废话不多直接上代码看注释，大家的智慧结晶。

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1.声明头文件

<p><code>

#import <Foundation/Foundation.h>

#import <UIKit/UIKit.h>
#import <AudioToolbox/AudioToolbox.h>

typedef void (^YYScanSuccessBlock)(NSString *scanResult);
@interface YYScanHelper : NSObject

//第一步：创建声明单例方法
+ (instancetype)manager;

@property (nonatomic, strong) UIView *scanView;

@property (nonatomic, copy) YYScanSuccessBlock scanBlock;

//开始扫描

- (void)startRunning;

//停止扫描

- (void)stopRunning;

//显示扫描扫描结果的窗口

- (void)showLayer:(UIView *)superView;

//设置扫描窗口的范围

- (void)setScanningRect:(CGRect)scanRect scanView:(UIView *)scanView;

@end
</code></p>

---

2.代码实现

<p><code>
#import "YYScanHelper.h"

#import <AVFoundation/AVFoundation.h>

@interface YYScanHelper()<AVCaptureMetadataOutputObjectsDelegate>
{

//声明扫描需要的系统类
AVCaptureSession *_session;
AVCaptureVideoPreviewLayer *_layer;
AVCaptureMetadataOutput *_output;
AVCaptureDeviceInput *_input;
UIView *_superView;

}

@end

@implementation YYScanHelper

+ (instancetype)manager

{
//封装非标准单利
static YYScanHelper *singleton = nil;

static dispatch_once_t onceToken;

dispatch_once(&onceToken, ^{

    singleton = [[YYScanHelper alloc] init];
    
});

return singleton;

}

- (id)init
{

self = [super init];

if (self) {
    //初始化链接对象
    _session = [[AVCaptureSession alloc]init];
    
    //高质量采集
    [_session setSessionPreset:AVCaptureSessionPresetHigh];
    
    //避免模拟器运行崩溃
    if (!TARGET_IPHONE_SIMULATOR) {
        //获取摄像设备
        AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
        
        //创建输入流
        _input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];
        
        //添加到链接对象
        [_session addInput:_input];
        
        //创建输出流
        _output = [[AVCaptureMetadataOutput alloc]init];
        
        //添加到链接对象
        [_session addOutput:_output];
        
        //设置代理  在主线程里刷新
        [_output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
        
        //设置扫码支持的编码格式（如下设置条形码和二维码兼容）
        _output.metadataObjectTypes = @[AVMetadataObjectTypeQRCode,
                                        AVMetadataObjectTypeEAN8Code,
                                        AVMetadataObjectTypeEAN13Code,
                                        AVMetadataObjectTypeCode128Code];
        
        
    }
    
    _layer = [AVCaptureVideoPreviewLayer layerWithSession:_session];
    _layer.videoGravity = AVLayerVideoGravityResizeAspectFill;
    
}

return self;

}

- (void)startRunning {

    //开始捕获
    [_session startRunning];

}

• (void)stopRunning {

     //停止捕获 
  

  [_session stopRunning];

}

pragma mark - AVCaptureMetadataOutputObjects Delegate

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{

if (metadataObjects.count > 0) {
    //扫码完成
    [_session stopRunning];
    //播放系统声音（ID可选）
    AudioServicesPlaySystemSound(1200);
    AVMetadataMachineReadableCodeObject *metadataObject = [metadataObjects objectAtIndex:0];
    
    if (self.scanBlock) {
        
        self.scanBlock(metadataObject.stringValue);
        
    }
    
    //输出扫描字符串
    NSLog(@"输出扫描字符串为：%@",metadataObject.stringValue);
    
}

}

/**
* @param 设置扫描范围区域 CGRectMake （y的起点/屏幕的高，x的起点/屏幕的款,扫描的区域的高/屏幕的高，扫描的区域的宽/屏幕的宽）
*

* @param scanRect 扫描范围

* @param scanView 扫描框

*/

- (void)setScanningRect:(CGRect)scanRect scanView:(UIView *)scanView
{

    CGFloat x,y,width,height;

    x = scanRect.origin.y / _layer.frame.size.height;

    y = scanRect.origin.x / _layer.frame.size.width;

    width = scanRect.size.height / _layer.frame.size.height;

    height = scanRect.size.width / _layer.frame.size.width;

    _output.rectOfInterest = CGRectMake(x, y, width, height);

    self.scanView = scanView;

    if (self.scanView) {
    
            self.scanView.frame = scanRect;
    
            if (_superView) {
        
                    [_superView addSubview:self.scanView];
        
            }
    }

}

/**

* @param显示图层

*

* @param superView 需要在哪个View显示

*/

- (void)showLayer:(UIView *)superView
{

    _superView = superView;

    _layer.frame = superView.layer.frame;

    [superView.layer insertSublayer:_layer atIndex:0];

}

@end
</code></p>

---

3.使用方法

<p><code>
[[YYScanHelper manager] showLayer:self.view];

[[YYScanHelper manager] setScanningRect:self.scanRect scanView:scanRectView];

[[YYScanHelper manager] setScanBlock:^(NSString *scanResult){

    NSLog(@"打印扫描传值结果%@",scanResult);
    

[[YYScanHelper manager] startRunning];

</code></p>