iOS 二维码扫描相关功能实现

写在前面

最近项目要实现相机扫描二维码功能，具体要求：1、扫描框 2、扫描动画 3、相册识别二维码 4、声音反馈。

记得之前用过三方库做过类似功能，但是也是知其然不知其所以然，然后今天自己用原生api简单封装了一个二维码扫描控件。

项目结构介绍

控件封装后主要结构如图：

如图中代码目录，vender里面放的是UIView+Frame分类，Resource里面放的是图片声音资源，TZImagePickerController是第三方相册，用来获取相册中的二维码识别的。主要的就是以QR开头的文件，我们具体说一说。

QRCode.h

这个文件主要放的是各个文件的头文件，方便在各处调用

#import "QRCodeScanManager.h"
#import #import "QRLightManager.h"
#import "QRCodeScanView.h"
#import "QRCodeHelper.h"

QRLightManager

这个类是用来开启关闭闪光灯的

/**
 打开手电筒
 */
+ (void)openFlashLight;
/**
 关闭手电筒
 */
+ (void)closeFlashLight;

#pragma mark 打开手电筒
+ (void)openFlashLight {
 AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
 NSError *error = nil;
 if ([captureDevice hasTorch]) {
  BOOL locked = [captureDevice lockForConfiguration:&error];
  if (locked) {
   captureDevice.torchMode = AVCaptureTorchModeOn;
   [captureDevice unlockForConfiguration];
  }
 }
}
#pragma mark 关闭手电筒
+ (void)closeFlashLight {
 AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
 if ([device hasTorch]) {
  [device lockForConfiguration:nil];
  [device setTorchMode:AVCaptureTorchModeOff];
  [device unlockForConfiguration];
 }
}

QRCodeScanView

这个类是将这个界面单独封装出来，便于自定义

在.h文件中有个枚举用来标识二维码扫描四周角标的位置：

typedef enum : NSUInteger {
 CornerLoactionDefault,//默认与边框同中心点
 CornerLoactionInside,//在边框线内部
 CornerLoactionOutside,//在边框线外部
} CornerLoaction;

自定义view各个属性：

@property (nonatomic, strong) UIColor *borderColor;/** 边框颜色*/
@property (nonatomic, assign) CornerLoaction cornerLocation;/** 边角位置 默认default*/
@property (nonatomic, strong) UIColor *cornerColor;/** 边角颜色 默认正保蓝#32d2dc*/
@property (nonatomic, assign) CGFloat cornerWidth;/** 边角宽度 默认2.f*/
@property (nonatomic, assign) CGFloat backgroundAlpha;/** 扫描区周边颜色的alpha 默认0.5*/
@property (nonatomic, assign) CGFloat timeInterval;/** 扫描间隔 默认0.02*/
@property (nonatomic, strong) UIButton *lightBtn;/** 闪光灯*/

暴露外部调用的方法：

/**
 添加定时器
 */
- (void)addTimer;
/**
 移除定时器
 */
- (void)removeTimer;
/**
 根据灯光判断
 */
- (void)lightBtnChangeWithBrightnessValue:(CGFloat)brightnessValue;

初始化默认值：

- (void)initilize {
 self.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.5];
 self.borderColor = [UIColor whiteColor];
 _cornerLocation = CornerLoactionDefault;
 _cornerColor = [UIColor colorWithRed:50/255.0f green:210/255.0f blue:220/255.0f alpha:1.0];
 _cornerWidth = 2.0;
 self.timeInterval = 0.02;
 _backgroundAlpha = 0.5;

