Swift - 二维码QRCode的读取

Swift 2020-06-04

1，直接读取图片中的二维码 @H_502_6@ 使用 CIDetector可以很方便的检测并读取二维码。下面是一个从 UIImage中读取二维码的样例，我们要把图片上所有的二维码信息都打印出来。

@H_502_6@

@H_502_6@ 代码如下：

@H_502_6@

 
        import 
        UIKit 
       
class 
        ViewController 
        : 
        UIViewController 
        { 
       
        override 
        func 
        viewDidLoad() { 
       
super 
        .viewDidLoad() 
       
let 
        qrcodeImg = 
        UIImage 
        (named: 
        "codeBg.png" 
        ) 
       
ciImage: 
        CIImage 
        = 
        CIImage 
        (image:qrcodeImg!)! 
       
context = 
        CIContext 
        (options: 
        nil 
        ) 
       
detector: 
        CIDetector 
        (ofType: 
        CIDetectorTypeQRCode 
        , 
       
        context: context,options: [ 
        CIDetectorAccuracy 
        CIDetectorAccuracyHigh 
        ]) 
       
features=detector.featuresInImage(ciImage) 
       
        print 
        ( 
        "扫描到二维码个数：\(features.count)" 
        ) 
       
        //遍历所有的二维码，并框出 
       
for 
        feature 
        in 
        features 
        as 
        ! [ 
        CiqrCodeFeature 
        ] { 
       
(feature.messageString) 
       
} 
       
} 
       
didReceiveMemoryWarning() { 
       
.didReceiveMemoryWarning() 
       
} 
       
        }

@H_502_6@ 控制台输出如下：

扫描到二维码个数：2
http://www.hangge.com
http://www.hangge.com

可以看到两个二维码都成功的读取到了。 @H_502_6@
@H_502_6@ （注：这个我原来用模拟器一直检测不到二维码，使用真机调试就没问题。感谢网友“落叶”的提醒，模拟器选iphone5s及以上设备也是可以检测到的。）

2，从相册中选择图片读取二维码

 
         import 
         UIKit 
        

           
        
class 
         ViewController 
         : 
         UIViewController 
         ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
         UIImagePickerControllerDelegate 
         ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
        
 
         UINavigationControllerDelegate 
         { 
        
 
          
        
 
         override 
         func 
         viewDidLoad() { 
        
super 
         .viewDidLoad() 
        
 
         } 
        
 
        
 
         //选取相册 
        
@IBAction 
         fromAlbum(sender: 
         AnyObject 
         ) { 
        
//判断设置是否支持图片库 
        
if 
         UIImagePickerController 
         .isSourceTypeAvailable(. 
         PhotoLibrary 
         ){ 
        
//初始化图片控制器 
        
let 
         picker = 
         UIImagePickerController 
         () 
        
//设置代理 
        
picker.delegate = 
         self 
        
//指定图片控制器类型 
        
picker.sourceType = 
         UIImagePickerControllerSourceType 
         . 
         PhotoLibrary 
        
//弹出控制器，显示界面 
        
self 
         .presentViewController(picker,animated: 
         true 
         ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,completion: { 
        
() -> 
         Void 
         in 
        
}) 
        
} 
         else 
         { 
        
 
         print 
         ( 
         "读取相册错误" 
         ) 
        
} 
        
} 
        
 
        
//选择图片成功后代理 
        
imagePickerController(picker: 
         ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
        
didFinishPickingMediawithInfo info: [ 
         String 
         : 
         ]) { 
        

           
        
//获取选择的原图 
        
image = info[ 
         UIImagePickerControllerOriginalImage 
         ] 
         as 
         ! 
         UIImage 
        
 
        
//二维码读取 
        
ciImage: 
         CIImage 
         = 
         CIImage 
         (image:image)! 
        
context = 
         CIContext 
         (options: 
         nil 
         ) 
        
detector: 
         CIDetector 
         (ofType: 
         CIDetectorTypeQRCode 
         ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
        
ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:0px 1em!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none rgb(249,options: [ 
         CIDetectorAccuracy 
         CIDetectorAccuracyHigh 
         ]) 
        
features=detector.featuresInImage(ciImage) 
        
"扫描到二维码个数：\(features.count)" 
         ) 
        
//遍历所有的二维码，并框出 
        
for 
         feature 
         in 
         features 
         ! [ 
         CiqrCodeFeature 
         ] { 
        
(feature.messageString) 
        
} 
        
 
        
//图片控制器退出 
        
picker.dismissViewControllerAnimated( 
         ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,completion: { 
        
() -> 
         Void 
         in 
        
}) 
        
} 
        
 
        
didReceiveMemoryWarning() { 
        
.didReceiveMemoryWarning() 
        
} 
        
 
         } 
        

3，使用摄像头扫描读取二维码
（1）扫描主要使用的是 AVFoundation，用起来方便简单
（2）通过 AVCaptureMetadataOutput的 rectOfInterest属性，可以设置探测探测区域。同时给这个探测区域添加个方框，只有在框中的二维码才会被扫描到。

效果图如下：

代码如下：

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          import 
          UIKit 
         
AVFoundation 
         

            
         
class 
          ViewController 
          : 
          UIViewController 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
          AVCaptureMetadataOutputObjectsDelegate 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
         
 
          UIAlertViewDelegate 
          { 
         

            
         
 
           
          var 
          scanRectView: 
          UIView 
          ! 
         
device: 
          AVCaptureDevice 
          ! 
         
input: 
          AVCaptureDeviceInput 
          ! 
         
output: 
          AVCaptureMetadataOutput 
          ! 
         
session: 
          AVCaptureSession 
          ! 
         
preview: 
          AVCaptureVideoPreviewLayer 
          ! 
         
