iOS开发中使用CIFilter生成二维码和条形码

版权声明：本文为博主原创文章，未经博主允许不得转载。 https://cloud.tencent.com/developer/article/1337682

在iOS7之后我们可以使用苹果自带的CIFilter这个类生成二维码，我们可以通过为UIImage这个类添加一个分类来实现该功能。代码：

• (UIImage *)qrCodeImageWithInfo:(NSString *)info  width:(CGFloat)width

{

if (!info) {

return nil;

    }

NSData *strData = info dataUsingEncoding:NSUTF8StringEncoding allowLossyConversion:NO;

//创建二维码滤镜

CIFilter *qrFilter = CIFilter filterWithName:@"CIQRCodeGenerator";

    qrFilter setValue:strData forKey:@"inputMessage";

    qrFilter setValue:@"H" forKey:@"inputCorrectionLevel";

CIImage *qrImage = qrFilter.outputImage;

//颜色滤镜

CIFilter *colorFilter = CIFilter filterWithName:@"CIFalseColor";

    colorFilter setDefaults;

    colorFilter setValue:qrImage forKey:kCIInputImageKey;

//    [colorFilter setValue:CIColor colorWithRed:0 green:0 blue:0 forKey:@"inputColor0"];

//    undefinedcolorFilter setValue:CIColor colorWithRed:1 green:1 blue:1 forKey:@"inputColor1"];

CIImage *colorImage = colorFilter.outputImage;

//返回二维码

CGFloat scale = width/31;

UIImage *codeImage = [UIImage imageWithCIImage:colorImage imageByApplyingTransform:CGAffineTransformMakeScale(scale, scale)];

return codeImage;

}

在iOS8之后我们还可以使用CIFilter这个类来生成条形码，我们同样可以通过为UIImage这个类添加分类的方法来实现该功能。代码：

• (UIImage *)barCodeImageWithInfo:(NSString *)info

{

// 1.将字符串转换成NSData

NSData *data = info dataUsingEncoding:NSUTF8StringEncoding;

// 2.创建条形码滤镜

CIFilter *filter = CIFilter filterWithName:@"CICode128BarcodeGenerator";

// 3.恢复滤镜的默认属性

    filter setDefaults;

// 4.设置滤镜inputMessage数据

    filter setValue:data forKey:@"inputMessage";

// 5.获得滤镜输出的图像

CIImage *urlImage = filter outputImage;

// 6.将CIImage 转换为UIImage

UIImage *image = UIImage imageWithCIImage:urlImage;

return image;

}