/** 生成二維碼 QRStering：字符串 imageFloat：二維碼圖片大小 */+ (UIImage *)createQRCodeWithString:(NSString *)QRStering withImgSize:(CGFloat)imageFloat;

/** 生成二維碼 QRStering：字符串 imageFloat：二維碼圖片大小 */+ (UIImage *)createQRCodeWithString:(NSString *)QRString withImgSize:(CGFloat)imageFloat{  CIFilter *filter = [CIFilter filterWithName:@"XiaoGuiGe"];  [filter setDefaults];  NSString *getString = QRString;  NSData *dataString = [getString dataUsingEncoding:NSUTF8StringEncoding];  [filter setValue:dataString forKey:@"inputMessage"];  ///獲取濾鏡輸出的圖像  CIImage *outImage = [filter outputImage];  UIImage *imageV = [self imageWithImageSize:imageFloat withCIIImage:outImage];  //返回二維碼圖像  return imageV;}

/** 生成二維碼(中間有小圖片) QRStering：字符串 centerImage：二維碼中間的image對象 */+ (UIImage *)createImgQRCodeWithString:(NSString *)QRString centerImage:(UIImage *)centerImage;

/** 生成二維碼(中間有小圖片) QRStering：所需字符串 centerImage：二維碼中間的image對象 */+ (UIImage *)createImgQRCodeWithString:(NSString *)QRString centerImage:(UIImage *)centerImage{  // 創建濾鏡對象  CIFilter *filter = [CIFilter filterWithName:@"XiaoGuiGe"];  // 恢復濾鏡的默認屬性  [filter setDefaults];  // 將字符串轉換成 NSdata  NSData *dataString = [QRString dataUsingEncoding:NSUTF8StringEncoding];  // 設置過濾器的輸入值, KVC賦值  [filter setValue:dataString forKey:@"inputMessage"];  // 獲得濾鏡輸出的圖像  CIImage *outImage = [filter outputImage];  // 圖片小于(27,27),我們需要放大  outImage = [outImage imageByApplyingTransform:CGAffineTransformMakeScale(20, 20)];  // 將CIImage類型轉成UIImage類型  UIImage *startImage = [UIImage imageWithCIImage:outImage];  // 開啟繪圖, 獲取圖形上下文  UIGraphicsBeginImageContext(startImage.size);  // 把二維碼圖片畫上去 (這里是以圖形上下文, 左上角為(0,0)點  [startImage drawInRect:CGRectMake(0, 0, startImage.size.width, startImage.size.height)];  // 再把小圖片畫上去  CGFloat icon_imageW = 200;  CGFloat icon_imageH = icon_imageW;  CGFloat icon_imageX = (startImage.size.width - icon_imageW) * 0.5;  CGFloat icon_imageY = (startImage.size.height - icon_imageH) * 0.5;  [centerImage drawInRect:CGRectMake(icon_imageX, icon_imageY, icon_imageW, icon_imageH)];  // 獲取當前畫得的這張圖片  UIImage *qrImage = UIGraphicsGetImageFromCurrentImageContext();  // 關閉圖形上下文  UIGraphicsEndImageContext();  //返回二維碼圖像  return qrImage;}

/** 將CIImage轉換成UIImage 并放大(內部轉換使用)*/+ (UIImage *)imageWithImageSize:(CGFloat)size withCIIImage:(CIImage *)ciiImage{  CGRect extent = CGRectIntegral(ciiImage.extent);  CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));  // 1.創建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:ciiImage fromRect:extent];  CGContextSetInterpolationQuality(bitmapRef, kCGInterpolationNone);  CGContextScaleCTM(bitmapRef, scale, scale);  CGContextDrawImage(bitmapRef, extent, bitmapImage);  // 2.保存bitmap到圖片  CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);  CGContextRelease(bitmapRef);  CGImageRelease(bitmapImage);  return [UIImage imageWithCGImage:scaledImage];}