public Captcha()
{
CleanUp();
var rnd = new Random();
int randNumber = rnd.Next((int)Math.Pow(10, Digits));
using var img = new Image <Rgba32>(Width, Height);
var font = new FontCollection()
.Install(System.IO.Path.Combine(RootPath, FontPath))
.CreateFont(30, FontStyle.Regular);
string txt = randNumber.ToString("D" + Digits);
var renderOptions = new RendererOptions(font);
var charSize = new FontRectangle[txt.Length];
for (int i = 0; i < charSize.Length; i++)
{
charSize[i] = TextMeasurer.Measure(txt.Substring(i, 1), renderOptions);
}
float x = ((float)rnd.NextDouble() + 1f) * Width * 0.1f, y;
float spaceSum = Width - 2 * x - charSize.Sum(s => s.Width);
float space;
img.Mutate(ctx =>
{
ctx.Fill(BackColor);
for (int i = 0; i < txt.Length; i++)
{
y = (float)rnd.NextDouble() * (Height - charSize[i].Height);
ctx.Fill(ForeColor,
TextBuilder.GenerateGlyphs(txt.Substring(i, 1), renderOptions)
.Rotate((float)rnd.NextDouble() * .6f - .3f) //almost between -15 and 15
.Translate(x, y));
if (i + 1 < txt.Length)
{
space = (float)rnd.NextDouble() * spaceSum / (Digits - i - 1f);
spaceSum -= space;
x += charSize[i].Width + space;
}
}
for (int i = 0; i < 5; i++)
{
ctx.DrawBeziers(ForeColor, Math.Min(Width, Height) / Digits / 7f,
new PointF((float)rnd.NextDouble() * Width * 0.2f, Height / 4f * (1f + 2f * (float)rnd.NextDouble())),
new PointF(Width / 3f, (float)rnd.NextDouble() * Height),
new PointF(Width / 3f * 2f, (float)rnd.NextDouble() * Height),
new PointF(Width * (1f - (float)rnd.NextDouble() * 0.2f), Height / 4f * (1f + 2f * (float)rnd.NextDouble())));
}
});
Code = BitConverter.ToInt64(Guid.NewGuid().ToByteArray(), 4);
using (var cnnct = new SqlConnection(ConnectionString))
{
using var cmnd = new SqlCommand($@"insert into dbo.CaptchaCodes (Id, Captcha, CreationDate)
values (@id, @captcha, @date)", cnnct);
cmnd.Parameters.Add(new SqlParameter("@id", Code));
cmnd.Parameters.Add(new SqlParameter("@captcha", randNumber));
cmnd.Parameters.Add(new SqlParameter("@date", DateTime.Now));
cnnct.Open();
cmnd.ExecuteNonQuery();
}
var encoder = new PngEncoder {
ColorType = PngColorType.Palette
};
using var mem = new MemoryStream();
img.SaveAsPng(mem, encoder);
Src = "data:image/png;base64," + Convert.ToBase64String(mem.ToArray());
}
