CIDetector的初始化方法無效。推測是蘋果API的問題。
生成二維碼圖片
在iOS8及以上版本使用蘋果的API生成二維碼圖片，代碼如下：//encode
- (UIImage *)encodeQRImageWithContent:(NSString *)content size:(CGSize)size { UIImage *codeImage = nil; if (iOS8_OR_LATER) { NSData *stringData = [content dataUsingEncoding: NSUTF8StringEncoding]; //生成 CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"]; [qrFilter setValue:stringData forKey:@"inputMessage"]; [qrFilter setValue:@"M" forKey:@"inputCorrectionLevel"]; UIColor *onColor = [UIColor blackColor]; UIColor *offColor = [UIColor whiteColor]; //上色 CIFilter *colorFilter = [CIFilter filterWithName:@"CIFalseColor" keysAndValues: @"inputImage",qrFilter.outputImage, @"inputColor0",[CIColor colorWithCGColor:onColor.CGColor], @"inputColor1",[CIColor colorWithCGColor:offColor.CGColor], nil]; CIImage *qrImage = colorFilter.outputImage; CGImageRef cgImage = [[CIContext contextWithOptions:nil] createCGImage:qrImage fromRect:qrImage.extent]; UIGraphicsBeginImageContext(size); CGContextRef context = UIGraphicsGetCurrentContext(); CGContextSetInterpolationQuality(context, kCGInterpolationNone); CGContextScaleCTM(context, 1.0, -1.0); CGContextDrawImage(context, CGContextGetClipBoundingBox(context), cgImage); codeImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); CGImageRelease(cgImage); } else { codeImage = [QRCodeGenerator qrImageForString:content imageSize:size.width]; } return codeImage;}iOS8以下使用libqrencode庫來生成二維碼圖片。