实现iOS原生二维码扫描

项目需求要是用到二维码扫描，这次使用的是AVFoundation框架实现。相对于ZBar和ZXing效率更高（其次这两个库貌似也没有人维护了）、而且现在好多app也只都支持iOS7.0及以上系统。

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Demo地址：
github地址

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效果图

IMG_1352.PNG IMG_1353.PNG

好了现在就来说说怎么实现吧

1.定义一个类QRCodeReaderView类

   #import <UIKit/UIKit.h>

  @protocol QRCodeReaderViewDelegate <NSObject>
  - (void)readerScanResult:(NSString *)result;
  @end

  @interface QRCodeReaderView : UIView

  @property (nonatomic, weak)id<QRCodeReaderViewDelegate> delegate;
  @property (nonatomic,copy)UIImageView * readLineView;
  @property (nonatomic,assign)BOOL is_Anmotion;
  @property (nonatomic,assign)BOOL is_AnmotionFinished;

  //开启关闭扫描
  - (void)start;
  - (void)stop;

  - (void)loopDrawLine;//初始化扫描线

  @end

2.看看.m的实现

 #import "QRCodeReaderView.h"
 #import <AVFoundation/AVFoundation.h>

 #define DeviceMaxHeight ([UIScreen      mainScreen].bounds.size.height)
 #define DeviceMaxWidth ([UIScreen      mainScreen].bounds.size.width)
 #define widthRate DeviceMaxWidth/320

 #define contentTitleColorStr @"666666" //正文颜色较深
 
 @interface QRCodeReaderView ()  <AVCaptureMetadataOutputObjectsDelegate>
 {
     //采集流
     AVCaptureSession * session;
     NSTimer * countTime;
 }
 @property (nonatomic, strong) CAShapeLayer *overlay;
 @end

 @implementation QRCodeReaderView

 - (id)initWithFrame:(CGRect)frame
 {
     if ((self = [super initWithFrame:frame])) {
         //初始化
         [self instanceDevice];
   }

   return self;
 }     

初始化并创建

 - (void)instanceDevice
 {
     //扫描区域
     UIImage *hbImage=[UIImage imageNamed:@"scanscanBg"];
     UIImageView * scanZomeBack=[[UIImageView alloc] init];
     scanZomeBack.backgroundColor = [UIColor clearColor];
     scanZomeBack.layer.borderColor = [UIColor whiteColor].CGColor;
     scanZomeBack.layer.borderWidth = 2.5;
     scanZomeBack.image = hbImage;
     //添加一个背景图片
     CGRect mImagerect = CGRectMake(60*widthRate, (DeviceMaxHeight-200*widthRate)/2, 200*widthRate,      200*widthRate);
     [scanZomeBack setFrame:mImagerect];
     CGRect scanCrop=[self getScanCrop:mImagerect readerViewBounds:self.frame];
     [self addSubview:scanZomeBack];

     //获取摄像设备
     AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
     //创建输入流
     AVCaptureDeviceInput * input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
     //创建输出流
     AVCaptureMetadataOutput * output =      [[AVCaptureMetadataOutput alloc]init];
     //设置代理 在主线程里刷新
     [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
output.rectOfInterest = scanCrop;

     //初始化链接对象
     session = [[AVCaptureSession alloc]init];
     //高质量采集率
     [session setSessionPreset:AVCaptureSessionPresetHigh];
     if (input) {
         [session addInput:input];
     }
     if (output) {
         [session addOutput:output];
         //设置扫码支持的编码格式(如下设置条形码和二维码兼容)
         NSMutableArray *a = [[NSMutableArray alloc] init];
         if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeQRCode]) {
             [a addObject:AVMetadataObjectTypeQRCode];
         }
         if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeEAN13Code]) {
             [a addObject:AVMetadataObjectTypeEAN13Code];
         }
         if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeEAN8Code]) {
             [a addObject:AVMetadataObjectTypeEAN8Code];
         }
         if ([output.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeCode128Code]) {
             [a addObject:AVMetadataObjectTypeCode128Code];
         }
         output.metadataObjectTypes=a;
     }

     AVCaptureVideoPreviewLayer * layer =      [AVCaptureVideoPreviewLayer layerWithSession:session];
     layer.videoGravity=AVLayerVideoGravityResizeAspectFill;
     layer.frame=self.layer.bounds;
     [self.layer insertSublayer:layer atIndex:0];

     [self setOverlayPickerView:self];

     //开始捕获
     [session startRunning];

