1，直接读取图片中的二维码

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_403_11@

@H_403_11@
@H_403_11@

@H_403_11@

代码如下： @H_403_11@

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import UIKit @H_403_11@

@H_403_11@

class ViewController : UIViewController { @H_403_11@

@H_403_11@

override func viewDidLoad() { @H_403_11@

super .viewDidLoad() @H_403_11@

@H_403_11@

let qrcodeImg = UIImage (named: "codeBg.png" ) @H_403_11@

ciImage: CIImage = CIImage (image:qrcodeImg!)! @H_403_11@

@H_403_11@

context = CIContext (options: nil ) @H_403_11@

detector: CIDetector (ofType: CIDetectorTypeQRCode , @H_403_11@

context: context,options: [ CIDetectorAccuracy CIDetectorAccuracyHigh ]) @H_403_11@

@H_403_11@

features=detector.featuresInImage(ciImage) @H_403_11@

@H_403_11@

print ( "扫描到二维码个数：\(features.count)" ) @H_403_11@

//遍历所有的二维码，并框出 @H_403_11@

for feature in features as ! [ CIQRCodeFeature ] { @H_403_11@

(feature.messageString) @H_403_11@

} @H_403_11@

@H_403_11@

didReceiveMemoryWarning() { @H_403_11@

.didReceiveMemoryWarning() @H_403_11@

} @H_403_11@

} @H_403_11@ @H_403_11@

@H_403_11@ @H_403_11@

控制台输出如下： @H_403_11@

扫描到二维码个数：2
http://www.hangge.com
http://www.hangge.com @H_403_11@ 可以看到两个二维码都成功的读取到了。

@H_403_11@

（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

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import UIKit @H_403_11@

@H_403_11@

class ViewController : UIViewController UIImagePickerControllerDelegate

403_11@

 
         UINavigationControllerDelegate 
         { 
        @H_403_11@

 
          
        @H_403_11@

override func viewDidLoad() { @H_403_11@

super .viewDidLoad() @H_403_11@

} @H_403_11@

@H_403_11@

//选取相册 @H_403_11@

@IBAction fromAlbum(sender: AnyObject ) { @H_403_11@

//判断设置是否支持图片库 @H_403_11@

if UIImagePickerController .isSourceTypeAvailable(. PhotoLibrary ){ @H_403_11@

//初始化图片控制器 @H_403_11@

let picker = UIImagePickerController () @H_403_11@

//设置代理 @H_403_11@

picker.delegate = self @H_403_11@

//指定图片控制器类型 @H_403_11@

picker.sourceType = UIImagePickerControllerSourceType . PhotoLibrary @H_403_11@

//弹出控制器，显示界面 @H_403_11@

self .presentViewController(picker,animated: true

403_11@

() -> Void in @H_403_11@

}) @H_403_11@

} else { @H_403_11@

print ( "读取相册错误" ) @H_403_11@

} @H_403_11@

@H_403_11@

//选择图片成功后代理 @H_403_11@

imagePickerController(picker:

403_11@

didFinishPickingMediaWithInfo info: [ String : ]) { @H_403_11@

@H_403_11@

//获取选择的原图 @H_403_11@

image = info[ UIImagePickerControllerOriginalImage ] as ! UIImage @H_403_11@

@H_403_11@

//二维码读取 @H_403_11@

ciImage: CIImage = CIImage (image:image)! @H_403_11@

context = CIContext (options: nil ) @H_403_11@

detector: CIDetector (ofType: CIDetectorTypeQRCode

403_11@

CIDetectorAccuracy CIDetectorAccuracyHigh ]) @H_403_11@

features=detector.featuresInImage(ciImage) @H_403_11@

"扫描到二维码个数：\(features.count)" ) @H_403_11@

//遍历所有的二维码，并框出 @H_403_11@

for feature in features ! [ CIQRCodeFeature ] { @H_403_11@

(feature.messageString) @H_403_11@

} @H_403_11@

@H_403_11@

//图片控制器退出 @H_403_11@

picker.dismissViewControllerAnimated(

403_11@

() -> Void in @H_403_11@

}) @H_403_11@

} @H_403_11@

@H_403_11@

didReceiveMemoryWarning() { @H_403_11@

.didReceiveMemoryWarning() @H_403_11@

} @H_403_11@

} @H_403_11@ @H_403_11@

@H_403_11@ @H_403_11@
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：

@H_403_11@ @H_403_11@

代码如下：

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import UIKit @H_403_11@

AVFoundation @H_403_11@

@H_403_11@

class ViewController : UIViewController AVCaptureMetadataOutputObjectsDelegate

403_11@

 
          UIAlertViewDelegate 
          { 
         @H_403_11@


            
         @H_403_11@

 
           
          var 
          scanRectView: 
          UIView 
          ! 
         @H_403_11@

device: AVCaptureDevice ! @H_403_11@

input: AVCaptureDeviceInput ! @H_403_11@

output: AVCaptureMetadataOutput ! @H_403_11@

session: AVCaptureSession ! @H_403_11@

preview: AVCaptureVideoPreviewLayer ! @H_403_11@

@H_403_11@

override func viewDidLoad() { @H_403_11@

super .viewDidLoad() @H_403_11@

} @H_403_11@

@H_403_11@

//通过摄像头扫描 @H_403_11@

@IBAction fromCamera(sender: AnyObject ) { @H_403_11@

do{ @H_403_11@

self .device = AVCaptureDevice .defaultDeviceWithMediaType( AVMediaTypeVideo ) @H_403_11@

