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!
每日更新关注:http://weibo.com/hanjunqiang 新浪微博
指示根视图:
- self.window.rootViewController = [[UINavigationController alloc]initWithRootViewController:[SecondViewController new]];
生成二维码:
- // 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 = @"http://www.baidu.com";
- }
- - (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:
- // Created by 韩俊强 on 15/11/27.
- // Copyright (c) 2015年 韩俊强. All rights reserved.
- //
- #import "RootViewController.h"
- #import <AVFoundation/AVFoundation.h>
- @interface RootViewController ()<AVCaptureMetadataOutputObjectsDelegate,UIAlertViewDelegate>
- @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 nil];
- [alert show];
- }
- }
- - (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
- {
- [self.session startRunning];
- }
每日更新关注:http://weibo.com/hanjunqiang 新浪微博
每日更新关注:http://weibo.com/hanjunqiang 新浪微博
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：
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@interface ViewController ()<AVCaptureMetadataOutputObjectsDelegate>
//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];
}
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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：
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-(
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);
}
}
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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
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output.rectOfInterest=CGRectMake(0.5,0,0.5, 1);
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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。
每日更新关注:http://weibo.com/hanjunqiang 新浪微博
原文地址：http://blog.csdn.net/qq_31810357/article/details/50442512
