ios二维码的生成与二维码图片的扫描

/**
*  根据地址生成二维码图片
*
*  @param code 地址字符串
*  @param size 图片的大小
*
*  @return
*/
-(UIImage *)getQRCode:(NSString *)code size:(CGFloat)size {
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
[filter setDefaults];
NSString *dataString = code;
NSData *data = [dataString dataUsingEncoding:NSUTF8StringEncoding];
[filter setValue:data forKeyPath:@"inputMessage"];
CIImage *outputImage = [filter outputImage];
return [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:size];
}

/**
*  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
{
CGRect extent = CGRectIntegral(image.extent);
CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));

// 1.创建bitmap;
size_t width = CGRectGetWidth(extent) * scale;
size_t height = CGRectGetHeight(extent) * scale;
CGColorSpaceRef cs = CGColorSpaceCreateDeviceGray();
CGContextRef bitmapRef = CGBitmapContextCreate(nil, width, height, 8, 0, cs, (CGBitmapInfo)kCGImageAlphaNone);
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef bitmapImage = [context createCGImage:image fromRect:extent];
CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);
CGContextScaleCTM(bitmapRef, scale, scale);
CGContextDrawImage(bitmapRef, extent, bitmapImage);

// 2.保存bitmap到图片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
return [UIImage imageWithCGImage:scaledImage];
}

/**
*  根据二维码图片获取地址
*
*  @param image 二维码图片
*
*  @return
*/
-(NSString *)readQRCodeFromImage:(UIImage *)image{
NSData *data = UIImagePNGRepresentation(image);
CIImage *ciimage = [CIImage imageWithData:data];
if (ciimage) {
CIDetector *qrDetector = [CIDetector detectorOfType:CIDetectorTypeQRCode context:[CIContext contextWithOptions:@{kCIContextUseSoftwareRenderer:@(YES)}] options:@{CIDetectorAccuracy : CIDetectorAccuracyHigh}];
NSArray *resultArr = [qrDetector featuresInImage:ciimage];
if (resultArr.count >0) {
CIFeature *feature = resultArr[0];
CIQRCodeFeature *qrFeature = (CIQRCodeFeature *)feature;
NSString *result = qrFeature.messageString;

return result;
}else{
return nil;
}
}else{
return nil;
}
}