iOS-生成二維碼圖片【附中間帶有小圖標二維碼】（QRCode）

生成二維碼圖片也是項目中常用到的，二維碼的掃描Git上有很多好用的，這里主要說下二維碼的生成

1.普通二維碼

?方法

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

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?方法實現

/**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;}

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2.中間帶有小圖標的二維碼

?方法

/**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;

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?方法實現

/**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;}

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附加方法（與上面兩個方法寫在同一個類）

/** 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];}

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