iOS自带扫码实现以及扫码类型

//
//  SYTCodeScanerViewController.m
//  SYTCodeScan
//
//  Created by iMac on 15/5/6.
//  Copyright (c) 2015年 S.F. All rights reserved.
//

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

@interface SYTCodeScanerViewController ()<AVCaptureMetadataOutputObjectsDelegate, UIImagePickerControllerDelegate, UINavigationControllerDelegate>

@property (nonatomic ,strong) AVCaptureSession *captureSession;                 //捕捉会话
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *videoPreviewLayer;    //预览图层layer
@property (strong, nonatomic) UIView *boxView;                                  //扫描识别框

@property (weak, nonatomic) IBOutlet UILabel *resoultLab;                       //结果显示Lab

@property (weak, nonatomic) IBOutlet UIButton *scanImageButton;

@property (nonatomic, strong) UIImagePickerController *imagePickerController;

@end

@implementation SYTCodeScanerViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    _captureSession = nil;
    
    [self startScan];
    
}

- (void)startScan
{
    //初始化设备(摄像头)
    NSError *error = nil;
    AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
    
    //创建输入流
    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];
    if (error)
    {
        NSLog(@"没有摄像头:%@", error.localizedDescription);
        return;
    }
    
    
    //创建输出流
    AVCaptureMetadataOutput *output = [[AVCaptureMetadataOutput alloc] init];
    
    //实例化捕捉会话并添加输入,输出流
    _captureSession = [[AVCaptureSession alloc] init];
    //高质量采集率
    [_captureSession setSessionPreset:AVCaptureSessionPresetHigh];
    
    [_captureSession addInput:input];
    [_captureSession addOutput:output];
    
    //设置输出的代理,在主线程里刷新
    [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];   //用串行队列新线程结果在UI上显示较慢
    
    //扫码类型
    [output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode,         //二维码
                                     AVMetadataObjectTypeCode39Code,     //条形码   韵达和申通
                                     AVMetadataObjectTypeCode128Code,    //商品条码  顺丰用的
                                     AVMetadataObjectTypeCode39Mod43Code,
                                     AVMetadataObjectTypeEAN13Code,
                                     AVMetadataObjectTypeEAN8Code,
                                     AVMetadataObjectTypeCode93Code, //条形码,星号来表示起始符及终止符,如邮政EMS单上的条码
                                     AVMetadataObjectTypeUPCECode]];
    
    _videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:_captureSession];
    
    [_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    
    //添加预览图层
    _videoPreviewLayer.frame = self.view.frame;
    [self.view.layer addSublayer:_videoPreviewLayer];
    [self.view bringSubviewToFront:self.view.subviews[0]];

    
    //扫描框
    
    _boxView = [[UIView alloc] initWithFrame:CGRectMake(60, 100, 200, 200)];
    _boxView.layer.borderColor = [UIColor greenColor].CGColor;
    _boxView.layer.borderWidth = 1.0f;
    [self.view addSubview:_boxView];
    
    //扫描识别范围
    output.rectOfInterest = CGRectMake(100 / self.view.bounds.size.height,
                                       60  / self.view.bounds.size.width,
                                       200 / self.view.bounds.size.height,
                                       200 / self.view.bounds.size.width);
    
    //开始扫描
    [_captureSession startRunning];
    
    
}

#pragma mark - 扫描结果代理方法
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    [_captureSession stopRunning];
//    [_videoPreviewLayer removeFromSuperlayer];
    
    if (metadataObjects.count > 0) {
        
        AVMetadataMachineReadableCodeObject *obj = metadataObjects[0];
        
        _resoultLab.text = obj.stringValue;
        
        NSLog(@"扫码扫描结果,obj.stringValue == %@", obj.stringValue);
    }
    
}


#pragma mark 选择照片

#pragma -mark - UIImagePickerViewControllerDelegate
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    
    NSLog(@"info == %@", info);
    [self.imagePickerController dismissViewControllerAnimated:YES completion:nil];
    
    UIImage *image = [info objectForKey:@"UIImagePickerControllerOriginalImage"];
    
    
}


- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
    [self.imagePickerController dismissViewControllerAnimated:YES completion:nil];

}

- (IBAction)photoPickBtn:(UIButton *)sender {
    
    if (!_imagePickerController) {
        
        _imagePickerController = [[UIImagePickerController alloc] init];
        _imagePickerController.delegate =self;
        _imagePickerController.SourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    }
    
    [self presentViewController:self.imagePickerController animated:YES completion:nil];
}
@end

首先，AVCaptureMetadataOutput类中有一个这样的属性(在IOS7.0之后可用)：

@property(nonatomic) CGRect rectOfInterest;

　　这个属性大致意思就是告诉系统它需要注意的区域，大部分APP的扫码UI中都会有一个框，提醒你将条形码放入那个区域，这个属性的作用就在这里，它可以设置一个范围，只处理在这个范围内捕获到的图像的信息。如此一来，可想而知，我们代码的效率又会得到很大的提高，在使用这个属性的时候。需要几点注意：

1、这个CGRect参数和普通的Rect范围不太一样，它的四个值的范围都是0-1，表示比例。

2、经过测试发现，这个参数里面的x对应的恰恰是距离左上角的垂直距离，y对应的是距离左上角的水平距离。

3、宽度和高度设置的情况也是类似。

3、举个例子如果我们想让扫描的处理区域是屏幕的下半部分，我们这样设置

output.rectOfInterest=CGRectMake(0.5,0,0.5, 1);

。