     }

扫描线条

 -(void)loopDrawLine
 {
     _is_AnmotionFinished = NO;
     CGRect rect = CGRectMake(60*widthRate,      (DeviceMaxHeight-200*widthRate)/2, 200*widthRate, 2);
     if (_readLineView) {
         _readLineView.alpha = 1;
         _readLineView.frame = rect;
     }
     else{
         _readLineView = [[UIImageView alloc] initWithFrame:rect];
         [_readLineView setImage:[UIImage imageNamed:@"scanLine"]];
         [self addSubview:_readLineView];
     }

     [UIView animateWithDuration:1.5 animations:^{
         //修改fream的代码写在这里
         _readLineView.frame =CGRectMake(60*widthRate, (DeviceMaxHeight-200*widthRate)/2+200*widthRate-5, 200*widthRate, 2);
} completion:^(BOOL finished) {
         if (!_is_Anmotion) {
             [self loopDrawLine];
         }
         _is_AnmotionFinished = YES;
     }];
 }

 - (void)setOverlayPickerView:(QRCodeReaderView *)reader
 {

     CGFloat wid = 60*widthRate;
     CGFloat heih = (DeviceMaxHeight-200*widthRate)/2;

     //最上部view
     CGFloat alpha = 0.6;
     UIView* upView = [[UIView alloc]      initWithFrame:CGRectMake(0, 0, DeviceMaxWidth, heih)];
     upView.alpha = alpha;
     upView.backgroundColor = [self colorFromHexRGB:contentTitleColorStr];
     [reader addSubview:upView];

     //用于说明的label
     UILabel * labIntroudction= [[UILabel alloc] init];
     labIntroudction.backgroundColor = [UIColor clearColor];
     labIntroudction.frame=CGRectMake(0, 64+(heih-64-50*widthRate)/2, DeviceMaxWidth, 50*widthRate);
     labIntroudction.textAlignment = NSTextAlignmentCenter;
     labIntroudction.textColor=[UIColor whiteColor];
     labIntroudction.text=@"将二维码放入框中，即自动扫描";
     [upView addSubview:labIntroudction];

     //左侧的view
     UIView * cLeftView = [[UIView alloc] initWithFrame:CGRectMake(0, heih, wid, 200*widthRate)];
     cLeftView.alpha = alpha;
     cLeftView.backgroundColor = [self colorFromHexRGB:contentTitleColorStr];
     [reader addSubview:cLeftView];

     //右侧的view
     UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(DeviceMaxWidth-wid, heih, wid, 200*widthRate)];
     rightView.alpha = alpha;
     rightView.backgroundColor = [self colorFromHexRGB:contentTitleColorStr];
     [reader addSubview:rightView];

     //底部view
     UIView * downView = [[UIView alloc] initWithFrame:CGRectMake(0, heih+200*widthRate, DeviceMaxWidth, DeviceMaxHeight - heih-200*widthRate)];
     downView.alpha = alpha;
     downView.backgroundColor = [self      colorFromHexRGB:contentTitleColorStr];
     [reader addSubview:downView];

 - (void)turnBtnEvent:(UIButton *)button_
 {
     button_.selected = !button_.selected;
     if (button_.selected) {
         [self turnTorchOn:YES];
     }
     else{
         [self turnTorchOn:NO];
     }

 }

扫描区域

-(CGRect)getScanCrop:(CGRect)rect readerViewBounds:         (CGRect)readerViewBounds
 {

         CGFloat x,y,width,height;
         x = (CGRectGetHeight(readerViewBounds)-CGRectGetHeight(rect))/2/CGRectGetHeight(readerViewBounds);
         y = (CGRectGetWidth(readerViewBounds)-CGRectGetWidth(rect))/2/CGRectGetWidth(readerViewBounds);
         width = CGRectGetHeight(rect)/CGRectGetHeight(readerViewBounds);
         height = CGRectGetWidth(rect)/CGRectGetWidth(readerViewBounds);

         return CGRectMake(x, y, width, height);

}

开始扫描

- (void)start
  {
    [session startRunning];
  }

停止扫描

- (void)stop
{
   [session stopRunning];
}

扫描结果

 - (void)captureOutput:(AVCaptureOutput *)captureOutput      didOutputMetadataObjects:(NSArray *)metadataObjects        fromConnection:(AVCaptureConnection *)connection
{
  if (metadataObjects && metadataObjects.count>0) {
     AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex : 0 ];
     //输出扫描字符串
     if (_delegate && [_delegate respondsToSelector:@selector(readerScanResult:)]) {
        [_delegate readerScanResult:metadataObject.stringValue];
    }
}