iOS自带扫描 和 生成二维码

原文地址：iOS自带扫描 和 生成二维码

1.二维码生成

libqrencode介绍：是一个用C语言编写的用来解析二维条形码(QRCode)的程序库，libqrencode通过手机的CCD摄像头来扫描二维条形码。http://pan.baidu.com/s/1eQs1Epk

导入libqrencode库，下面直接代码：

[objc] view
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#import <Foundation/Foundation.h>

@interface QRCodeGenerator : NSObject

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

+ (UIImage *) twoDimensionCodeImage:(UIImage *)twoDimensionCode withAvatarImage:(UIImage *)avatarImage;

@end

[objc] view
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#import "QRCodeGenerator.h"

#import "qrencode.h"

enum {

qr_margin = 3

};

@implementation QRCodeGenerator

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

unsigned charchar *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;

}

+ (UIImage *) twoDimensionCodeImage:(UIImage *)twoDimensionCode withAvatarImage:(UIImage *)avatarImage{

// two-dimension code 二维码

CGSize size = twoDimensionCode.size;

CGSize size2 =CGSizeMake(1.0 / 5.5 * size.width, 1.0 / 5.5 * size.height);

UIGraphicsBeginImageContext(size);

[twoDimensionCode drawInRect:CGRectMake(0, 0, size.width, size.height)];

[[self avatarImage:avatarImage] drawInRect:CGRectMake((size.width - size2.width) / 2.0, (size.height - size2.height) / 2.0, size2.width, size2.height)];

UIImage *resultingImage =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return resultingImage;

}

+ (UIImage *) avatarImage:(UIImage *)avatarImage{

UIImage * avatarBackgroudImage = [UIImage imageNamed:@"icon.png"];

CGSize size = avatarBackgroudImage.size;

UIGraphicsBeginImageContext(size);

[avatarBackgroudImage drawInRect:CGRectMake(0, 0, size.width, size.height)];

[avatarImage drawInRect:CGRectMake(10, 10, size.width - 20, size.height - 20)];

UIImage *resultingImage =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

return resultingImage;

}

@end

2.扫描

iOS7苹果推出了自带的扫描功能，下面直接代码：

[objc] view
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-(void)viewWillAppear:(BOOL)animated

{

[self setupCamera];

}

- (void)setupCamera

{

// Device

_device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

// Input

_input = [AVCaptureDeviceInput deviceInputWithDevice:self.device error:nil];

// Output

_output = [[AVCaptureMetadataOutput alloc]init];

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

// Session

_session = [[AVCaptureSession alloc]init];

[_session setSessionPreset:AVCaptureSessionPresetHigh];

if ([_session canAddInput:self.input])

{

[_session addInput:self.input];

}

if ([_session canAddOutput:self.output])

{

[_session addOutput:self.output];

}

// 条码类型 AVMetadataObjectTypeQRCode

_output.metadataObjectTypes =@[AVMetadataObjectTypeCode128Code,AVMetadataObjectTypeUPCECode,AVMetadataObjectTypeCode39Code,AVMetadataObjectTypeCode39Mod43Code,AVMetadataObjectTypeEAN13Code,AVMetadataObjectTypeEAN8Code,AVMetadataObjectTypeCode93Code,AVMetadataObjectTypePDF417Code,AVMetadataObjectTypeQRCode,AVMetadataObjectTypeAztecCode,AVMetadataObjectTypeInterleaved2of5Code,AVMetadataObjectTypeITF14Code,AVMetadataObjectTypeDataMatrixCode] ;

// Preview

_preview =[AVCaptureVideoPreviewLayer layerWithSession:self.session];

_preview.videoGravity = AVLayerVideoGravityResizeAspectFill;

_preview.frame =CGRectMake(20,110,280,280);

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

// Start

[_session startRunning];

}

#pragma mark AVCaptureMetadataOutputObjectsDelegate

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

{

NSString *stringValue;

if ([metadataObjects count] >0)

{

AVMetadataMachineReadableCodeObject * metadataObject = [metadataObjects objectAtIndex:0];

stringValue = metadataObject.stringValue;

}

[_session stopRunning];

UIAlertView * alert = [[UIAlertView alloc]initWithTitle:@"提示" message:[NSString stringWithFormat:@"结果：%@",stringValue] delegate:self cancelButtonTitle:nil otherButtonTitles:@"知道了",@"重新扫描", nil nil];

[alert show];

}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex

{

if(buttonIndex == 0)

{

[self dismissViewControllerAnimated:YES completion:^

{

[timer invalidate];

}];

}

else

{

[_session startRunning];

}

}