iOS APP原生二维码使用介绍

在app开发中，经常会遇到二维码扫描的功能。

今天我给大家介绍一下,iOS原生一维码、二维码扫描使用。简单实用

话不多说，直接上单代码

原生二维码扫描使用到<AVFoundation/AVFoundation.h>
在ViewController.m中：

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

#define SCREEN_WIDTH [UIScreen mainScreen].bounds.size.width
#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height
@interface ViewController ()<UITabBarDelegate,AVCaptureMetadataOutputObjectsDelegate,UINavigationControllerDelegate,UIImagePickerControllerDelegate>

@property ( strong , nonatomic ) AVCaptureDevice * device;
@property ( strong , nonatomic ) AVCaptureDeviceInput * input;
@property ( strong , nonatomic ) AVCaptureMetadataOutput * output;
@property ( strong , nonatomic ) AVCaptureSession * session;
@property ( strong , nonatomic ) AVCaptureVideoPreviewLayer * previewLayer;

/*** 专门用于保存描边的图层 ***/
@property (nonatomic,strong) CALayer *containerLayer;

@property(strong,nonatomic)UIView *customContainerView;

@property(strong,nonatomic)UILabel *customLabel;

@property(strong,nonatomic)UILabel *customLab;

@property(strong,nonatomic)UIButton *commodityBtn;

@end

@implementation ViewController

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
self.view.alpha = 1;

self.customContainerView = [[UIView alloc]initWithFrame:CGRectMake(SCREEN_WIDTH/5, SCREEN_HEIGHT/4, SCREEN_WIDTH*3/5, SCREEN_WIDTH*3/5)];
[self.customContainerView.layer setBorderWidth:2.0];
self.customContainerView.layer.borderColor = [UIColor colorWithRed:174/255.0 green:109/255.0 blue:45/255.0 alpha:1].CGColor;

//    self.customContainerView.backgroundColor = [UIColor redColor];
[self.view addSubview:_customContainerView];

self.customLab = [[UILabel alloc]initWithFrame:CGRectMake(SCREEN_WIDTH/5, SCREEN_HEIGHT/4+SCREEN_WIDTH*3/5+10, SCREEN_WIDTH*3/5, 30)];
self.customLab.text = @"将二维码／条形码放入框内，即可自动扫描";
self.customLab.font = [UIFont systemFontOfSize:11.0];
self.customLab.textAlignment = NSTextAlignmentCenter;
self.customLab.textColor = [UIColor whiteColor];

self.customLab.backgroundColor = [UIColor clearColor];
[self.view addSubview:_customLab];

self.customLabel = [[UILabel alloc]init];

self.commodityBtn = [[UIButton alloc]initWithFrame:CGRectMake(SCREEN_WIDTH/2-45, SCREEN_HEIGHT*3/4, 90, 30)];
self.commodityBtn.backgroundColor = [UIColor lightGrayColor];
[self.commodityBtn addTarget:self action:@selector(commodity:) forControlEvents:UIControlEventTouchUpInside];
[self.commodityBtn setTitle:@"直接录入" forState:UIControlStateNormal];
self.commodityBtn.titleLabel.font = [UIFont systemFontOfSize:14.0];

[self.view addSubview:_commodityBtn];
// 开始扫描二维码
[self startScan];
}

- (void)commodity:(UIButton *)sender{

SecondViewController *svc = [[SecondViewController alloc]init];

[self presentViewController:svc animated:YES completion:nil];

}

- (AVCaptureDevice *)device
{
if (_device == nil) {
_device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
}
return _device;
}

- (AVCaptureDeviceInput *)input
{
if (_input == nil) {
_input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];
}
return _input;
}

- (AVCaptureSession *)session
{
if (_session == nil) {
_session = [[AVCaptureSession alloc] init];
}
return _session;
}

- (AVCaptureVideoPreviewLayer *)previewLayer
{
if (_previewLayer == nil) {
_previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.session];
}
return _previewLayer;
}
// 设置输出对象解析数据时感兴趣的范围
// 默认值是 CGRect(x: 0, y: 0, width: 1, height: 1)
// 通过对这个值的观察, 我们发现传入的是比例
// 注意: 参照是以横屏的左上角作为, 而不是以竖屏
//        out.rectOfInterest = CGRect(x: 0, y: 0, width: 0.5, height: 0.5)
- (AVCaptureMetadataOutput *)output
{
if (_output == nil) {
_output = [[AVCaptureMetadataOutput alloc] init];

//        _output.metadataObjectTypes =@[AVMetadataObjectTypeQRCode];

// 1.获取屏幕的frame
CGRect viewRect = self.view.frame;
// 2.获取扫描容器的frame
CGRect containerRect = self.customContainerView.frame;

CGFloat x = containerRect.origin.y / viewRect.size.height;
CGFloat y = containerRect.origin.x / viewRect.size.width;
CGFloat width = containerRect.size.height / viewRect.size.height;
CGFloat height = containerRect.size.width / viewRect.size.width;

// CGRect outRect = CGRectMake(x, y, width, height);
// [_output rectForMetadataOutputRectOfInterest:outRect];
_output.rectOfInterest = CGRectMake(x, y, width, height);
//        _output.rectOfInterest = CGRectMake(SCREEN_WIDTH/4, SCREEN_HEIGHT/3, SCREEN_WIDTH/2, SCREEN_WIDTH/2);

}
return _output;
}

- (CALayer *)containerLayer
{
if (_containerLayer == nil) {
_containerLayer = [[CALayer alloc] init];

