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];

}