iOS 二维码的生成

#import <CoreImage/CoreImage.h>

/** 生成二维码*/

- (void)set2DimensionalBarCode:(UIImageView *)imgView

{

// 1.实例化二维码滤镜

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

// 2.恢复滤镜的默认属性

[filter setDefaults];

// 3.二维码信息

//NSString *str = @"哎呀我去"; // 展示一串文字

NSString *str = @"http://www.baidu.com"; // 直接打开网页

// 4.将字符串转成二进制数据

NSData *data = [str dataUsingEncoding:NSUTF8StringEncoding];

// 5.通过KVC设置滤镜inputMessage数据

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

// 6.获取滤镜输出的图像

CIImage *outputImage = [filter outputImage];

// 7.将CIImage转成UIImage

//系统默认获取到的二维码图片不太清晰,可以利用这个方法,获取指定大小(传入的size参数值)的二维码图片

UIImage *image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];

// 8.展示二维码

imgView.image = image;

}

/**

*  根据CIImage生成指定大小的UIImage

*

*  @param image CIImage

*  @param size  图片宽度

*/

- (UIImage *)createNonInterpolatedUIImageFormCIImage:(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到图片

CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);

CGContextRelease(bitmapRef);

CGImageRelease(bitmapImage);

return [UIImage imageWithCGImage:scaledImage];

}

转自 YotrolZ