【www.bbyears.com--ios】
1，条形码（一维码）的扫描读取
原来写过一篇文章，介绍如何使用摄像头扫描读取二维码：Swift - 二维码QRCode的读取（从图片读取 ，或通过摄像头扫描）要通过摄像头读取条形码，只需要将原来二维码读取代码中 metadataObjectTypes 做如下修改即可：
self.output.metadataObjectTypes = [AVMetadataObjectTypeEAN13Code,
AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypeCode39Code,AVMetadataObjectTypeCode93Code]
2，拉近镜头，改善条形码读取效果
import UIKit
import AVFoundation
class ViewController: UIViewController, AVCaptureMetadataOutputObjectsDelegate,
UIAlertViewDelegate{
var scanRectView:UIView!
var device:AVCaptureDevice!
var input:AVCaptureDeviceInput!
var output:AVCaptureMetadataOutput!
var session:AVCaptureSession!
var preview:AVCaptureVideoPreviewLayer!
override func viewDidLoad() {
super.viewDidLoad()
fromCamera()
}
//通过摄像头扫描
func fromCamera() {
do{
self.device = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo)
self.input = try AVCaptureDeviceInput(device: device)
self.output = AVCaptureMetadataOutput()
output.setMetadataObjectsDelegate(self, queue: dispatch_get_main_queue())
self.session = AVCaptureSession()
if UIScreen.mainScreen().bounds.size.height<500 {
self.session.sessionPreset = AVCaptureSessionPreset640x480
}else{
self.session.sessionPreset = AVCaptureSessionPresetHigh
}
self.session.addInput(self.input)
self.session.addOutput(self.output)
self.output.metadataObjectTypes = [AVMetadataObjectTypeEAN13Code,
AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code,
AVMetadataObjectTypeCode39Code,AVMetadataObjectTypeCode93Code]
//计算中间可探测区域
let windowSize:CGSize = UIScreen.mainScreen().bounds.size;
let scanSize:CGSize = CGSizeMake(windowSize.width*3/4,
windowSize.width*3/4);
var 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 = CGRectMake(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
self.output.rectOfInterest = scanRect
self.preview = AVCaptureVideoPreviewLayer(session:self.session)
self.preview.videoGravity = AVLayerVideoGravityResizeAspectFill
self.preview.frame = UIScreen.mainScreen().bounds
self.view.layer.insertSublayer(self.preview, atIndex:0)
//添加中间的探测区域绿框
self.scanRectView = UIView();
self.view.addSubview(self.scanRectView)
self.scanRectView.frame = CGRectMake(0, 0, scanSize.width, scanSize.height);
self.scanRectView.center = CGPointMake(
CGRectGetMidX(UIScreen.mainScreen().bounds),
CGRectGetMidY(UIScreen.mainScreen().bounds));
self.scanRectView.layer.borderColor = UIColor.greenColor().CGColor
self.scanRectView.layer.borderWidth = 1;
//开始捕获
self.session.startRunning()
//放大
do {
try self.device!.lockForConfiguration()
} catch _ {
NSLog("Error: lockForConfiguration.");
}
self.device!.videoZoomFactor = 1.5
self.device!.unlockForConfiguration()
}catch _ as NSError{
//打印错误消息
let errorAlert = UIAlertView(title: "提醒",
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",
delegate: self,
cancelButtonTitle: "确定")
errorAlert.show()
}
}
//摄像头捕获
func captureOutput(captureOutput: AVCaptureOutput!,
didOutputMetadataObjects metadataObjects: [AnyObject]!,
fromConnection connection: AVCaptureConnection!) {
var stringValue:String?
if metadataObjects.count > 0 {
let metadataObject = metadataObjects[0]
as! AVMetadataMachineReadableCodeObject
stringValue = metadataObject.stringValue
if stringValue != nil{
self.session.stopRunning()
}
}
self.session.stopRunning()
//输出结果
let alertView = UIAlertView(title: "二维码", message: stringValue,
delegate: self, cancelButtonTitle: "确定")
alertView.show()
}
//消息框确认后消失
func alertView(alertView: UIAlertView, willDismissWithButtonIndex buttonIndex: Int) {
//继续扫描
self.session.startRunning()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}