iOS 二维码生成及扫码详解及实例代码

/** 
 * @author 半  饱, 15-12-18 
 * 
 * @brief 生成二维码图片 
 * 
 * @param code  生成二维码图片内容 
 * @param width 二维码图片宽度 
 * @param height 二维码图片高度 
 * 
 * @return 返回UIImage对象 
 */ 
- (UIImage *)generateQRCode:(NSString *)code width:(CGFloat)width height:(CGFloat)height { 
  CIImage *qrcodeImage; 
  NSData *data = [code dataUsingEncoding:NSISOLatin1StringEncoding allowLossyConversion:false]; 
  CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; 
   
  [filter setValue:data forKey:@"inputMessage"]; 
  [filter setValue:@"H" forKey:@"inputCorrectionLevel"]; 
  qrcodeImage = [filter outputImage]; 
   
  CGFloat scaleX = width / qrcodeImage.extent.size.width; 
  CGFloat scaleY = height / qrcodeImage.extent.size.height; 
  CIImage *transformedImage = [qrcodeImage imageByApplyingTransform:CGAffineTransformScale(CGAffineTransformIdentity, scaleX, scaleY)]; 
   
  return [UIImage imageWithCIImage:transformedImage]; 
} 

#import <AVFoundation/AVFoundation.h> 
 
static const float lightWidth = 240.f; 
static const float lightHeight = 240.f; 
static const float crossLineWidth = 2.f; 
static const float crossLineHeight = 15.f; 
 
@interface BBScanCodeViewController ()<AVCaptureMetadataOutputObjectsDelegate> { 
  float leftWith; 
  float topHeight; 
} 
@property (strong , nonatomic ) AVCaptureDevice *captureDevice; 
@property (strong , nonatomic ) AVCaptureDeviceInput *captureInput; 
@property (strong , nonatomic ) AVCaptureMetadataOutput *captureOutput; 
@property (strong , nonatomic ) AVCaptureSession *captureSession; 
@property (strong , nonatomic ) AVCaptureVideoPreviewLayer *capturePreview; 
 
@property (strong,nonatomic) UIButton *flashLightBtn; 
@property (strong,nonatomic) UIImageView *lineImageView; 
 
@end 
 
@implementation BBScanCodeViewController 
@synthesize captureDevice = _captureDevice; 
@synthesize captureInput = _captureInput; 
@synthesize captureOutput = _captureOutput; 
@synthesize capturePreview = _capturePreview; 
@synthesize captureSession = _captureSession; 
@synthesize delegate = _delegate; 
@synthesize isRectScan = _isRectScan; 
@synthesize lineImageView = _lineImageView; 
@synthesize flashLightBtn = _flashLightBtn; 
- (void)viewDidLoad { 
   
  [super viewDidLoad]; 
  self.isShowNavigationItem = YES; 
  CGRect screenRect = [UIScreen mainScreen].bounds; 
  leftWith = (screenRect.size.width - lightWidth) / 2; 
  topHeight =(screenRect.size.height - lightHeight) / 2; 
   
#if !TARGET_IPHONE_SIMULATOR 
  [self initScanCode]; 
#endif 
  [self initLayer]; 
  [self initViewControl]; 
   
   
 
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(willResignActiveNotification) name:UIApplicationWillResignActiveNotification object:nil]; //监听是否触发home键挂起程序. 
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didBecomeActiveNotification) name:UIApplicationDidBecomeActiveNotification object:nil]; //监听是否重新进入程序程序. 
} 
 
-(void)viewWillDisappear:(BOOL)animated { 
   [self stopScanCode]; 
  [super viewWillDisappear:animated]; 
} 
 
- (void)willResignActiveNotification { 
  _flashLightBtn.selected = NO; 
} 
- (void)didBecomeActiveNotification { 
 
} 
//加载界面上的控件，如：加上闪光灯按钮等 
- (void)initViewControl { 
 
  @autoreleasepool { 
    _flashLightBtn = [UIButton buttonWithType:UIButtonTypeCustom]; 
    [_flashLightBtn setImage:[UIImage imageNamed:@"OpenFlashLight.png"] forState:UIControlStateNormal]; 
    [_flashLightBtn setImage:[UIImage imageNamed:@"CloseFlashLight.png"] forState:UIControlStateSelected]; 
    _flashLightBtn.frame = CGRectMake(leftWith, 80.f, 30.f, 30.f); 
    [_flashLightBtn addTarget:self action:@selector(systemFlashLight) forControlEvents:UIControlEventTouchUpInside]; 
    [self.view addSubview:_flashLightBtn]; 
     
