iOS开发--二维码的扫描

一.需要包含头文件

#import <AVFoundation/AVFoundation.h>

二.通过设置<AVCaptureMetadataOutputObjectsDelegate>代理可以监听扫描到的二维码中的信息

三.具体代码

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>

@interface ViewController () <AVCaptureMetadataOutputObjectsDelegate>

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    // 1.创建捕捉会话
    AVCaptureSession *session = [[AVCaptureSession alloc] init];
    
    // 2.设置输入设备
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    AVCaptureDeviceInput *inputDevice = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
    [session addInput:inputDevice];
    
    // 3.设置输入方式
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    [session addOutput:output];
    [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];
    
    // 4.添加一个显示的layer
    AVCaptureVideoPreviewLayer *layer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
    layer.frame = self.view.bounds;
    [self.view.layer addSublayer:layer];
    
    // 5.开始扫描
    [session startRunning];
}

#pragma mark - 获取扫描结果
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    if (metadataObjects.count > 0) {
        AVMetadataMachineReadableCodeObject *object = [metadataObjects lastObject];
        NSLog(@"%@", object.stringValue);
    }
}

@end