iOS-生成二维码图片【附中间带有小图标二维码】（QRCode）

生成二维码图片也是项目中常用到的，二维码的扫描Git上有很多好用的，这里主要说下二维码的生成

1.普通二维码

 方法

/**生成二维码QRStering：字符串imageFloat：二维码图片大小*/+ (UIImage *)createQRCodeWithString:(NSString *)QRStering withImgSize:(CGFloat)imageFloat;

 

 方法实现

/**生成二维码QRStering：字符串imageFloat：二维码图片大小*/+ (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"];///获取滤镜输出的图像
CIImage *outImage = [filter outputImage];UIImage *imageV = [self imageWithImageSize:imageFloat withCIIImage:outImage];//返回二维码图像return imageV;}

 

2.中间带有小图标的二维码

 方法

/**生成二维码(中间有小图片)QRStering：字符串centerImage：二维码中间的image对象*/+ (UIImage *)createImgQRCodeWithString:(NSString *)QRString centerImage:(UIImage *)centerImage;

 

 方法实现

/**生成二维码(中间有小图片)QRStering：所需字符串centerImage：二维码中间的image对象*/+ (UIImage *)createImgQRCodeWithString:(NSString *)QRString centerImage:(UIImage *)centerImage{// 创建滤镜对象
CIFilter *filter = [CIFilter filterWithName:@"XiaoGuiGe"];// 恢复滤镜的默认属性
[filter setDefaults];// 将字符串转换成 NSdata
NSData *dataString = [QRString dataUsingEncoding:NSUTF8StringEncoding];// 设置过滤器的输入值, KVC赋值
[filter setValue:dataString forKey:@"inputMessage"];// 获得滤镜输出的图像
CIImage *outImage = [filter outputImage];// 图片小于(27,27),我们需要放大
outImage = [outImage imageByApplyingTransform:CGAffineTransformMakeScale(20, 20)];// 将CIImage类型转成UIImage类型
UIImage *startImage = [UIImage imageWithCIImage:outImage];// 开启绘图, 获取图形上下文
UIGraphicsBeginImageContext(startImage.size);// 把二维码图片画上去 (这里是以图形上下文, 左上角为(0,0)点
[startImage drawInRect:CGRectMake(0, 0, startImage.size.width, startImage.size.height)];// 再把小图片画上去
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)];// 获取当前画得的这张图片
UIImage *qrImage = UIGraphicsGetImageFromCurrentImageContext();// 关闭图形上下文
UIGraphicsEndImageContext();//返回二维码图像return qrImage;}

 

附加方法（与上面两个方法写在同一个类）

/** 将CIImage转换成UIImage 并放大(内部转换使用)*/+ (UIImage *)imageWithImageSize:(CGFloat)size withCIIImage:(CIImage *)ciiImage{CGRect extent = CGRectIntegral(ciiImage.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:ciiImage 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];}