}
return _containerLayer;
}

- (void)startScan
{
// 1.判断输入能否添加到会话中
if (![self.session canAddInput:self.input]) return;
[self.session addInput:self.input];

// 2.判断输出能够添加到会话中
if (![self.session canAddOutput:self.output]) return;
[self.session addOutput:self.output];

// 4.设置输出能够解析的数据类型
// 注意点: 设置数据类型一定要在输出对象添加到会话之后才能设置
self.output.metadataObjectTypes = self.output.availableMetadataObjectTypes;

// 5.设置监听监听输出解析到的数据
[self.output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

// 6.添加预览图层
[self.view.layer insertSublayer:self.previewLayer atIndex:0];
self.previewLayer.frame = self.view.bounds;

// 7.添加容器图层
[self.view.layer addSublayer:self.containerLayer];
self.containerLayer.frame = self.view.bounds;

// 8.开始扫描
[self.session startRunning];
}

- (void)stopRunning{

[self.session stopRunning];

NSLog(@"%@",_customLabel.text);

SecondViewController *svc = [[SecondViewController alloc]init];

svc.str = _customLabel.text;

[self presentViewController:svc animated:YES completion:nil];

}

- (void)viewWillAppear:(BOOL)animated{

[self.session startRunning];

}

#pragma mark --------AVCaptureMetadataOutputObjectsDelegate ---------
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{

// id 类型不能点语法,所以要先去取出数组中对象
AVMetadataMachineReadableCodeObject *object = [metadataObjects lastObject];

if (object == nil) return;

// 只要扫描到结果就会调用
self.customLabel.text = object.stringValue;

if (!(_customLabel.text == nil)) {

[self stopRunning];

}
// 清除之前的描边
[self clearLayers];

// 对扫描到的二维码进行描边
AVMetadataMachineReadableCodeObject *obj = (AVMetadataMachineReadableCodeObject *)[self.previewLayer transformedMetadataObjectForMetadataObject:object];

// 绘制描边
[self drawLine:obj];

}

- (void)drawLine:(AVMetadataMachineReadableCodeObject *)objc
{
NSArray *array = objc.corners;

// 1.创建形状图层, 用于保存绘制的矩形
CAShapeLayer *layer = [[CAShapeLayer alloc]init];

// 设置线宽
layer.lineWidth = 2;
// 设置描边颜色
layer.strokeColor = [UIColor colorWithRed:174/255.0 green:109/255.0 blue:45/255.0 alpha:1].CGColor;
layer.fillColor = [UIColor clearColor].CGColor;

// 2.创建UIBezierPath, 绘制矩形
UIBezierPath *path = [[UIBezierPath alloc] init];
CGPoint point = CGPointZero;
int index = 0;

CFDictionaryRef dict = (__bridge CFDictionaryRef)(array[index++]);
// 把点转换为不可变字典
// 把字典转换为点，存在point里，成功返回true 其他false
CGPointMakeWithDictionaryRepresentation(dict, &point);

// 设置起点
[path moveToPoint:point];

// 2.2连接其它线段
for (int i = 1; i<array.count; i++) {
CGPointMakeWithDictionaryRepresentation((__bridge CFDictionaryRef)array[i], &point);
[path addLineToPoint:point];
}
// 2.3关闭路径
[path closePath];

layer.path = path.CGPath;
// 3.将用于保存矩形的图层添加到界面上
[self.containerLayer addSublayer:layer];
}

- (void)clearLayers
{
if (self.containerLayer.sublayers)
{
for (CALayer *subLayer in self.containerLayer.sublayers)
{
[subLayer removeFromSuperlayer];
}
}
}

@end

在SecondViewController.h中：

#import <UIKit/UIKit.h>

@interface SecondViewController : UIViewController

@property(strong,nonatomic)NSString *str;

@end

在SecondViewController.m中：

#import "SecondViewController.h"

#define SCREEN_WIDTH [UIScreen mainScreen].bounds.size.width
#define SCREEN_HEIGHT [UIScreen mainScreen].bounds.size.height
@interface SecondViewController ()

@property(strong,nonatomic)UILabel *titleLab;
@property(strong,nonatomic)UILabel *contentLab;

@end

@implementation SecondViewController

- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];

[self titleLabel];
[self contentLabel];

//返回按钮
UIButton *backBtn = [[UIButton alloc]initWithFrame:CGRectMake(20, 100, 50, 35)];
[backBtn addTarget:self action:@selector(back) forControlEvents:UIControlEventTouchUpInside];
backBtn.backgroundColor = [UIColor lightGrayColor];
[backBtn setTitle:@"返回" forState:0];
[self.view addSubview:backBtn];

}

- (void)back{

[self dismissViewControllerAnimated:YES completion:nil];

}

- (void)titleLabel{

self.titleLab = [[UILabel alloc]initWithFrame:CGRectMake(20, 200, SCREEN_WIDTH/2, 30)];
self.titleLab.text = @"扫描获取的数据";
[self.view addSubview:_titleLab];

}

- (void)contentLabel{
self.contentLab = [[UILabel alloc]initWithFrame:CGRectMake(20, 245, SCREEN_WIDTH-40, 30)];
self.contentLab.text = _str;
[self.view addSubview:_contentLab];
}
@end

见面比较简单，可以根据自自己的需求进行点缀，一维码、二维码扫描功能都可以使用。

代码后运行报如下的错误：

This app has crashed because it attempted to access privacy-sensitive data without a usage description. The app's Info.plist must contain an NSCameraUsageDescription key with a string value explaining to the user how the app uses this data.

plist必须包含一个NSCameraUsageDescription，需要去plist中添加。