一、扫描

1、  ZBar

ZBar在扫描的灵敏度上，和内存的使用上相对于ZXing上都是较优的，但是对于 “圆角二维码” 的扫描确很困难

2、ZXing

ZXing 是 Google Code上的一个开源的条形码扫描库，是用java设计的，连Google Glass 都在使用的。但有人为了追求更高效率以及可移植性，出现了c++ port. Github上的Objectivc-C port，其实就是用OC代码封装了一下而已，而且已经停止维护。这样效率非常低，在instrument下面可以看到CPU和内存疯涨，在内存小的机器上很容易崩溃。

3、AVFoundation

AVFoundation无论在扫描灵敏度和性能上来说都是最优的，所以毫无疑问我们应该切换到AVFoundation，需要兼容iOS 6或之前的版本可以用zbar或zxing代替。

代码如下：

#import "PUCaptureCodeViewController.h"    #import@interface PUCaptureCodeViewController (){

AVCaptureSession *session;  //扫描会话

AVCaptureDeviceInput *deviceInput;  //输入设备

AVCaptureMetadataOutput *metadataOutput; //输出设备

AVCaptureVideoPreviewLayer *previewLayer;  //预览图层

}

@property (weak, nonatomic) IBOutlet UIImageView *edgeView;  //边沿视图

@property (weak, nonatomic) IBOutlet UITabBar *tabBar;

@property (weak, nonatomic) IBOutlet UIImageView *slinderView;  //冲击波视图

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *sacnLineTop;  //冲击波视图与顶部的约束

@property (weak, nonatomic) IBOutlet NSLayoutConstraint *scanBGViewHight;

@end

@implementation PUCaptureCodeViewController

- (void)viewDidLoad {

[super viewDidLoad];

}

- (void)viewDidAppear:(BOOL)animated{

[super viewDidAppear:animated];

[self layoutUI];

[self startAnimation];

[self startScan];

}

pragma mark private Methods

- (void)layoutUI{

//设置默认的 tabBar

self.tabBar.selectedItem = self.tabBar.items[0];

UIImage *image = [UIImage imageNamed:@"qrcode_border@2x"];

image = [image resizableImageWithCapInsets:UIEdgeInsetsMake(image.size.height/2, image.size.width/2,image.size.height/2, image.size.width/2) resizingMode:UIImageResizingModeStretch];

self.edgesForExtendedLayout = UIRectEdgeNone;

self.edgeView.image = image;

//1、获取扫描会话

session = [[AVCaptureSession alloc]init];

//2. 获取到输入设备

AVCaptureDevice  *device  = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

if (device != nil) {

deviceInput = [[AVCaptureDeviceInput alloc]initWithDevice:device error:nil];

}else{

return;

}

//3、获取到输出设备

metadataOutput = [[AVCaptureMetadataOutput alloc]init];

//4、获取到预览图层

previewLayer = [[AVCaptureVideoPreviewLayer alloc]initWithSession:session];

previewLayer.frame = self.view.frame;

//5. 设置填充模式,不设置填充模式，4s可能会出现问题

previewLayer.videoGravity = AVLayerVideoGravityResizeAspectFill;

}

//开始扫描

- (void)startScan{

//1、判断是否支持输入设备

if(![session canAddInput:deviceInput]){

return;

}

//2、判断是否支持输出设备

if (![session canAddOutput:metadataOutput]) {

return;

}

//3、添加输入设备

[session addInput:deviceInput];

//4. 添加输出设备

[session addOutput:metadataOutput];

//5. 设置输出设备支持的类型,availableMetadataObjectTypes 为设备支持的所有类型

metadataOutput.metadataObjectTypes = metadataOutput.availableMetadataObjectTypes;

//6、设置代理，用于获取扫描的内容

[metadataOutput setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];

//7、添加图层

[self.view.layer insertSublayer:previewLayer atIndex:0];

//8、开始扫描

[session startRunning];

}

- (void)startAnimation{

//设置起始位置

self.sacnLineTop.constant = -300;

//更新约束

[self.view layoutIfNeeded];

