swift详解之二十六-----------CALayer 判断是否点击hitTest 和 contensRect

傷城~ 2022-08-05 08:13 174阅读 0赞

## CALayer 判断是否点击hitTest ##

--------------------

CALayer并不关心任何响应链事件，所以不能直接处理触摸事件或者手势。但是它有一系列的方法帮你处理事件：`containsPoint:`和`hitTest:`。

下来看看这两个方法怎么使用 。

首先来看`containsPoint` ， 首先在界面上拖一个UIView出来 ， 在上面放两份layer 。

ly1.frame = CGRectMake(0, 0, 20, 20)
            ly1.backgroundColor = UIColor.redColor().CGColor
            v1.layer.addSublayer(ly1)
    
    
            ly2.frame = CGRectMake(40, 0, 20, 20)
            ly2.backgroundColor = UIColor.redColor().CGColor
            v1.layer.addSublayer(ly2)

大概就这样的  
![这里写图片描述][20150908211322434]

然后重写`touchesBegan` 方法

override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
            var p = (touches as NSSet).anyObject()?.locationInView(v1);
            p = v1.layer.convertPoint(p!, fromLayer: v1.layer)
    
            //方法1
            if v1.layer.containsPoint(p!) {
                p = ly1.convertPoint(p!, fromLayer: v1.layer)
                if ly1.containsPoint(p!){
                   let alert = UIAlertView(title: "点击了", message: "第一个被点击了", delegate: nil, cancelButtonTitle: "OK")
                    alert.show()
                }
    
                p = ly2.convertPoint(p!, fromLayer: v1.layer)
                if ly2.containsPoint(p!){
                    let alert = UIAlertView(title: "点击了", message: "第二个被点击了", delegate: nil, cancelButtonTitle: "OK")
                    alert.show()
                }
    
            }
     }

效果：  
![这里写图片描述][20150908211659444]

就这样的效果 ， 别的Layer 可以暂时不管

`hitTest` 方法

//方法2
            let p1 = (touches as NSSet).anyObject()?.locationInView(self.v1);
            //p1 = v1.layer.convertPoint(p1!, fromLayer: v1.layer)
            let clickLayer = ly3.hitTest(p1!)
            print(ly3.frame)
            if(clickLayer == ly3){
                let alert = UIAlertView(title: "点击了", message: "第三个被点击了", delegate: nil, cancelButtonTitle: "OK")
                alert.show()
            }
    
            let anoLayer = ly4.hitTest(p1!)
            if(anoLayer == ly4){
                let alert = UIAlertView(title: "点击了", message: "点击了小鸟", delegate: nil, cancelButtonTitle: "OK")
                alert.show()
            }

这个方法方便多了，代码量少多了 ， 以后就用这个了。。。  
看看效果  
![这里写图片描述][20150908211945097]

### contensRect ###

前面讲过者个属性是用来裁剪图片的 ， 用一个示例来看看这个属性的用法

这个图  
![这里写图片描述][20150908212524463]

先在界面上拖写view  
![这里写图片描述][20150908212736773]

拖到控制器

@IBOutlet var digitViews: [UIView]!

一个数组 。

img = UIImage(named: "sz")!
            for item in digitViews{
                item.layer.contents = UIImage(named: "sz")!.CGImage
                item.layer.contentsRect = CGRectMake(0, 0, 0.1, 1.0);
                item.layer.contentsGravity = kCAGravityResizeAspect;
            }
    
    
           let timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: "showTime", userInfo: nil, repeats: true)
    timer.fire()

func showTime(){
    
            let calendar = NSCalendar.currentCalendar()
    //        let unitFlags =
            let comp = calendar.components(NSCalendarUnit.Second , fromDate: NSDate())
    
            setDigit(comp.second%10,ly: digitViews[0])
            setDigit(comp.second/10, ly: digitViews[1])
    
            let comp1 = calendar.components(NSCalendarUnit.Minute , fromDate: NSDate())
            setDigit(comp1.minute%10,ly: digitViews[2])
            setDigit(comp1.minute/10, ly: digitViews[3])
    
            let comp2 = calendar.components(NSCalendarUnit.Hour , fromDate: NSDate())
            setDigit(comp2.hour%10,ly: digitViews[4])
            setDigit(comp2.hour/10, ly: digitViews[5])
        }

func setDigit(t:Int,ly:UIView){
    
            ly.layer.contentsRect = CGRectMake(0.1*CGFloat(t),0,0.1, 1);
        }

效果大家也看到了 ， 就是上面图下面的那个电子表  
![这里写图片描述][20150908213057739]

源代码：[https://github.com/smalldu/SwiftStudy][https_github.com_smalldu_SwiftStudy]

> 学习iOS，有他就够了，[小码哥视频，传智、黑马、各种swift书籍][swift]

[20150908211322434]: /images/20220731/c9441b7eb88c4d7f904e888c5c1be2e6.png
[20150908211659444]: /images/20220731/b2edc7703ff04603a5c872c5439aaeba.png
[20150908211945097]: /images/20220731/2f43c36bed8d40f7bd09fbe3c89e732f.png
[20150908212524463]: /images/20220731/e9a980400a5e45d78cefaeb9c4d9d45f.png
[20150908212736773]: /images/20220731/c169635ffc5144e2bf73910fb0ab477f.png
[20150908213057739]: /images/20220731/99c72eefeac14a21ab81ff9503f09e47.png
[https_github.com_smalldu_SwiftStudy]: https://github.com/smalldu/SwiftStudy
[swift]: https://item.taobao.com/item.htm?spm=a230r.1.14.85.JFN9U2&id=529819836478&ns=1&abbucket=7#detail