iOS-二維碼產生

標籤：

// 1.建立過濾器    CIFilter *filter = [CIFilter filterWithName:@"CIQRCodeGenerator"];    // 2.恢複預設    [filter setDefaults];    // 3.添加二維碼掃描出來的字串    NSString *dataString = @"這是二維碼掃出來的String";    NSData *data = [dataString dataUsingEncoding:NSUTF8StringEncoding];    [filter setValue:data forKeyPath:@"inputMessage"];    // 4.擷取輸出的二維碼    CIImage *outputImage = [filter outputImage];    // 5.此時的CIImage格式的二維碼會有些模糊，所以將CIImage轉換成UIImage，並放大顯示    self.imageView.image = [self createNonInterpolatedUIImageFormCIImage:outputImage withSize:200];**將CIImage轉換成UIImage的方法**/** * 根據CIImage產生指定大小的UIImage * * @param image CIImage * @param size 圖片寬度 */- (UIImage *)createNonInterpolatedUIImageFormCIImage:(CIImage *)image withSize:(CGFloat) size{    CGRect extent = CGRectIntegral(image.extent);    CGFloat scale = MIN(size/CGRectGetWidth(extent), size/CGRectGetHeight(extent));    // 1.建立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.儲存bitmap到圖片    CGImageRef scaledImage = CGBitmapContextCreateImage(bitmapRef);    CGContextRelease(bitmapRef);    CGImageRelease(bitmapImage);    return [UIImage imageWithCGImage:scaledImage];}

iOS-二維碼產生