iOS7之后系统自带生成二维码

先在控制器里面创建一个UIimageView来充当二维码的容器

CGFloatqrImageViewWH =SP(190);

CGFloatqrImageViewX =0.5*(SCREEN_WIDTH- qrImageViewWH);

UIImageView* qrImageView = [[UIImageViewalloc]initWithFrame:CGRectMake(qrImageViewX, iconImageView.bottom+SP(35), qrImageViewWH, qrImageViewWH)];

qrImageView.backgroundColor= [UIColorrandomColor];

[self.viewaddSubview:qrImageView];

self.qrImageView= qrImageView;//在此记得设置为成员变量

然后调用生成二维码的方法

#pragma mark - creatQR

- (void)creatQR

{

//创建过滤器

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

//恢复默认

[filtersetDefaults];

//给过滤器添加数据http://www.txship.com/

NSString* dataStr =@"http://www.txship.com";

NSData* data = [dataStrdataUsingEncoding:NSUTF8StringEncodingallowLossyConversion:YES];

//通过KVO设置滤镜inputMessage数据

[filtersetValue:dataforKey:@"inputMessage"];

//获取输出的二维码

CIImage* qrImage = [filteroutputImage];

//将CIImage装换为UIimage并放大显示

self.qrImageView.image= [self createNonInterpolatedUIImageFormCIImage:qrImage withSize:SP(190)];

}

这样就可以生成一个二维码了，但是这样生成的二维码不清晰

可以调用下面方法来还原二维码的清晰度，把输出的二维码传到这个方法中，同时设置二维码的尺寸 你会得到一个全新的 UIimage 再复制给全局变量装二维码的容器中

/**

*根据CIImage生成指定大小的UIImage

*

*@param image CIImage

*@param size图片宽度

*/

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

{

CGRectextent =CGRectIntegral(image.extent);

CGFloatscale =MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

// 1.创建bitmap;

size_twidth =CGRectGetWidth(extent) * scale;

size_theight =CGRectGetHeight(extent) * scale;

CGColorSpaceRefcs =CGColorSpaceCreateDeviceGray();

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

CIContext*context = [CIContextcontextWithOptions:nil];

CGImageRefbitmapImage = [contextcreateCGImage:imagefromRect:extent];

CGContextSetInterpolationQuality(bitmapRef,kCGInterpolationNone);

CGContextScaleCTM(bitmapRef, scale, scale);

CGContextDrawImage(bitmapRef, extent, bitmapImage);

// 2.保存bitmap到图片

CGImageRefscaledImage =CGBitmapContextCreateImage(bitmapRef);

CGContextRelease(bitmapRef);

CGImageRelease(bitmapImage);

return[UIImageimageWithCGImage:scaledImage];

}

截图功能

传进入你想要截图的view  然后会返回给你一个UIImage对象

#pragma mark -截图功能

-(UIImage*)captureImageFromView:(UIView*)view

{

CGRectscreenRect = [viewbounds];

UIGraphicsBeginImageContext(screenRect.size);

CGContextRefctx =UIGraphicsGetCurrentContext();

[view.layerrenderInContext:ctx];

UIImage* image =UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

returnimage;

}

/**

*  根据CIImage生成指定大小的UIImage

*

*  @param image CIImage

*  @param size  图片宽度

*/- (UIImage*)createNonInterpolatedUIImageFormCIImage:(CIImage*)image withSize:(CGFloat) size{CGRectextent =CGRectIntegral(image.extent);CGFloatscale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));// 1.创建bitmap;size_t width =CGRectGetWidth(extent) * scale;    size_t height =CGRectGetHeight(extent) * scale;CGColorSpaceRefcs =CGColorSpaceCreateDeviceGray();CGContextRefbitmapRef =CGBitmapContextCreate(nil, width, height,8,0, cs, (CGBitmapInfo)kCGImageAlphaNone);CIContext*context = [CIContextcontextWithOptions:nil];CGImageRefbitmapImage = [context createCGImage:image fromRect:extent];CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);CGContextScaleCTM(bitmapRef, scale, scale);CGContextDrawImage(bitmapRef, extent, bitmapImage);// 2.保存bitmap到图片CGImageRefscaledImage =CGBitmapContextCreateImage(bitmapRef);CGContextRelease(bitmapRef);CGImageRelease(bitmapImage);return[UIImageimageWithCGImage:scaledImage];}

二维码的扫描

// 1.创建捕捉会话AVCaptureSession*session = [[AVCaptureSessionalloc] init];self.session= session;// 2.添加输入设备(数据从摄像头输入)AVCaptureDevice*device = [AVCaptureDevicedefaultDeviceWithMediaType:AVMediaTypeVideo];AVCaptureDeviceInput*input = [AVCaptureDeviceInputdeviceInputWithDevice:device error:nil];    [session addInput:input];// 3.添加输出数据(示例对象-->类对象-->元类对象-->根元类对象)AVCaptureMetadataOutput*output = [[AVCaptureMetadataOutputalloc] init];    [output setMetadataObjectsDelegate:selfqueue:dispatch_get_main_queue()];    [session addOutput:output];// 3.1.设置输入元数据的类型(类型是二维码数据)[output setMetadataObjectTypes:@[AVMetadataObjectTypeQRCode]];// 4.添加扫描图层AVCaptureVideoPreviewLayer*layer = [AVCaptureVideoPreviewLayerlayerWithSession:session];    layer.frame=self.view.bounds;    [self.view.layeraddSublayer:layer];self.layer= layer;// 5.开始扫描[session startRunning];

扫描到结果后会调用的方法

// 当扫描到数据时就会执行该方法- (void)captureOutput:(AVCaptureOutput*)captureOutput didOutputMetadataObjects:(NSArray*)metadataObjects fromConnection:(AVCaptureConnection*)connection{if(metadataObjects.count>0) {//获得扫描数据，最后一个时最新扫描的数据AVMetadataMachineReadableCodeObject*object = [metadataObjects lastObject];NSLog(@"%@", object.stringValue);// 停止扫描[self.sessionstopRunning];// 将预览图层移除[self.layerremoveFromSuperlayer];    }else{NSLog(@"没有扫描到数据");    }}