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];
}