    _lineImageView = [[UIImageView alloc] initWithImage:nil]; 
    _lineImageView.backgroundColor = [UIColor greenColor]; 
    _lineImageView.frame = CGRectMake(leftWith, topHeight, lightWidth, 2); 
    [self.view addSubview:_lineImageView]; 
    [self scanLineAnimation]; 
  } 
   
} 
 
- (void)scanLineAnimation { 
  [UIView beginAnimations:nil context:nil]; 
  [UIView setAnimationDuration:4.f]; 
  //设置代理 
  [UIView setAnimationDelegate:self]; 
  //设置动画执行完毕调用的事件 
  [UIView setAnimationDidStopSelector:@selector(didViewAnimation)]; 
  _lineImageView.frame = CGRectMake(leftWith,topHeight + lightHeight-2,lightWidth,2); 
  [UIView commitAnimations]; 
 
} 
 
-(void)didViewAnimation { 
//  self.navigationController 
  _lineImageView.frame = CGRectMake(leftWith, topHeight, lightWidth, 2); 
  [self scanLineAnimation]; 
} 
 
- (void)insertLayerWithFrame:(CGRect)frame withBackgroundColor:(UIColor *)backgroundColor { 
  @autoreleasepool { 
    CALayer *layer = [CALayer layer]; 
    layer.backgroundColor = backgroundColor.CGColor; 
    layer.frame = frame; 
    [self.view.layer addSublayer:layer]; 
  } 
} 
//初始化layer层，绘制半透明区域 
-(void) initLayer { 
  //公共参数 
  UIColor *fillColor = [UIColor colorWithRed:0xae/255.f green:0xae/255.f blue:0xae/255.f alpha:0.4]; 
  UIColor *crossColor = [UIColor greenColor]; 
  CGRect screenRect = [UIScreen mainScreen].bounds; 
  [self insertLayerWithFrame:CGRectMake(0, 0, leftWith, screenRect.size.height) withBackgroundColor:fillColor]; 
  [self insertLayerWithFrame:CGRectMake(leftWith, 0, lightWidth, topHeight) withBackgroundColor:fillColor]; 
  [self insertLayerWithFrame:CGRectMake(leftWith + lightWidth, 0, leftWith, screenRect.size.height) withBackgroundColor:fillColor]; 
  [self insertLayerWithFrame:CGRectMake(leftWith, topHeight + lightHeight, lightWidth, topHeight) withBackgroundColor:fillColor]; 
   
   
  [self insertLayerWithFrame:CGRectMake(leftWith, topHeight, crossLineWidth, crossLineHeight) withBackgroundColor:crossColor]; 
  [self insertLayerWithFrame:CGRectMake(leftWith, topHeight, crossLineHeight, crossLineWidth) withBackgroundColor:crossColor]; 
   
  [self insertLayerWithFrame:CGRectMake(leftWith + lightWidth - crossLineHeight, topHeight, crossLineHeight, crossLineWidth) withBackgroundColor:crossColor]; 
  [self insertLayerWithFrame:CGRectMake(leftWith + lightWidth - crossLineWidth, topHeight, crossLineWidth, crossLineHeight) withBackgroundColor:crossColor]; 
   
  [self insertLayerWithFrame:CGRectMake(leftWith, topHeight + lightHeight - crossLineHeight, crossLineWidth, crossLineHeight) withBackgroundColor:crossColor]; 
  [self insertLayerWithFrame:CGRectMake(leftWith, topHeight + lightHeight - crossLineWidth, crossLineHeight, crossLineWidth) withBackgroundColor:crossColor]; 
   
  [self insertLayerWithFrame:CGRectMake(leftWith + lightWidth - crossLineHeight, topHeight + lightHeight - crossLineWidth, crossLineHeight, crossLineWidth) withBackgroundColor:crossColor]; 
  [self insertLayerWithFrame:CGRectMake(leftWith + lightWidth - crossLineWidth, topHeight + lightHeight - crossLineHeight, crossLineWidth, crossLineHeight) withBackgroundColor:crossColor]; 
} 
 
