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：

#import <Foundation/Foundation.h>

@interface QRCodeGenerator : NSObject

+ (UIImage *)qrImageForString:(NSString *)string imageSize:(CGFloat)size;
+ (UIImage *) twoDimensionCodeImage:(UIImage *)twoDimensionCode withAvatarImage:(UIImage *)avatarImage;
@end

#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;
}

+ (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：

-(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];
[alert show];
}
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
{
if(buttonIndex == 0)
{
[self dismissViewControllerAnimated:YES completion:^
{
[timer invalidate];
}];

}
else
{
[_session startRunning];
}
}