IOS原聲二維碼條形碼掃描實現
阿新 • • 發佈：2019-01-02
本文講述如何用系統自帶的東東實現二維碼掃描的功能:點選當前頁面的某個按鈕，建立掃描VIEW。細心的小夥伴可以發現 title被改變了，返回按鈕被隱藏了。這個程式碼自己寫就行了，與本文關係不大。。。綠色的線會上下跑，不要擔心:D
實現效果如下：
1.在工程中新增框架AVFoundation.framework
2.宣告代理：AVCaptureMetadataOutputObjectsDelegate 。 define 幾個東東用來畫框、畫線：
#define SCANVIEW_EdgeTop 40.0 #define SCANVIEW_EdgeLeft 50.0 #define TINTCOLOR_ALPHA 0.2 //淺色透明度 #define DARKCOLOR_ALPHA 0.5 //深色透明度 #define VIEW_WIDTH [UIScreen mainScreen].bounds.size.width #define VIEW_HEIGHT [UIScreen mainScreen].bounds.size.height
3.宣告以下屬性：
AVCaptureSession * session;//輸入輸出的中間橋樑 UIView *AVCapView;//此 view 用來放置掃描框、取消按鈕、說明 label UIView *_QrCodeline;//上下移動綠色的線條NSTimer *_timer;
4.在某個方法中（我是點選掃描按鈕）建立掃描介面，開始掃描：
//建立一個 view 來放置掃描區域、說明 label、取消按鈕 UIView *tempView = [[UIView alloc]initWithFrame:CGRectMake(0, 0, 320, [UIScreen mainScreen].bounds.size.height )]; AVCapView = tempView; AVCapView.backgroundColor = [UIColor colorWithRed:54.f/255 green:53.f/255 blue:58.f/255 alpha:1]; UIButton *cancelBtn = [[UIButton alloc]initWithFrame:CGRectMake(15, [UIScreen mainScreen].bounds.size.height - 100, 50, 25)]; UILabel *label = [[UILabel alloc]initWithFrame:CGRectMake(15, 268, 290, 60)]; label.numberOfLines = 0; label.text = @"小提示：將條形碼或二維碼對準上方區域中心即可"; label.textColor = [UIColor grayColor]; [cancelBtn setTitle:@"取消" forState: UIControlStateNormal]; [cancelBtn setTitleColor:[UIColor grayColor] forState:UIControlStateNormal]; [cancelBtn addTarget:self action:@selector(touchAVCancelBtn) forControlEvents:UIControlEventTouchUpInside]; [AVCapView addSubview:label]; [AVCapView addSubview:cancelBtn]; [self.view addSubview:AVCapView]; //畫上邊框 UIView *topView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop, VIEW_WIDTH- 2 * SCANVIEW_EdgeLeft, 1)]; topView.backgroundColor = [UIColor whiteColor]; [AVCapView addSubview:topView]; //畫左邊框 UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop , 1,VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft )]; leftView.backgroundColor = [UIColor whiteColor]; [AVCapView addSubview:leftView]; //畫右邊框 UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft + VIEW_WIDTH- 2 * SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop , 1,VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft + 1)]; rightView.backgroundColor = [UIColor whiteColor]; [AVCapView addSubview:rightView]; //畫下邊框 UIView *downView = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop + VIEW_WIDTH- 2 * SCANVIEW_EdgeLeft,VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft ,1 )]; downView.backgroundColor = [UIColor whiteColor]; [AVCapView addSubview:downView]; //畫中間的基準線 _QrCodeline = [[UIView alloc] initWithFrame:CGRectMake(SCANVIEW_EdgeLeft + 1, SCANVIEW_EdgeTop, VIEW_WIDTH- 2 * SCANVIEW_EdgeLeft - 1, 2)]; _QrCodeline.backgroundColor = [UIColor greenColor]; [AVCapView addSubview:_QrCodeline]; // 先讓基準線運動一次，避免定時器的時差 [UIView animateWithDuration:1.2 animations:^{ _QrCodeline.frame = CGRectMake(SCANVIEW_EdgeLeft + 1, VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft + SCANVIEW_EdgeTop , VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft - 1, 2); }]; [self performSelector:@selector(createTimer) withObject:nil afterDelay:0.4]; AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; //建立輸入流 AVCaptureDeviceInput * input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil]; //建立輸出流 AVCaptureMetadataOutput * output = [[AVCaptureMetadataOutput alloc]init]; //設定代理 在主執行緒裡重新整理 [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()]; //初始化連結物件 session = [[AVCaptureSession alloc]init]; //高質量採集率 [session setSessionPreset:AVCaptureSessionPresetHigh]; [session addInput:input]; [session addOutput:output]; //設定掃碼支援的編碼格式(如下設定條形碼和二維碼相容) output.metadataObjectTypes=@[AVMetadataObjectTypeQRCode,AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code]; AVCaptureVideoPreviewLayer * layer = [AVCaptureVideoPreviewLayer layerWithSession:session]; layer.videoGravity=AVLayerVideoGravityResizeAspectFill; layer.frame = CGRectMake(SCANVIEW_EdgeLeft, SCANVIEW_EdgeTop, VIEW_WIDTH- 2 * SCANVIEW_EdgeLeft, 220); [AVCapView.layer insertSublayer:layer atIndex:0]; //開始捕獲 [session startRunning];
5.實現定時器、還有基準線的滾動方法
- (void)createTimer { _timer=[NSTimer scheduledTimerWithTimeInterval:1.1 target:self selector:@selector(moveUpAndDownLine) userInfo:nil repeats:YES]; } - (void)stopTimer { if ([_timer isValid] == YES) { [_timer invalidate]; _timer = nil; } } // 滾來滾去 :D :D :D - (void)moveUpAndDownLine { CGFloat YY = _QrCodeline.frame.origin.y; if (YY != VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft + SCANVIEW_EdgeTop ) { [UIView animateWithDuration:1.2 animations:^{ _QrCodeline.frame = CGRectMake(SCANVIEW_EdgeLeft + 1, VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft + SCANVIEW_EdgeTop , VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft - 1,2); }]; }else { [UIView animateWithDuration:1.2 animations:^{ _QrCodeline.frame = CGRectMake(SCANVIEW_EdgeLeft + 1, SCANVIEW_EdgeTop, VIEW_WIDTH - 2 * SCANVIEW_EdgeLeft - 1,2); }]; } }
6.掃描成功後，想幹嘛幹嘛，就在這個代理方法裡面實現就行了
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{ if (metadataObjects.count>0) { //[session stopRunning]; AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex : 0 ]; //輸出掃描字串 NSLog(@"%@",metadataObject.stringValue); [session stopRunning]; [self stopTimer]; [AVCapView removeFromSuperview]; ..... } }
7.如果使用者不想掃描了，點選取消按鈕：
- (void)touchAVCancelBtn{ [session stopRunning];//攝像也要停止 [self stopTimer];//定時器要停止 [AVCapView removeFromSuperview];//剛剛建立的 view 要移除 ... }