 
         
override 
          func 
          viewDidLoad() { 
         
super 
          .viewDidLoad() 
         
 
          } 
         
 
         
 
          //通过摄像头扫描 
         
@IBAction 
          fromCamera(sender: 
          AnyObject 
          ) { 
         
do{ 
         
self 
          .device = 
          AVCaptureDevice 
          .defaultDeviceWithMediaType( 
          AVMediaTypeVideo 
          ) 
         
 
         
.input = try 
          (device: device) 
         
 
         
.output = 
          AVCaptureMetadataOutput 
          () 
         
output.setMetadataObjectsDelegate( 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,queue: dispatch_get_main_queue()) 
         
 
         
.session = 
          () 
         
if 
          UIScreen 
          .mainScreen().bounds.size.height<500 { 
         
.session.sessionPreset = 
          AVCaptureSessionPreset640x480 
         
} 
          else 
          { 
         
AVCaptureSessionPresetHigh 
         
} 
         
 
         
.session.addInput( 
          .input) 
         
.session.addOutput( 
          .output) 
         
 
         
.output.MetadataObjectTypes = [ 
          AVMetadataObjectTypeQRCode 
          ] 
         
 
         
//计算中间可探测区域 
         
let 
          windowSize: 
          CGSize 
          = 
          .mainScreen().bounds.size; 
         
scanSize: 
          CGSizeMake 
          (windowSize.width*3/4, 
         
windowSize.width*3/4); 
         
scanRect: 
          CGRect 
          = 
          CGRectMake 
          ((windowSize.width-scanSize.width)/2, 
         
(windowSize.height-scanSize.height)/2,scanSize.width,scanSize.height); 
         
//计算rectOfInterest 注意x,y交换位置 
         
scanRect = 
          (scanRect.origin.y/windowSize.height, 
         
scanRect.origin.x/windowSize.width, 
         
scanRect.size.height/windowSize.height, 
         
scanRect.size.width/windowSize.width); 
         
//设置可探测区域 
         
.output.rectOfInterest = scanRect 
         
 
         
.preview = 
          AVCaptureVideoPreviewLayer 
          (session: 
          .session) 
         
.preview.videoGravity = 
          AVLayerVideoGravityResizeAspectFill 
         
.preview.frame = 
          .mainScreen().bounds 
         
.view.layer.insertSublayer( 
          .preview,atIndex:0) 
         
 
         
//添加中间的探测区域绿框 
         
.scanRectView = 
          UIView 
          (); 
         
.view.addSubview( 
          .scanRectView) 
         
.scanRectView.frame = 
          CGRectMake 
          (0,scanSize.height); 
         
.scanRectView.center = 
          CGPointMake 
          ( 
         
 
          CGRectGetMidX 
          ( 
          UIScreen 
          .mainScreen().bounds), 
         
CGRectGetMidY 
          .mainScreen().bounds)); 
         
.scanRectView.layer.borderColor = 
          UIColor 
          .greenColor(). 
          CGColor 
         
.scanRectView.layer.borderWidth = 1; 
         
 
         
//开始捕获 
         
.session.startRunning() 
         
}catch _ 
          as 
          NSError 
          { 
         
//打印错误消息 
         
errorAlert = 
          UIAlertView 
          (title: 
          "提醒" 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
         
message: 
          "请在iPhone的\"设置-隐私-相机\"选项中,允许本程序访问您的相机" 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
         
delegate: 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas, 
         
cancelButtonTitle: 
          "确定" 
          ) 
         
errorAlert.show() 
         
} 
         
} 
         
 
         
//摄像头捕获 
         
captureOutput(captureOutput: 
          AVCaptureOutput 
          !, 
         
didOutputMetadataObjects MetadataObjects: [ 
          AnyObject 
          ]!, 
         
fromConnection connection: 
          AVCaptureConnection 
          !) { 
         
 
         
stringValue: 
          String 
          ? 
         
if 
          MetadataObjects.count > 0 { 
         
MetadataObject = MetadataObjects[0] 
          as 
          ! 
          AVMetadataMachineReadableCodeObject 
         
stringValue = MetadataObject.stringValue 
         
 
         
stringValue != 
          nil 
          { 
         
.session.stopRunning() 
         
} 
         
} 
         
.session.stopRunning() 
         
//输出结果 
         
alertView = 
          UIAlertView 
          "二维码" 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,message: stringValue, 
         
ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:0px 1em!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:auto!important; background:none rgb(249,cancelButtonTitle: 
          ) 
         
alertView.show() 
         
} 
         
 
         
//消息框确认后消失 
         
alertView(alertView: 
          ottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.5em!important; margin:0px!important; overflow:visible!important; padding:1px 0px!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,willdismissWithButtonIndex buttonIndex: 
          Int 
          ) { 
         
//继续扫描 
         
.session.startRunning() 
         
} 
         
 
         
didReceiveMemoryWarning() { 
         
.didReceiveMemoryWarning() 
         
} 
         
 
          } 
         