創(chuàng)建二維碼
- (CIImage *) creatQRCodeWithURL:(NSString *)urlStr {
// 1. 實(shí)例化二維碼濾鏡
CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];
// 2. 恢復(fù)濾鏡的默認(rèn)屬性
[filter setDefaults];
// 3. 將字符串轉(zhuǎn)換成
NSData *data = [urlStr dataUsingEncoding:NSUTF8StringEncoding];
// 4. 通過KVO設(shè)置濾鏡inputMessage數(shù)據(jù)
[filter setValue:data forKey:@"inputMessage"];
// 5. 獲得濾鏡輸出的圖像
CIImage *outputImage = [filter outputImage];
return outputImage;
}
改變二維碼大小
- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size {
CGRect extent = CGRectIntegral(image.extent);
CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));
// 創(chuàng)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);
// 保存bitmap到圖片
CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);
CGContextRelease(bitmapRef);
CGImageRelease(bitmapImage);
return [UIImage imageWithCGImage:scaledImage];
}
