iOS 原生生成高清二维码

一、 导入 #import 系统库

二、 // 1. 创建一个二维码滤镜实例(CIFilter)

CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];

// 滤镜恢复默认设置

[filter setDefaults];

/** /2. 给滤镜添加数据

传 URL 自动转换为链接

否则为字符信息

*/

NSString *string = @"http:www.baidu.com";

NSData *data = [string dataUsingEncoding:NSUTF8StringEncoding];

// 使用KVC的方式给filter赋值

[filter setValue:data forKeyPath:@"inputMessage"];

// 3. 生成二维码

CIImage *image = [filter outputImage];

// 4. 显示二维码

/**

creatNonInterpolatedUIImageFormCIImage:(CIImage *) withSize:(CGSize *)为 UIimage 扩展类

*/

self.coderImage.image = [UIImage creatNonInterpolatedUIImageFormCIImage:image withSize:200];

---

UIimage 扩展类

          .h

#import@interface UIImage (DBEstension)

//使用下面的方法来获得一个清晰的image

+ (UIImage *)creatNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat)size;

@end

     .m

#import "UIImage+DBEstension.h"

@implementation UIImage (DBEstension)

/**

*  根据CIImage生成指定大小的UIImage

*

*  @param image CIImage

*  @param size  图片宽度  越大越清晰

*

*  @return 生成的高清的UIImage

*/

+ (UIImage *)creatNonInterpolatedUIImageFormCIImage:(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图片

CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

CGContextRelease(bitmapRef);

CGImageRelease(bitmapImage);

return [UIImage imageWithCGImage:scaledImage];

}

@end