需要导入：QuartzCore.framework，CoreVideo.framework，CoreMedia.framework，AVFoundation.framework，CoreImage.framework
调用： [self.QRImgview setImage:[Common qrCodeImageWithString:[Common dictionaryToJson:self.dic]]];
+(UIImage*)qrCodeImageWithString:(NSString*)str{
if (str && [str isKindOfClass:[NSString class]] && str.length > 0) {
return [self createNonInterpolatedUIImageFromCIImage:[self createQRForString:str]
withScale:2*[[UIScreen mainScreen] scale]];
}
return nil;
}
+ (CIImage *)createQRForString:(NSString *)qrString
{
// Need to convert the string to a UTF-8 encoded NSData object
NSData *stringData = [qrString dataUsingEncoding: NSUTF8StringEncoding];
// Create the filter
CIFilter *qrFilter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// Set the message content and error-correction level
[qrFilter setValue:stringData forKey:@"inputMessage"];
[qrFilter setValue:@"H" forKey:@"inputCorrectionLevel"];
// Send the image back
return qrFilter.outputImage;
}
+ (UIImage *)createNonInterpolatedUIImageFromCIImage:(CIImage *)image withScale:(CGFloat)scale
{
// Render the CIImage into a CGImage
CGImageRef cgImage = [[CIContext contextWithOptions:nil] createCGImage:image fromRect:image.extent];
// Now we'll rescale using CoreGraphics
UIGraphicsBeginImageContext(CGSizeMake(image.extent.size.width * scale, image.extent.size.width * scale));
CGContextRef context = UIGraphicsGetCurrentContext();
// We don't want to interpolate (since we've got a pixel-correct image)
CGContextSetInterpolationQuality(context, kCGInterpolationNone);
CGContextDrawImage(context, CGContextGetClipBoundingBox(context), cgImage);
// Get the image out
UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
// Tidy up
UIGraphicsEndImageContext();
CGImageRelease(cgImage);
return scaledImage;
}
