iOS two dimensional code generation and scanning code detailed explanation and example code

iOS 2-Dimensional Code Generation and Code Scanning

Nowadays, more and more applications join the business related to 2D code. In iOS development market, many developers are using the third-party controls for scanning code and generating 2D code. Personally, I think that the recognition degree of such third-party controls is not high. Recently, I just sorted out the new framework and studied it for 1 time. The specific code is as follows

Generate 2-D code code

/** 
 * @author  Half    Satiety , 15-12-18 
 * 
 * @brief  Generate 2 Dimension code picture  
 * 
 * @param code   Generate 2 Dimension code picture content  
 * @param width 2 Dimension code picture width  
 * @param height 2 Dimension code picture height  
 * 
 * @return  Return UIImage Object  
 */ 
- (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]; 
} 

Scan 2D code

#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]; // Whether listening triggers home Key suspender . 
  [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(didBecomeActiveNotification) name:UIApplicationDidBecomeActiveNotification object:nil]; // Monitor whether to re-enter the program . 
} 
 
-(void)viewWillDisappear:(BOOL)animated { 
   [self stopScanCode]; 
  [super viewWillDisappear:animated]; 
} 
 
- (void)willResignActiveNotification { 
  _flashLightBtn.selected = NO; 
} 
- (void)didBecomeActiveNotification { 
 
} 
// Load the controls on the interface, such as adding flash buttons and so on  
- (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]; 
  // Set up proxy  
  [UIView setAnimationDelegate:self]; 
  // Set the event called when the animation is finished  
  [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]; 
  } 
} 
// Initialization layer Layer to draw translucent areas  
-(void) initLayer { 
  // Common parameter  
  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; 
      // Callback information  
      if (_delegate && [_delegate respondsToSelector:@selector(scanCodeResultByViewController:withScanCodeResult:)]) { 
        [_delegate scanCodeResultByViewController:self withScanCodeResult:scanCodeResult]; 
        [self.navigationController popViewControllerAnimated:YES]; 
      } 
    } else { 
      NSLog(@" Error scanning information! "); 
    } 
  } 
} 
 
- (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:@" Virtual device can't run camera! "]; 
#endif 
} 
 
-(void)stopScanCode { 
  [_captureSession stopRunning]; 
  _captureSession = nil; 
  _captureDevice = nil; 
  _captureInput = nil; 
  _captureOutput = nil; 
  [_capturePreview removeFromSuperlayer]; 
} 
 
- (void)didReceiveMemoryWarning { 
  [super didReceiveMemoryWarning]; 
} 
 
@end 

Thank you for reading, hope to help everyone, thank you for your support to this site!