iOS扫描二维码

引用#import <AVFoundation/AVFoundation.h>系统库

判断权限

//判断权限
    [AVCaptureDevice requestAccessForMediaType:AVMediaTypeVideo completionHandler:^(BOOL granted) {
        dispatch_async(dispatch_get_main_queue(), ^{
            if (granted) {
                [self loadScanView];
            } else {
                NSString *title = @"请在iPhone的”设置-隐私-相机“选项中，允许App访问你的相机";
                UIAlertController *ctrl = [UIAlertController alertControllerWithTitle:title message:nil preferredStyle:UIAlertControllerStyleAlert];
                UIAlertAction *action = [UIAlertAction actionWithTitle:@"好" style:UIAlertActionStyleDefault handler:nil];
                [ctrl addAction:action];
            }
        });
    }];

初始化各对象

@property (nonatomic, strong) AVCaptureSession *session;

- (void)loadScanView {
    //获取摄像设备
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    //创建输入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
    //创建输出流
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc]init];
    //设置代理 在主线程里刷新
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    //初始化链接对象
    self.session = [[AVCaptureSession alloc]init];
    //高质量采集率
    [self.session setSessionPreset:AVCaptureSessionPresetHigh];
    
    //添加输入输出
    [self.session addInput:input];
    [self.session addOutput:output];
    //设置扫码支持的编码格式NSArray<AVMetadataObjectType>*
    output.metadataObjectTypes=@[AVMetadataObjectTypeQRCode];

    //设置相机的取景器
    AVCaptureVideoPreviewLayer *layer = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
    //相机内容显示模式
    layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    layer.frame = self.view.layer.bounds;
    [self.view.layer insertSublayer:layer atIndex:0];
    
    //启用session
    [self.session startRunning];
}

扫描结果

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection {
    [self.session stopRunning];//停止会话
    [self.preview removeFromSuperlayer];//移除取景器
    
    if (metadataObjects.count > 0) {
        AVMetadataMachineReadableCodeObject *obj = metadataObjects[0];
        //扫描结果
        NSString *result = obj.stringValue;
        //后续处理...
    }
}

开启/关闭闪光灯

if (_isOnlight) { //打开闪光灯
        AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        NSError *error = nil;
        if ([captureDevice hasTorch]) {
            BOOL locked = [captureDevice lockForConfiguration:&error];
            if (locked) {
                captureDevice.torchMode = AVCaptureTorchModeOn;
                [captureDevice unlockForConfiguration];
            }
        }
    }else{//关闭闪光灯
        AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        if ([captureDevice hasTorch]) {
            [captureDevice lockForConfiguration:nil];
            [captureDevice setTorchMode: AVCaptureTorchModeOff];
            [captureDevice unlockForConfiguration];
        }
    }