//设置动画

[UIView animateWithDuration:3.0 animations:^{

//设置重复次数

[UIView setAnimationRepeatCount:MAXFLOAT];

self.sacnLineTop.constant = self.view.frame.size.height;

[self.view layoutIfNeeded];

}];

}

pragma mark delegate Methods

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

NSLog(@"%@", metadataObjects.lastObject);

// 1. 如果扫描完成，停止会话

[session stopRunning];

// 2. 删除预览图层

[previewLayer removeFromSuperlayer];

NSLog(@"%@", metadataObjects);

// 3. 设置界面显示扫描结果

if (metadataObjects.count > 0){

AVMetadataMachineReadableCodeObject *obj = metadataObjects[0];

// 提示：如果需要对url或者名片等信息进行扫描，可以在此进行扩展！

NSLog(@"%@", obj.stringValue);

}

}

- (void)tabBar:(UITabBar *)tabBar didSelectItem:(UITabBarItem *)item{

self.tabBar.selectedItem = item;

self.scanBGViewHight.constant = item.tag == 0 ? 300 : 300*0.5;

[self.view layoutIfNeeded];

//移除掉所有动画

[self.slinderView.layer removeAllAnimations];

//开始动画

[self startAnimation];

}

@end

二、生成二维码

1、生成二维码的步骤： 导入CoreImage框架 通过滤镜CIFilter生成二维码

二维码的内容(传统的条形码只能放数字)：纯文本,名片,URL

// 1. 实例化二维码滤镜

CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

// 2. 恢复滤镜的默认属性

[filter setDefaults];

// 3. 将字符串转换成

NSData NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];

// 4. 通过KVO设置滤镜inputMessage数据

[filter setValue:data forKey:@"inputMessage"];

// 5. 获得滤镜输出的图像***

CIImage *outputImage = [filter outputImage];

// 6. 将CIImage转换成UIImage，并放大显示

return [UIImage imageWithCIImage:outputImage scale:20.0 orientation:UIImageOrientationUp];

2、生成二维码实例

- (void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

self.imgView=[[UIImageView alloc]initWithFrame:CGRectMake(100, 100, [UIScreen mainScreen].bounds.size.width/2.0, [UIScreen mainScreen].bounds.size.width/2.0)];

[self.view addSubview:_imgView];

[self erweima];

}

pragma mark private Methods

-(void)erweima

{

//二维码滤镜

CIFilter *filter=[CIFilter filterWithName:@"CIQRCodeGenerator"];

//恢复滤镜的默认属性

[filter setDefaults];

//将字符串转换成NSData

NSData *data=[@"www.baidu.com" dataUsingEncoding:NSUTF8StringEncoding];

//通过KVO设置滤镜inputmessage数据

[filter setValue:data forKey:@"inputMessage"];

//获得滤镜输出的图像

CIImage *outputImage=[filter outputImage];

//将CIImage转换成UIImage,并放大显示

_imgView.image=[self createNonInterpolatedUIImageFormCIImage:outputImage withSize:100.0];

//如果还想加上阴影，就在ImageView的Layer上使用下面代码添加阴影

_imgView.layer.shadowOffset=CGSizeMake(0, 0.5);//设置阴影的偏移量

_imgView.layer.shadowRadius=1;//设置阴影的半径

_imgView.layer.shadowColor=[UIColor blackColor].CGColor;//设置阴影的颜色为黑色

_imgView.layer.shadowOpacity=0.3;

}

//改变二维码大小

- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size {

CGRect extent = CGRectIntegral(image.extent);

CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

// 创建bitmap;

size_t width = CGRectGetWidth(extent) * scale;

size_t height = CGRectGetHeight(extent) * scale;

CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();

CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);

CIContext *context = [CIContext contextWithOptions:nil];

CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];

CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);

CGContextScaleCTM(bitmapRef, scale, scale);

CGContextDrawImage(bitmapRef, extent, bitmapImage);

// 保存bitmap到图片

CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

CGContextRelease(bitmapRef);

CGImageRelease(bitmapImage);

return [UIImage imageWithCGImage:scaledImage];

}