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