二维码的扫描和生成

一.二维码的扫描

ZBarSDK，一个比较优秀的开源项目，使用起来也很简单。

ZBarSDK是一个开源的SDK，可从这里下载到源码，该SDK实现了识别和读取各种条形码，包括EAN-13/UPC-A, UPC-E, EAN-8, Code 128, Code 39, Interleaved 2 of 5 和 QR Code。

帮助文档：http://zbar.sourceforge.net/iphone/sdkdoc/index.html

// 注意:ZBarSDK的导入用cocoaPods导入,直接手动导入工程会出现错误

Step1.使用ZBarSDK 需要导入的framework

1.AVFoundation.framework

2.CoreMedia.framework

3.CoreVideo.framework

4.QuartzCore.framework

5.libiconv.dylib

Step2.在ViewController.h 导入#import "ZBarSDK.h"

Step3.在ViewController.h 继承 <ZBarReaderDelegate>协议

Step4.写代码：

ViewController.h

?
ViewController.m

?
在界面上放置一个UIImageView/UILabel/UIButton, UIImageView 用于显示扫描到的图像，UILabel用于显示扫描到的信息，UIButton 用于响应事件。
布局如图：



二. 二维码的生成

1.在工程里用CocoaPods导入libqrencode系统包,再导入QRCodeGenerator.h和QRCodeGenerator.m文件

QRCodeGenerator.h文件

//

// QR Code Generator - generates UIImage from NSString

//

// Copyright (C) 2012 http://moqod.com Andrew Kopanev <andrew@moqod.com>

//

// Permission is hereby granted, free of charge, to any person obtaining a copy

// of this software and associated documentation files (the "Software"), to deal

// in the Software without restriction, including without limitation the rights

// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

// of the Software, and to permit persons to whom the Software is furnished to do so,

// subject to the following conditions:

//

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,

// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR

// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE

// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

// DEALINGS IN THE SOFTWARE.

//

#import <Foundation/Foundation.h>

@interface QRCodeGenerator : NSObject

+ (UIImage *)qrImageForString:(NSString *)string imageSize:(CGFloat)size;

@end

QRCodeGenerator.m文件

//

// QR Code Generator - generates UIImage from NSString

//

// Copyright (C) 2012 http://moqod.com Andrew Kopanev <andrew@moqod.com>

//

// Permission is hereby granted, free of charge, to any person obtaining a copy

// of this software and associated documentation files (the "Software"), to deal

// in the Software without restriction, including without limitation the rights

// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies

// of the Software, and to permit persons to whom the Software is furnished to do so,

// subject to the following conditions:

//

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,

// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR

// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE

// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

// DEALINGS IN THE SOFTWARE.

//

#import "QRCodeGenerator.h"

#import "qrencode.h"

enum {

qr_margin = 3

};

@implementation QRCodeGenerator

+ (void)drawQRCode:(QRcode *)code context:(CGContextRef)ctx size:(CGFloat)size {

unsigned char *data = 0;

int width;

data = code->data;

width = code->width;

float zoom = (double)size / (code->width + 2.0 * qr_margin);

CGRect rectDraw = CGRectMake(0, 0, zoom, zoom);

// draw

CGContextSetFillColor(ctx, CGColorGetComponents([UIColor blackColor].CGColor));

for(int i = 0; i < width; ++i) {

for(int j = 0; j < width; ++j) {

if(*data & 1) {

rectDraw.origin = CGPointMake((j + qr_margin) * zoom,(i + qr_margin) * zoom);

CGContextAddRect(ctx, rectDraw);

}

++data;

}

}

CGContextFillPath(ctx);

}

+ (UIImage *)qrImageForString:(NSString *)string imageSize:(CGFloat)size {

if (![string length]) {

return nil;

}

QRcode *code = QRcode_encodeString([string UTF8String], 0, QR_ECLEVEL_L, QR_MODE_8, 1);

if (!code) {

return nil;

}

// create context

CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();

CGContextRef ctx = CGBitmapContextCreate(0, size, size, 8, size * 4, colorSpace, kCGImageAlphaPremultipliedLast);

CGAffineTransform translateTransform = CGAffineTransformMakeTranslation(0, -size);

CGAffineTransform scaleTransform = CGAffineTransformMakeScale(1, -1);

CGContextConcatCTM(ctx, CGAffineTransformConcat(translateTransform, scaleTransform));

// draw QR on this context

[QRCodeGenerator drawQRCode:code context:ctx size:size];

// get image

CGImageRef qrCGImage = CGBitmapContextCreateImage(ctx);

UIImage * qrImage = [UIImage imageWithCGImage:qrCGImage];

// some releases

CGContextRelease(ctx);

CGImageRelease(qrCGImage);

CGColorSpaceRelease(colorSpace);

QRcode_free(code);

return qrImage;

}

@end

2.在prefixHeader中导入libqrencode-prefix.pch文件

3.　在新工程中导入以下框架：AVFoundation.framework、CoreMedia.framework、CoreVideo.framework、QuartzCore.framework、libiconv.dylib（已存在则不需要重新加入）；

③　将libqrencode源码加入工程；

④　需要使用的页面.m文件中引用头文件#import "QRCodeGenerator.h"；

⑤　实现生成二维码图片的方法

//将给定的字符串通过下面方法生成二维码图像

self.contentImageView.image = [QRCodeGenerator qrImageForString:@"hello World" imageSize:self.contentImageView.frame.size.width];