 [self addSubview:self.lightBtn];
}

重写view的drawRect方法，在这个方法里面绘制scanView的边框和边角

//空白区域设置
 [[[UIColor blackColor] colorWithAlphaComponent:self.backgroundAlpha] setFill];
 UIRectFill(rect);
 //获取上下文，并设置混合模式 -> kCGBlendModeDestinationOut
 CGContextRef context = UIGraphicsGetCurrentContext();
 CGContextSetBlendMode(context, kCGBlendModeDestinationOut);
 //设置空白区
 UIBezierPath *bezierPath = [UIBezierPath bezierPathWithRect:CGRectMake(borderX + 0.5 * borderLineW, borderY+ 0.5 * borderLineW, borderW - borderLineW, borderH - borderLineW)];
 [bezierPath fill];
 //执行混合模式
 CGContextSetBlendMode(context, kCGBlendModeNormal);

 //边框设置
 UIBezierPath *borderPath = [UIBezierPath bezierPathWithRect:CGRectMake(borderX, borderY, borderW, borderH)];
 borderPath.lineCapStyle = kCGLineCapButt;
 borderPath.lineWidth = borderLineW;
 [self.borderColor set];
 [borderPath stroke];

 CGFloat cornerLength = 20;
 //左上角小图标
 UIBezierPath *leftTopPath = [UIBezierPath bezierPath];
 leftTopPath.lineWidth = self.cornerWidth;
 [self.cornerColor set];

 CGFloat insideExcess = fabs(0.5 * (self.cornerWidth - borderLineW));
 CGFloat outsideExcess = 0.5 * (borderLineW + self.cornerWidth);
 if (self.cornerLocation == CornerLoactionInside) {
  [leftTopPath moveToPoint:CGPointMake(borderX + insideExcess, borderY + cornerLength + insideExcess)];
  [leftTopPath addLineToPoint:CGPointMake(borderX + insideExcess, borderY + insideExcess)];
  [leftTopPath addLineToPoint:CGPointMake(borderX + cornerLength + insideExcess, borderY + insideExcess)];
 } else if (self.cornerLocation == CornerLoactionOutside) {
  [leftTopPath moveToPoint:CGPointMake(borderX - outsideExcess, borderY + cornerLength - outsideExcess)];
  [leftTopPath addLineToPoint:CGPointMake(borderX - outsideExcess, borderY - outsideExcess)];
  [leftTopPath addLineToPoint:CGPointMake(borderX + cornerLength - outsideExcess, borderY - outsideExcess)];
 } else {
  [leftTopPath moveToPoint:CGPointMake(borderX, borderY + cornerLength)];
  [leftTopPath addLineToPoint:CGPointMake(borderX, borderY)];
  [leftTopPath addLineToPoint:CGPointMake(borderX + cornerLength, borderY)];
 }
 [leftTopPath stroke];

增加定时器以及开始动画：

- (void)addTimer {
 [self addSubview:self.scanningLine];
 self.timer = [NSTimer timerWithTimeInterval:self.timeInterval target:self selector:@selector(beginAnimaiton) userInfo:nil repeats:YES];
 [[NSRunLoop mainRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];
}
#pragma mark 动画
- (void)beginAnimaiton {
 static BOOL isOrignPostion = YES;

 if (isOrignPostion) {
  _scanningLine.y = 0;
  isOrignPostion = NO;
  [UIView animateWithDuration:self.timeInterval animations:^{
   self->_scanningLine.y += 2;
  } completion:nil];
 } else {
  if (_scanningLine.frame.origin.y >= 0) {
   CGFloat scanContent_MaxY = self.frame.size.width;
   if (_scanningLine.y >= scanContent_MaxY - 10) {
    _scanningLine.y = 0;
    isOrignPostion = YES;
   } else {
    [UIView animateWithDuration:0.02 animations:^{
     self->_scanningLine.y += 2;

    } completion:nil];
   }
  } else {
   isOrignPostion = !isOrignPostion;
  }
 }
}

闪光灯按钮点击事件，开启关闭闪光灯:

- (void)lightBtnClick:(UIButton *)btn {
 btn.selected = !btn.selected;
 if (btn.selected) {
  [QRLightManager openFlashLight];
 } else {
  [QRLightManager closeFlashLight];
 }
}