@H_403_11@

.input = try (device: device) @H_403_11@

@H_403_11@

.output = AVCaptureMetadataOutput () @H_403_11@

output.setMetadataObjectsDelegate(

403_11@

@H_403_11@

.session = () @H_403_11@

if UIScreen .mainScreen().bounds.size.height<500 { @H_403_11@

.session.sessionPreset = AVCaptureSessionPreset640x480 @H_403_11@

} else { @H_403_11@

AVCaptureSessionPresetHigh @H_403_11@

} @H_403_11@

@H_403_11@

.session.addInput( .input) @H_403_11@

.session.addOutput( .output) @H_403_11@

@H_403_11@

.output.MetadataObjectTypes = [ AVMetadataObjectTypeQRCode ] @H_403_11@

@H_403_11@

//计算中间可探测区域 @H_403_11@

let windowSize: CGSize = .mainScreen().bounds.size; @H_403_11@

scanSize: CGSizeMake (windowSize.width*3/4, @H_403_11@

windowSize.width*3/4); @H_403_11@

scanRect: CGRect = CGRectMake ((windowSize.width-scanSize.width)/2, @H_403_11@

(windowSize.height-scanSize.height)/2,scanSize.width,scanSize.height); @H_403_11@

//计算rectOfInterest 注意x,y交换位置 @H_403_11@

scanRect = (scanRect.origin.y/windowSize.height, @H_403_11@

scanRect.origin.x/windowSize.width, @H_403_11@

scanRect.size.height/windowSize.height, @H_403_11@

scanRect.size.width/windowSize.width); @H_403_11@

//设置可探测区域 @H_403_11@

.output.rectOfInterest = scanRect @H_403_11@

@H_403_11@

.preview = AVCaptureVideoPreviewLayer (session: .session) @H_403_11@

.preview.videoGravity = AVLayerVideoGravityResizeAspectFill @H_403_11@

.preview.frame = .mainScreen().bounds @H_403_11@

.view.layer.insertSublayer( .preview,atIndex:0) @H_403_11@

@H_403_11@

//添加中间的探测区域绿框 @H_403_11@

.scanRectView = UIView (); @H_403_11@

.view.addSubview( .scanRectView) @H_403_11@

.scanRectView.frame = CGRectMake (0,scanSize.height); @H_403_11@

.scanRectView.center = CGPointMake ( @H_403_11@

CGRectGetMidX ( UIScreen .mainScreen().bounds), @H_403_11@

CGRectGetMidY .mainScreen().bounds)); @H_403_11@

.scanRectView.layer.borderColor = UIColor .greenColor(). CGColor @H_403_11@

.scanRectView.layer.borderWidth = 1; @H_403_11@

@H_403_11@

//开始捕获 @H_403_11@

.session.startRunning() @H_403_11@

}catch _ as NSError { @H_403_11@

//打印错误消息 @H_403_11@

errorAlert = UIAlertView (title: "提醒"

403_11@

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"

403_11@

delegate:

403_11@

cancelButtonTitle: "确定" ) @H_403_11@

errorAlert.show() @H_403_11@

} @H_403_11@

@H_403_11@

//摄像头捕获 @H_403_11@

captureOutput(captureOutput: AVCaptureOutput !, @H_403_11@

didOutputMetadataObjects MetadataObjects: [ AnyObject ]!, @H_403_11@

fromConnection connection: AVCaptureConnection !) { @H_403_11@

@H_403_11@

stringValue: String ? @H_403_11@

if MetadataObjects.count > 0 { @H_403_11@

MetadataObject = MetadataObjects[0] as ! AVMetadataMachineReadableCodeObject @H_403_11@

stringValue = MetadataObject.stringValue @H_403_11@

@H_403_11@

stringValue != nil { @H_403_11@

.session.stopRunning() @H_403_11@

} @H_403_11@

.session.stopRunning() @H_403_11@

//输出结果 @H_403_11@

alertView = UIAlertView "二维码"

403_11@

) @H_403_11@

alertView.show() @H_403_11@

} @H_403_11@

@H_403_11@

//消息框确认后消失 @H_403_11@

alertView(alertView: Int ) { @H_403_11@

//继续扫描 @H_403_11@

.session.startRunning() @H_403_11@

} @H_403_11@

@H_403_11@

didReceiveMemoryWarning() { @H_403_11@

.didReceiveMemoryWarning() @H_403_11@

} @H_403_11@

} @H_403_11@ @H_403_11@

@H_403_11@ @H_403_11@ @H_403_11@ @H_403_11@
原文出自： www.hangge.com 转载请保留原文链接： http://www.hangge.com/blog/cache/detail_915.html

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