本文共 9234 字,大约阅读时间需要 30 分钟。
最近大家总是问我有没有关于二维码的demo,为了满足大家的需求,特此研究了一番,希望能帮到大家!
指示根视图:
1 | self.window.rootViewController = [[UINavigationController alloc]initWithRootViewController:[SecondViewController new ]]; |
生成二维码:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 | // Created by 韩俊强 on 15/11/27. // Copyright (c) 2015年 韩俊强. All rights reserved. // # import "SecondViewController.h" @interface SecondViewController () @property (nonatomic, strong) UITextField *tfCode; @property (nonatomic, strong) UIButton *btnGenerate; @property (nonatomic, strong) UIImageView *imageView; @end @implementation SecondViewController - ( void )viewDidLoad { [ super viewDidLoad]; CGSize windowSize = [UIScreen mainScreen].bounds.size; self.tfCode = [[UITextField alloc] initWithFrame:CGRectMake( 10 , 64 , windowSize.width- 100 , 40 )]; [self.view addSubview:self.tfCode]; self.tfCode.borderStyle = UITextBorderStyleRoundedRect; self.btnGenerate = [[UIButton alloc] initWithFrame:CGRectMake(windowSize.width- 100 , 64 , 90 , 40 )]; [self.view addSubview:self.btnGenerate]; [self.btnGenerate addTarget:self action: @selector (actionGenerate) forControlEvents:UIControlEventTouchUpInside]; self.btnGenerate.backgroundColor = [UIColor lightGrayColor]; [self.btnGenerate setTitle:@ "生成" forState:UIControlStateNormal]; [self.btnGenerate setTitleColor:[UIColor blackColor] forState:UIControlStateNormal]; self.imageView = [[UIImageView alloc] initWithFrame:CGRectMake( 0 , 0 , 300 , 300 )]; [self.view addSubview:self.imageView]; self.imageView.center = CGPointMake(windowSize.width/ 2 , windowSize.height/ 2 ); self.tfCode.text = @ "" ; } - ( void )actionGenerate { NSString *text = self.tfCode.text; NSData *stringData = [text dataUsingEncoding: NSUTF8StringEncoding]; //生成 CIFilter *qrFilter = [CIFilter filterWithName:@ "CIQRCodeGenerator" ]; [qrFilter setValue:stringData forKey:@ "inputMessage" ]; [qrFilter setValue:@ "M" forKey:@ "inputCorrectionLevel" ]; UIColor *onColor = [UIColor blackColor]; UIColor *offColor = [UIColor whiteColor]; //上色 CIFilter *colorFilter = [CIFilter filterWithName:@ "CIFalseColor" keysAndValues:@ "inputImage" ,qrFilter.outputImage,@ "inputColor0" ,[CIColor colorWithCGColor:onColor.CGColor],@ "inputColor1" ,[CIColor colorWithCGColor:offColor.CGColor],nil]; CIImage *qrImage = colorFilter.outputImage; //绘制 CGSize size = CGSizeMake( 300 , 300 ); CGImageRef cgImage = [[CIContext contextWithOptions:nil] createCGImage:qrImage fromRect:qrImage.extent]; UIGraphicsBeginImageContext(size); CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetInterpolationQuality(context, kCGInterpolationNone); CGContextScaleCTM(context, 1.0 , - 1.0 ); CGContextDrawImage(context, CGContextGetClipBoundingBox(context), cgImage); UIImage *codeImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); CGImageRelease(cgImage); self.imageView.image = codeImage; } |
扫描二维码:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 | // Created by 韩俊强 on 15/11/27. // Copyright (c) 2015年 韩俊强. All rights reserved. // # import "RootViewController.h" # import @interface RootViewController () @property (nonatomic, strong) UIView *scanRectView; // 硬件设备 @property (strong, nonatomic) AVCaptureDevice *device; //输入设备 @property (strong, nonatomic) AVCaptureDeviceInput *input; //输出设备 @property (strong, nonatomic) AVCaptureMetadataOutput *output; //桥梁.连接输入和输出设备, @property (strong, nonatomic) AVCaptureSession *session; @property (strong, nonatomic) AVCaptureVideoPreviewLayer *preview; @end @implementation RootViewController - ( void )viewDidLoad { [ super viewDidLoad]; CGSize windowSize = [UIScreen mainScreen].bounds.size; CGSize scanSize = CGSizeMake(windowSize.width* 3 / 4 , windowSize.width* 3 / 4 ); CGRect scanRect = CGRectMake((windowSize.width-scanSize.width)/ 2 , (windowSize.height-scanSize.height)/ 2 , scanSize.width, scanSize.height); scanRect = CGRectMake(scanRect.origin.y/windowSize.height, scanRect.origin.x/windowSize.width, scanRect.size.height/windowSize.height,scanRect.size.width/windowSize.width); self.device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; self.input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil]; self.output = [[AVCaptureMetadataOutput alloc]init]; [self.output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()]; self.session = [[AVCaptureSession alloc]init]; [self.session setSessionPreset:([UIScreen mainScreen].bounds.size.height< 500 )?AVCaptureSessionPreset640x480:AVCaptureSessionPresetHigh]; [self.session addInput:self.input]; [self.session addOutput:self.output]; self.output.metadataObjectTypes=@[AVMetadataObjectTypeQRCode]; self.output.rectOfInterest = scanRect; self.preview = [AVCaptureVideoPreviewLayer layerWithSession:self.session]; self.preview.videoGravity = AVLayerVideoGravityResizeAspectFill; self.preview.frame = [UIScreen mainScreen].bounds; [self.view.layer insertSublayer:self.preview atIndex: 0 ]; self.scanRectView = [UIView new ]; [self.view addSubview:self.scanRectView]; self.scanRectView.frame = CGRectMake( 0 , 0 , scanSize.width, scanSize.height); self.scanRectView.center = CGPointMake(CGRectGetMidX([UIScreen mainScreen].bounds), CGRectGetMidY([UIScreen mainScreen].bounds)); self.scanRectView.layer.borderColor = [UIColor redColor].CGColor; self.scanRectView.layer.borderWidth = 1 ; //开始捕获 [self.session startRunning]; } - ( void )captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection { if ( (metadataObjects.count== 0 ) ) { return ; } if (metadataObjects.count> 0 ) { [self.session stopRunning]; AVMetadataMachineReadableCodeObject *metadataObject = metadataObjects.firstObject; //输出扫描字符串 UIAlertView *alert = [[UIAlertView alloc] initWithTitle:metadataObject.stringValue message:@ "" delegate:self cancelButtonTitle:@ "ok" otherButtonTitles: nil]; [alert show]; } } - ( void )alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex { [self.session startRunning]; }</avcapturemetadataoutputobjectsdelegate,uialertviewdelegate></avfoundation> |
最终效果:(由于扫描二维码无法展示效果,所以自己动手真机测试吧!)
IOS7之前,开发者进行扫码编程时,一般会借助第三方库。常用的是ZBarSDK,IOS7之后,系统的AVMetadataObject类中,为我们提供了解析二维码的接口。经过测试,使用原生API扫描和处理的效率非常高,远远高于第三方库。
一、使用方法示例
官方提供的接口非常简单,代码如下:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 | @interface ViewController () //用于处理采集信息的代理 { AVCaptureSession * session; //输入输出的中间桥梁 } @end @implementation ViewController - ( void )viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. //获取摄像设备 AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; //创建输入流 AVCaptureDeviceInput * input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil]; //创建输出流 AVCaptureMetadataOutput * output = [[AVCaptureMetadataOutput alloc]init]; //设置代理 在主线程里刷新 [output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()]; //初始化链接对象 session = [[AVCaptureSession alloc]init]; //高质量采集率 [session setSessionPreset:AVCaptureSessionPresetHigh]; [session addInput:input]; [session addOutput:output]; //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,AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeCode128Code]; AVCaptureVideoPreviewLayer * layer = [AVCaptureVideoPreviewLayer layerWithSession:session]; layer.videoGravity=AVLayerVideoGravityResizeAspectFill; layer.frame=self.view.layer.bounds; [self.view.layer insertSublayer:layer atIndex:0]; //开始捕获 [session startRunning]; } |
之后我们的UI上已经可以看到摄像头捕获的内容,只要实现代理中的方法,就可以完成二维码条形码的扫描:
1 2 3 4 5 6 7 8 | -( void )captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection{ if (metadataObjects.count>0) { //[session stopRunning]; AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex : 0 ]; //输出扫描字符串 NSLog(@ "%@" ,metadataObject.stringValue); } } |
二、一些优化
通过上面的代码测试,我们可以发现系统的解析处理效率是相当的高,IOS官方提供的API也确实非常强大,然而,我们可以做进一步的优化,将效率更加提高:
首先,AVCaptureMetadataOutput类中有一个这样的属性(在IOS7.0之后可用):
@property(nonatomic) CGRect rectOfInterest;
这个属性大致意思就是告诉系统它需要注意的区域,大部分APP的扫码UI中都会有一个框,提醒你将条形码放入那个区域,这个属性的作用就在这里,它可以设置一个范围,只处理在这个范围内捕获到的图像的信息。如此一来,可想而知,我们代码的效率又会得到很大的提高,在使用这个属性的时候。需要几点注意:
1、这个CGRect参数和普通的Rect范围不太一样,它的四个值的范围都是0-1,表示比例。
2、经过测试发现,这个参数里面的x对应的恰恰是距离左上角的垂直距离,y对应的是距离左上角的水平距离。
3、宽度和高度设置的情况也是类似。
3、举个例子如果我们想让扫描的处理区域是屏幕的下半部分,我们这样设置
1 | output.rectOfInterest=CGRectMake(0.5,0,0.5, 1); |
具体apple为什么要设计成这样,或者是这个参数我的用法那里不对,还需要了解的朋友给个指导。
转自:http://www.2cto.com/kf/201601/456033.html
另外有一个支持64为编译的二维码生成库下载地址:http://download.csdn.net/download/u011148716/8315981
如果只是生成的話,see
https://github.com/moky/slanissue-ios/blob/master/uikit_ext/S9QRCodeImage.h
用法:
UIImage *qrImage = [UIImage imageWithQRCode:@"你的文字" size:256];
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