:
UIColor
{
get
{
let
red =
CGFloat
(arc4random()%256)/255.0
let
green =
CGFloat
(arc4random()%256)/255.0
let
blue =
CGFloat
(arc4random()%256)/255.0
return
UIColor
(red: red, green: green, blue: blue, alpha: 1.0)
}
}
}
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