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[操作系统]iOS 中二维码扫描


随着微信的大量推广,越来越多的人会在生活中用到二维码这一个方便大家的功能。

因此,很多的app中也逐渐的都加入了二维码这个元素,今天先给大家介绍一下iOS7后系统自带自己可以手动设计的二维码扫描。

QRCodeViewController这个类是实现二维码扫描创建的类,今天我写的这个类似于官方文档中的实现,可以直接扫描二维码跳转到当前二维码对应的链接,如果是应用的话,会跳转到appStore中对应的应用详情。

 

除了这个,现在用的比较多的还有ZBarSDK等三方库,实现的效果要比自己写的这个漂亮,后面有机会的话,我会介绍一下ZBarSDK的用法以及经常遇到的问题和解决方法。

下面是主要实现:

 

#import "QRCodeViewController.h"

#import <AVFoundation/AVFoundation.h>

 

@interface QRCodeViewController () <AVCaptureMetadataOutputObjectsDelegate>

{

    BOOL _isReading;

}

 

@property (weak, nonatomic) IBOutlet UIView *ShowView;

 

 

@property (nonatomic,strong) UIView *boxView;

//@property (nonatomic,assign) BOOL *isReading;

@property (nonatomic,strong) CALayer *scanLayer;

 

 

@property (nonatomic,strong) UILabel *urlLabel;

 

-(BOOL)startReading;

-(void)stopReading;

 

//捕捉会话

@property (nonatomic,strong) AVCaptureSession *captureSession;

 

//展示layer

@property (nonatomic,strong) AVCaptureVideoPreviewLayer *videoPreviewLayer;

 

@end

 

@implementation QRCodeViewController

 

 

- (void)viewDidLoad {

    [super viewDidLoad];

    

    UIButton *btn = [UIButton buttonWithType:UIButtonTypeSystem];

    btn.frame = CGRectMake(0, 30, 50, 30);

    [btn setImage:[UIImage imageNamed:@"return@2x"] forState:UIControlStateNormal];

    [btn addTarget:self action:@selector(leftClicked) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:btn];

    

    _captureSession = nil;

    //_isReading = NO;

    [self startReading];

    

}

-(void)leftClicked{

    [self dismissViewControllerAnimated:YES completion:nil];

}

 

 

-(BOOL)startReading{

    NSError *error = nil;

    //1.初始化捕捉设备(AVCaptureDevice),类型为AVMediaTypeVideo

    AVCaptureDevice *captureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

    //2.用captureDevice创建输入流

    AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:captureDevice error:&error];

    if (!input) {

        NSLog(@"%@",[error localizedDescription]);

        return NO;

    }

    //3.创建媒体数据输出流

    AVCaptureMetadataOutput *captureMedataOutput = [[AVCaptureMetadataOutput alloc]init];

    //4.实例化捕捉会话

    _captureSession = [[AVCaptureSession alloc]init];

    //4.1将输入流添加到会话

    [_captureSession addInput:input];

    //4.2将媒体输出流添加到会话中

    [_captureSession addOutput:captureMedataOutput];

    //5.创建串行队列,并将媒体输出流添加到队列中

    dispatch_queue_t dispatchQueue;

    dispatchQueue = dispatch_queue_create("myQueue", NULL);

    //5.1设置代理

    [captureMedataOutput setMetadataObjectsDelegate:self queue:dispatchQueue];

    

    //5.2设置输出媒体数据类型为QRCode

    [captureMedataOutput setMetadataObjectTypes:[NSArray arrayWithObject:AVMetadataObjectTypeQRCode]];

    //6.实例化预览图层

    _videoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc]initWithSession:_captureSession];

    //7.设置预览图层填充方式

    [_videoPreviewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];

    //8.设置图层的frame

    [_videoPreviewLayer setFrame:_ShowView.layer.bounds];

    //9.将图层添加到预览view的图层上

    [_ShowView.layer addSublayer:_videoPreviewLayer];

    //10.设置扫描范围

    captureMedataOutput.rectOfInterest = CGRectMake(0.2f, 0.2f, 0.8f, 0.8f);

    //10.1. 设置扫描框

    _boxView = [[UIView alloc]initWithFrame:CGRectMake(_ShowView.bounds.size.width * 0, _ShowView.bounds.size.height*0, _ShowView.bounds.size.width, _ShowView.bounds.size.height)];

    _boxView.layer.borderColor = [UIColor greenColor].CGColor;

    _boxView.layer.borderWidth = 1.0f;

    [_ShowView addSubview:_boxView];

    

    //10.2扫描线

    _scanLayer = [[CALayer alloc]init];

    _scanLayer.frame = CGRectMake(0, 0, _boxView.bounds.size.width, 2);

    _scanLayer.backgroundColor = [UIColor cyanColor].CGColor;

    [_boxView.layer addSublayer:_scanLayer];

    NSTimer *timer = [NSTimer scheduledTimerWithTimeInterval:0.2f target:self selector:@selector(moveScanLayer:) userInfo:nil repeats:YES];

    [timer fire];

    

    //11.开始扫描

    [_captureSession startRunning];

    

    return 1;

}

 

-(void)moveScanLayer:(NSTimer *)timer{

    CGRect frame = _scanLayer.frame;

    if (_boxView.frame.size.height <= _scanLayer.frame.origin.y) {

        frame.origin.y = 0;

        _scanLayer.frame = frame;

    }

    else{

        frame.origin.y += 5;

        [UIView animateWithDuration:0.1 animations:^{

            _scanLayer.frame = frame;

        }];

    }

}

 

 

-(void)stopReading{

//    [_captureSession stopRunning];

//    _captureSession = nil;

//    [_scanLayer removeFromSuperlayer];

//    [_videoPreviewLayer removeFromSuperlayer];

}

 

 

#pragma mark - AVCaptureMetadataOutputObjectsDelegate

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

    //判断是否有数据

    if (metadataObjects !=nil && [metadataObjects count]>0) {

        AVMetadataMachineReadableCodeObject *metadataObj = [metadataObjects objectAtIndex:0];

        //判断回传的数据类型

        if ([[metadataObj type] isEqualToString:AVMetadataObjectTypeQRCode]) {

            [self performSelectorOnMainThread:@selector(setUrl:) withObject:[metadataObj stringValue] waitUntilDone:NO];

            

            //[[UIApplication sharedApplication] openURL:url];

            [self performSelectorOnMainThread:@selector(stopReading) withObject:nil waitUntilDone:NO];

            _isReading = NO;

        }

    }

}

 

-(void)setUrl:(NSString *)text{

    NSURL *url = [NSURL URLWithString:text];

    [[UIApplication sharedApplication] openURL:url];

}