QRCodeScanManager

这个单例用来控制所有的关于二维码扫描的事件

初始开启session 会话

//设置二维码读取率 数据类型 当前控制器
- (void)setupSessionPreset:(NSString *)sessionPreset metadataObjectTypes:(NSArray *)metadataObjectTypes currentController:(UIViewController *)currentController {
 if (sessionPreset == nil || metadataObjectTypes == nil || currentController == nil) {
  NSException *excp = [NSException exceptionWithName:@"excp" reason:@"setupSessionPreset:metadataObjectTypes:currentController: 方法中的 sessionPreset 参数不能为空" userInfo:nil];
  [excp raise];
 }

 //1、获取摄像设备
 AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

 //2、创建设备输入流
 AVCaptureDeviceInput *deviceInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];

 //3、创建数据输出流
 AVCaptureMetadataOutput *metadataOutput = [[AVCaptureMetadataOutput alloc] init];
 [metadataOutput setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

 //3(1)、创建设备输出流
 self.videoDataOutput = [[AVCaptureVideoDataOutput alloc] init];
 [_videoDataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];

 // 设置扫描范围（每一个取值0～1，以屏幕右上角为坐标原点）
 // 注：微信二维码的扫描范围是整个屏幕，这里并没有做处理（可不用设置）; 如需限制扫描范围，打开下一句注释代码并进行相应调试
 // metadataOutput.rectOfInterest = CGRectMake(0.05, 0.2, 0.7, 0.6);

 //4、创建会话对象
 _session = [[AVCaptureSession alloc] init];
 //会话采集率：AVCaptureSessionPresetHigh
 _session.sessionPreset = sessionPreset;

 //5、添加设备输出流到会话对象
 [_session addOutput:metadataOutput];
 //5(1)添加设备输出流到会话对象；与3(1)构成识别光纤强弱
 [_session addOutput:_videoDataOutput];

 //6、添加设备输入流到会话对象
 [_session addInput:deviceInput];

 //7、设置数据输出类型，需要将数据输出添加到会话后，才能指定元数据类型，否则会报错
 // 设置扫码支持的编码格式(如下设置条形码和二维码兼容)
 // @[AVMetadataObjectTypeQRCode, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code]
 metadataOutput.metadataObjectTypes = metadataObjectTypes;

 //8、实例化预览图层，传递_session是为了告诉图层将来显示什么内容
 _videoPreviewLayer = [AVCaptureVideoPreviewLayer layerWithSession:_session];
 //保持纵横比；填充层边界
 _videoPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;
 CGFloat x = 0;
 CGFloat y = 0;
 CGFloat w = [UIScreen mainScreen].bounds.size.width;
 CGFloat h = [UIScreen mainScreen].bounds.size.height;
 _videoPreviewLayer.frame = CGRectMake(x, y, w, h);
 [currentController.view.layer insertSublayer:_videoPreviewLayer atIndex:0];

 //9、启动会话
 [_session startRunning];

}

block：

typedef void(^GetBrightnessBlock)(CGFloat brightness);//用来向外部传递捕获到的亮度值以便于识别何时开启闪光灯，
typedef void(^ScanBlock)(NSArray *metadataObjects);//捕获到的结果集合
//亮度回调
- (void)brightnessChange:(GetBrightnessBlock)getBrightnessBlock;
//扫描结果
- (void)scanResult:(ScanBlock)scanBlock;

- (void)startRunning {
 [_session startRunning];
}
- (void)stopRunning {
 [_session stopRunning];
}

需要遵循：/**
 重置根据光线强弱值打开手电筒 delegate方法
 */
- (void)resetSampleBufferDelegate;
/**
 取消根据光线强弱值打开手电筒的delegate方法
 */
- (void)cancelSampleBufferDelegate;
- (void)resetSampleBufferDelegate {
 [_videoDataOutput setSampleBufferDelegate:self queue:dispatch_get_main_queue()];
}
- (void)cancelSampleBufferDelegate {
 [_videoDataOutput setSampleBufferDelegate:nil queue:dispatch_get_main_queue()];
}

