public Image GenerateQRCode(QRCodeParameters param)
{
if (param == null) throw new ArgumentNullException();
QrEncoder encoder = new QrEncoder(ErrorCorrectionLevel.L);
QrCode qrCode = encoder.Encode(param.Text);
GraphicsRenderer gRenderer = new GraphicsRenderer(new FixedModuleSize(param.Size, QuietZoneModules.Two), Brushes.Black, Brushes.White);
MemoryStream ms = new MemoryStream();
gRenderer.WriteToStream(qrCode.Matrix, param.ImageFormat, ms);
return Image.FromStream(ms);
}
private QRCodeParameters ParseQRParamsFromQueryString(IReadableStringCollection query)
{
QRCodeParameters param = new QRCodeParameters();
var text = query["text"];
param.Text = text;
var size = query["size"];
string format = query["format"];
int intSize = 0;
if (int.TryParse(size, out intSize)) param.Size = intSize;
if (!string.IsNullOrWhiteSpace(format) && supportedImageFormats.ContainsKey(format.ToLower())) param.ImageFormat = supportedImageFormats[format];
return param;
}
private void CreateQRCodeImage(HttpContext context, QRCodeParameters param)
{
Image img = null;
if (!cache.TryGetValue(param.ToString(), out img))
{
logger.LogInformation("generating new image");
img = generator.GenerateQRCode(param);
cache.Set(param.ToString(), img, new MemoryCacheEntryOptions() {SlidingExpiration = DateTime.Now.AddDays(1).TimeOfDay });
}
else
{
logger.LogInformation("reading from cache");
}
context.Response.Headers.Add("content-type", "image/" + param.ImageFormat.ToString().ToLower());
img.Save(context.Response.Body, param.ImageFormat);
}