iOS 原生二维码扫描

iOS自带的条码扫描比第三方库要快一些

首先要导入#import

//二维码生成的会话
@property (nonatomic, strong) AVCaptureSession *mySession;

//二维码生成的图层
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *myPreviewLayer;


@end

@implementation ScanningViewController

- (void)viewDidLoad {
    [super viewDidLoad];

    self.title = @"扫描";


    //扫描二维码
    [self readQRcode];

}

-(void)viewDidAppear:(BOOL)animated{

    [self.mySession startRunning];

}


#pragma mark - 扫描条码
-(void)readQRcode
{

    //1、获取摄像头设备
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];


    //2、设置输入
    NSError *error = nil;
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];


    if (error) {
        NSLog(@"没有摄像头：%@", error.localizedDescription);
        return;
    }


    //3、设置输出（metadata 元数据）
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

    //4、创建拍摄会话
    AVCaptureSession *session = [[AVCaptureSession alloc] init];

    //添加session的输入和输出
    [session addInput:input];
    [session addOutput:output];

    // 4.1 设置输出的格式
    // 提示：一定要先设置会话的输出为output之后，再指定输出的元数据类型！
    [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode, AVMetadataObjectTypeCode39Code, AVMetadataObjectTypeCode128Code, AVMetadataObjectTypeCode39Mod43Code, AVMetadataObjectTypeEAN13Code,  AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode93Code]];


    // 5. 设置预览图层（用来让用户能够看到扫描情况）
    AVCaptureVideoPreviewLayer *preview = [AVCaptureVideoPreviewLayer layerWithSession:session];

    // 5.1 设置preview图层的属性
    [preview setVideoGravity:AVLayerVideoGravityResizeAspectFill];

    // 5.2 设置preview图层的大小
    [preview setFrame:self.view.bounds];

    // 5.3 将图层添加到视图的图层
    [self.view.layer insertSublayer:preview atIndex:0];


    // 6. 启动会话
    [session startRunning];


    self.myPreviewLayer = preview;
    self.mySession = session;


}

#pragma  mark - 输出代理方法
// 此方法是在识别到QRCode，并且完成转换
// QRCode的内容越大，转换需要的时间就越长
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{


    // 会频繁的扫描，调用代理方法
    // 1. 如果扫描完成，停止会话
    [self.mySession stopRunning];


    // 2. 删除预览图层
//    [self.myPreviewLayer removeFromSuperlayer];

    NSLog(@"%@", metadataObjects);


    // 3. 设置界面显示扫描结果
    if (metadataObjects.count > 0) {

        AVMetadataMachineReadableCodeObject *obj = metadataObjects[0];

        ScanResultViewController *scanResultVC = [[ScanResultViewController alloc]init];

        //将扫描到的文字显示
        scanResultVC.textStr = obj.stringValue;

        //跳转页面
        [self.navigationController pushViewController:scanResultVC animated:YES];

    }

}