#pragma mark 播放扫描提示音
- (void)playSoundName:(NSString *)name {
 NSString *audioFile = [[NSBundle mainBundle] pathForResource:name ofType:nil];
 NSURL *fileUrl = [NSURL fileURLWithPath:audioFile];
 SystemSoundID soundID = 0;
 AudioServicesCreateSystemSoundID((__bridge CFURLRef)(fileUrl), &soundID);
 AudioServicesAddSystemSoundCompletion(soundID, NULL, NULL, soundCompleteCallback, NULL);
 AudioServicesPlaySystemSound(soundID); // 播放音效
}
void soundCompleteCallback(SystemSoundID soundID, void *clientData){

}

注：这里只是截取部分重要代码，具体功能我会将代码放到GitHub上，代码里注释也写的很明白

使用功能

开启、结束定时器

开启、关闭session会话

启用、移除sampleBuffer代理

- (void)viewWillAppear:(BOOL)animated {
 [super viewWillAppear:animated];
 [self.scanView addTimer];
 [_scanManager startRunning];
 [_scanManager resetSampleBufferDelegate];
}
- (void)viewWillDisappear:(BOOL)animated {
 [super viewWillDisappear:animated];
 [self.scanView removeTimer];
 [_scanManager stopRunning];
 [_scanManager cancelSampleBufferDelegate];
}

初始化scanManager

- (void)setupScanManager {
 self.scanManager = [QRCodeScanManager sharedManager];

 NSArray *arr = @[AVMetadataObjectTypeQRCode, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code];
 [_scanManager setupSessionPreset:AVCaptureSessionPreset1920x1080 metadataObjectTypes:arr currentController:self];

 __weak __typeof(self)weakSelf = self;
 //光扫描结果回调
 [_scanManager scanResult:^(NSArray *metadataObjects) {
  if (metadataObjects != nil && metadataObjects.count > 0) {
   [weakSelf.scanManager playSoundName:@"sound.caf"];
   //obj 为扫描结果
   AVMetadataMachineReadableCodeObject *obj = metadataObjects[0];
   NSString *url = [obj stringValue];
   NSLog(@"---url = :%@", url);
  } else {
   NSLog(@"暂未识别出扫描的二维码");
  }
 }];

 //光纤变化回调
 [_scanManager brightnessChange:^(CGFloat brightness) {
  [weakSelf.scanView lightBtnChangeWithBrightnessValue:brightness];
 }];

}

从相册识别二维码：

//借助第三方相册
- (void)albumBtnClick {
 TZImagePickerController *pickerController = [[TZImagePickerController alloc] initWithMaxImagesCount:1 delegate:self];

 __weak __typeof(self)weakSelf = self;

 [pickerController setDidFinishPickingPhotosHandle:^(NSArray *photos, NSArray *assets, BOOL isSelectOriginalPhoto) {
  UIImage *image = photos[0];
  // CIDetector(CIDetector可用于人脸识别)进行图片解析，从而使我们可以便捷的从相册中获取到二维码
  // 声明一个 CIDetector，并设定识别类型 CIDetectorTypeQRCode
  // 识别精度
  CIDetector *detector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:nil options:@{CIDetectorAccuracy:CIDetectorAccuracyHigh}];

  //取得识别结果
  NSArray *features = [detector featuresInImage:[CIImage imageWithCGImage:image.CGImage]];

  NSString *resultStr;
  if (features.count == 0) {
   NSLog(@"暂未识别出二维码");
  } else {
   for (int index = 0; index < [features count]; index++) {
    CIQRCodeFeature *feature = [features objectAtIndex:index];
    resultStr = feature.messageString;
   }
   NSLog(@"---url:%@", resultStr);
  }
 }];
 [self presentViewController:pickerController animated:YES completion:nil];
}

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