iOS原生二维码扫描

7.0以后出来原生的二维码扫描之前一直使用ZBar和ZXing，而苹果又要求现在提交的应用必须支持64位编程，在网上搜了了一下ZBar的64位编程，虽然有解决64位编程办法但本人一直没有解决好，就打算放弃使用ZBar，开始使用原生的，查阅了一些相关文章，感觉有点乱，我就把自己写的代码整理了一下贴出来，希望对需要的人有所帮助

1.首先在工程里添加AVFoundation.framework框架

2.在.m文件中导入文件

#import <AVFoundation/AVFoundation.h>

3.添加两个属性，代理是后添加的

@interface ScanViewController ()<AVCaptureMetadataOutputObjectsDelegate>

@property (nonatomic,strong)AVCaptureSession *captureSession;

@property (nonatomic,strong)AVCaptureVideoPreviewLayer *preView;

@end

4.扫描代码

    NSError *error;
    //1.初始化捕捉设备（AVCaptureDevice），类型为AVMediaTypeVideo
    AVCaptureDevice *caputreDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    
    //2.用captureDevice创建输入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:caputreDevice error:&error];
    
    //3.创建媒体数据输出流
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
    //3.1设置代理，然后添加代理协议
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    
    
    //4.实例化捕捉会话
    self.captureSession = [[AVCaptureSession alloc] init];
    //实现高质量的输出和摄像，默认值为AVCaptureSessionPresetHigh，可以不写
    self.captureSession.sessionPreset = AVCaptureSessionPresetHigh;
    
    //4.1将输入流添加到会话
    if([self.captureSession canAddInput:input]){
        [self.captureSession addInput:input];
    }
    //4.2将输出流添加到会话中
    if([self.captureSession canAddOutput:output]){
        [self.captureSession addOutput:output];
    }
    
    //5设置输出媒体数据类型为QRCode
    output.metadataObjectTypes = @[AVMetadataObjectTypeQRCode];
    
    //6.实例化预览图层
    self.preView = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
    //6.1设置填充方式
    self.preView.videoGravity = AVLayerVideoGravityResizeAspectFill;
    self.preView.frame = self.view.layer.bounds;
    [self.view.layer insertSublayer:self.preView atIndex:0];
    
    //7.添加扫描框
    UIView *boxView = [[UIView alloc] initWithFrame:CGRectMake((320-200)/2.0,(568-64-200)/2.0+64,200,200)];
    boxView.backgroundColor = [UIColor clearColor];
    boxView.layer.borderColor = [UIColor greenColor].CGColor;
    boxView.layer.borderWidth = 1.0f;
    [self.view addSubview:boxView];
    
    //8.设置扫描区域
    output.rectOfInterest = CGRectMake(boxView.top/568.0, boxView.left/320.0, boxView.height/568.0, boxView.width/320.0);
    
    //9.1设置扫描区域顶部透明图层
    UIView *topView = [[UIView alloc] initWithFrame:CGRectMake(0, 64, 320, boxView.top-64)];
    topView.backgroundColor = [UIColor blackColor];
    topView.alpha = 0.4;
    [self.view addSubview:topView];
    //9.2设置扫描区域底部透明图层
    UIView *bottomView = [[UIView alloc] initWithFrame:CGRectMake(0, boxView.bottom, 320, 568-boxView.bottom)];
    bottomView.backgroundColor = [UIColor blackColor];
    bottomView.alpha = 0.4;
    [self.view addSubview:bottomView];
    //9.3设置扫描区域左部透明图层
    UIView *leftView = [[UIView alloc] initWithFrame:CGRectMake(0, boxView.top, boxView.left, boxView.height)];
    leftView.backgroundColor = [UIColor blackColor];
    leftView.alpha = 0.4;
    [self.view addSubview:leftView];
    //9.4设置扫描区域右部透明图层
    UIView *rightView = [[UIView alloc] initWithFrame:CGRectMake(boxView.right, boxView.top, 320-boxView.right, boxView.height)];
    rightView.backgroundColor = [UIColor blackColor];
    rightView.alpha = 0.4;
    [self.view addSubview:rightView];
    
    //开始扫描
    [self.captureSession startRunning];

5.代理方法内部处理

#pragma mark - AVCaptureMetadataOutputObjectsDelegate
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection {
    
    if(metadataObjects.count > 0){
        //停止扫描
        [self.captureSession stopRunning];
        
        AVMetadataMachineReadableCodeObject *metadataObject = metadataObjects[0];
        //获取扫描结果
        NSString *stringValue = metadataObject.stringValue;
    }
}

到此就可以实现二维码扫描了，速度很快！