-(void)initScanCode { 
  @autoreleasepool { 
    _captureDevice = [ AVCaptureDevice defaultDeviceWithMediaType : AVMediaTypeVideo]; 
    _captureInput = [ AVCaptureDeviceInput deviceInputWithDevice : _captureDevice error : nil ]; 
    _captureOutput = [[ AVCaptureMetadataOutput alloc ] init ]; 
    [_captureOutput setMetadataObjectsDelegate : self queue : dispatch_get_main_queue ()]; 
    if (_isRectScan) { 
      CGRect screenRect = [UIScreen mainScreen].bounds; 
      [ _captureOutput setRectOfInterest : CGRectMake (topHeight / screenRect.size.height, leftWith / screenRect.size.width, lightHeight/screenRect.size.height, lightWidth / screenRect.size.width)]; 
    } 
 
    _captureSession = [[ AVCaptureSession alloc ] init ]; 
    [_captureSession setSessionPreset : AVCaptureSessionPresetHigh ]; 
    if ([_captureSession canAddInput : _captureInput ]) 
    { 
      [_captureSession addInput : _captureInput ]; 
    } 
    if ([_captureSession canAddOutput : _captureOutput ]) 
    { 
      [_captureSession addOutput : _captureOutput ]; 
    } 
    _captureOutput.metadataObjectTypes = @[AVMetadataObjectTypeQRCode ] ; 
     
    _capturePreview =[ AVCaptureVideoPreviewLayer layerWithSession :_captureSession ]; 
    _capturePreview.videoGravity = AVLayerVideoGravityResizeAspectFill ; 
    _capturePreview.frame = self.view.layer.bounds ; 
    [self.view.layer insertSublayer : _capturePreview atIndex : 0 ]; 
    [_captureSession startRunning ]; 
  } 
} 
 
- ( void )captureOutput:( AVCaptureOutput *)captureOutput didOutputMetadataObjects:( NSArray *)metadataObjects fromConnection:( AVCaptureConnection *)connection 
{ 
  if (metadataObjects != nil && [metadataObjects count] > 0) { 
    AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0]; 
    NSString *scanCodeResult; 
    if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]) { 
      [self stopScanCode]; 
      scanCodeResult = metadataObj.stringValue; 
      //回调信息 
      if (_delegate && [_delegate respondsToSelector:@selector(scanCodeResultByViewController:withScanCodeResult:)]) { 
        [_delegate scanCodeResultByViewController:self withScanCodeResult:scanCodeResult]; 
        [self.navigationController popViewControllerAnimated:YES]; 
      } 
    } else { 
      NSLog(@"扫描信息错误！"); 
    } 
  } 
} 
 
- (void)systemFlashLight 
{ 
#if !TARGET_IPHONE_SIMULATOR 
  if([_captureDevice hasTorch] && [self.captureDevice hasFlash]) 
  { 
    [_captureSession beginConfiguration]; 
    [_captureDevice lockForConfiguration:nil]; 
    if(_captureDevice.torchMode == AVCaptureTorchModeOff) 
    { 
      _flashLightBtn.selected = YES; 
      [_captureDevice setTorchMode:AVCaptureTorchModeOn]; 
      [_captureDevice setFlashMode:AVCaptureFlashModeOn]; 
    } 
    else { 
      _flashLightBtn.selected = NO; 
      [_captureDevice setTorchMode:AVCaptureTorchModeOff]; 
      [_captureDevice setFlashMode:AVCaptureFlashModeOff]; 
    } 
    [_captureDevice unlockForConfiguration]; 
    [_captureSession commitConfiguration]; 
  } 
#else 
  [CommonUtil showAlert:G_ALERTTITLE withMessage:@"虚拟设备不能运行摄像头！"]; 
#endif 
} 
 
-(void)stopScanCode { 
  [_captureSession stopRunning]; 
  _captureSession = nil; 
  _captureDevice = nil; 
  _captureInput = nil; 
  _captureOutput = nil; 
  [_capturePreview removeFromSuperlayer]; 
} 
 
- (void)didReceiveMemoryWarning { 
  [super didReceiveMemoryWarning]; 
} 
 
@end