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]; }