iOS开发 - 系统自带框架实现扫一扫功能-编程知识

iOS开发 - 系统自带框架实现扫一扫功能

iOS 扫一扫

利用系统自带框架实现扫一扫功能

一项目配置

扫一扫功能相机和相册权限，在info.plist中设置询问用户是否允许访问的权限。

info.plist加入NSCameraUsageDescription、NSPhotoLibraryUsageDescription、NSPhotoLibraryAddUsageDescription

<key>NSCameraUsageDescription</key><string>开启相机权限，活动扫一扫更快捷</string><key>NSPhotoLibraryAddUsageDescription</key><string>添加照片需要您的同意</string><key>NSPhotoLibraryUsageDescription</key><string>开启照片权限，美照当然要人赞！</string>

二扫一扫权限判断

当每次进入扫一扫页面时，需要判断是否开启了权限


/** 校验是否有相机权限 */
- (void)checkCameraAuthorizationStatus:(void(^)(BOOL granted))permissionGranted
{AVAuthorizationStatus videoAuthStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];switch (videoAuthStatus) {// 已授权case AVAuthorizationStatusAuthorized:{permissionGranted(YES);}break;// 未询问用户是否授权case AVAuthorizationStatusNotDetermined:{// 提示用户授权[AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {permissionGranted(granted);}];}break;// 用户拒绝授权或权限受限case AVAuthorizationStatusRestricted:case AVAuthorizationStatusDenied:{UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"请在”设置-隐私-相机”选项中，允许访问你的相机" message:nil delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];[alert show];permissionGranted(NO);}break;default:break;}
}

三需要用到AVCaptureDevice、AVCaptureDeviceInput、AVCaptureMetadataOutput、AVCaptureSession、AVCaptureVideoPreviewLayer

AVCaptureDevice：捕获设备，通常是前置摄像头，后置摄像头，麦克风（音频输入）
AVCaptureDeviceInput：AVCaptureDeviceInput 代表输入设备，使用AVCaptureDevice 来初始化
AVCaptureMetadataOutput：输出
AVCaptureSession：session 把输入输出结合在一起，并开始启动捕获设备（摄像头）
AVCaptureVideoPreviewLayer：图像预览层，实时显示捕获的图像

设置相机


/**设置相机
*/
- (void)setupCamera {self.avDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];self.avInput = [AVCaptureDeviceInput deviceInputWithDevice:self.avDevice error:nil];self.avOutput = [[AVCaptureMetadataOutput alloc]init];[self.avOutput setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];self.avSession = [[AVCaptureSession alloc]init];[self.avSession setSessionPreset:AVCaptureSessionPresetHigh];if ([self.avSession canAddInput:self.avInput]){[self.avSession addInput:self.avInput];}if ([self.avSession canAddOutput:self.avOutput]){[self.avSession addOutput:self.avOutput];}// 二维码类型 AVMetadataObjectTypeQRCodeif ([self.avOutput.availableMetadataObjectTypes containsObject:AVMetadataObjectTypeQRCode]){self.avOutput.metadataObjectTypes = [NSArray arrayWithObject:AVMetadataObjectTypeQRCode];// AVMetadataObjectTypeAztecCode 条形码} else{return ;}[self.avSession startRunning];//开始扫描
}

返回预览layer

/**显示的预览layer@return AVCaptureVideoPreviewLayer*/
- (AVCaptureVideoPreviewLayer *)showPeviewLayer {self.avPreviewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.avSession];self.avPreviewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;return self.avPreviewLayer;
}

开始扫描与结束扫描

/**开始扫描*/
- (void)startRunning {[self.avSession startRunning];
}/**结束扫描*/
- (void)stopRunning {[self.avSession stopRunning];
}

输出扫描结果AVCaptureMetadataOutputObjectsDelegate


#pragma mark - AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:
(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{if ([metadataObjects count] > 0){AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex:0];NSString *result = metadataObject.stringValue;//扫描出来的字符串NSLog(@"result:%@",result);UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"显示扫描结果" message:result delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil];[alert show];[self.avSession stopRunning];//停止扫描}
}

使用

	self.scanConfig = [[INQrScanConfig alloc] init];[self.scanConfig setupCamera];AVCaptureVideoPreviewLayer *previewLayer = [self.scanConfig showPeviewLayer];previewLayer.frame = self.layer.bounds;[self.layer insertSublayer:previewLayer atIndex:0];[self.scanConfig startRunning];

使用

//你要设置的矩形快的frame  为  x1, y1, w1, h1.//那么你的 rectOfInterest 应该设置为   (y1/h, x1/w, h1/h, w1/w)CGFloat size = 260.0;CGRect rect = CGRectMake((KAiSysScreenWidth - size)/2, (KAiSysScreenHeight - size)/2, size, size);// 使用 (y1/h, x1/w, h1/h, w1/w)self.avOutput.rectOfInterest = CGRectMake(rect.origin.y/KAiSysScreenHeight, rect.origin.x/KAiSysScreenWidth, size/KAiSysScreenHeight, size/KAiSysScreenWidth);

结果如图：
在这里插入图片描述