/// <summary>
/// Creates a captcha image for specified <see cref="IDrawingModel" /> and write it in response.
/// </summary>
/// <param name="response">
/// The specified <see cref="HttpResponseBase" />.
/// </param>
/// <param name="drawingModel">
/// The specified <see cref="IDrawingModel" />.
/// </param>
public virtual void WriteCaptchaImage(HttpResponseBase response, IDrawingModel drawingModel)
{
Validate.ArgumentNotNull(response, "response");
Validate.ArgumentNotNull(drawingModel, "drawingModel");
using (Bitmap bitmap = CaptchaUtils.ImageGeneratorFactory(drawingModel).Generate(drawingModel))
{
response.ContentType = "image/gif";
bitmap.Save(response.OutputStream, ImageFormat.Gif);
}
}
/// <summary>
/// Generates a new captcha image.
/// </summary>
public virtual void Generate()
{
var parameterContainer = new RequestParameterContainer(Request);
try
{
if (Request.UrlReferrer.AbsolutePath == Request.Url.AbsolutePath)
{
throw new InvalidOperationException();
}
IDrawingModel drawingModel =
CaptchaUtils.CaptchaManagerFactory(parameterContainer).GetDrawingModel(parameterContainer);
CaptchaUtils.BuilderProviderFactory(parameterContainer).WriteCaptchaImage(Response, drawingModel);
}
catch (Exception)
{
CaptchaUtils.BuilderProviderFactory(parameterContainer).WriteErrorImage(Response);
}
}
public void Drawing(Point point, Boolean lastPoint = false)
{
if (IsDrawing)
{
try
{
if (dictPaintModel.TryGetValue(ShapeType.FullName, out string painterTypeStr))
{
var painterType = Type.GetType(painterTypeStr);
IDrawingModel painterModel = (IDrawingModel)Activator.CreateInstance(painterType);
painterModel.SetModel(selectedItem);
painterModel.Drawing(point, painterParams);
}
}
catch (Exception e)
{
MessageBox.Show(e.Message, "Ошибка");
}
//lineEndPoint = point;
//if ( selectedItem == null )
//{
// selectedItem = Activator.CreateInstance( shapeType );
// drawCanvas.Children.Add( selectedItem );
// selectedItem.X1 = point.X;
// selectedItem.Y1 = point.Y;
//}
//selectedItem.X2 = lineEndPoint.X;
//selectedItem.Y2 = lineEndPoint.Y;
//selectedItem.Stroke = brush;
//selectedItem.StrokeThickness = 2;
}
}
/// <summary>
/// Creates a captcha image using the specified <see cref="IDrawingModel" />.
/// </summary>
/// <param name="drawingModel">
/// The specified <see cref="IDrawingModel" />.
/// </param>
/// <returns>
/// An instance of <see cref="Bitmap" />.
/// </returns>
public Bitmap Generate(IDrawingModel drawingModel)
{
var random = new Random();
string text = drawingModel.Text;
//Randomly choose the font name.
FontFamily familyName = Fonts[random.Next(Fonts.Count - 1)];
// Create a new 32-bit bitmap image.
var bitmap = new Bitmap(
Width,
Height,
PixelFormat.Format32bppArgb);
// Create a graphics object for drawing.
using (Graphics g = Graphics.FromImage(bitmap))
{
g.SmoothingMode = SmoothingMode.AntiAlias;
var rect = new Rectangle(0, 0, Width, Height);
// Fill in the background.
using (var brush = new HatchBrush(
HatchStyle.SmallConfetti,
Color.LightGray,
Background))
{
g.FillRectangle(brush, rect);
// Set up the text format.
var format = new StringFormat
{
Alignment = StringAlignment.Center,
LineAlignment = StringAlignment.Center,
FormatFlags = StringFormatFlags.NoWrap | StringFormatFlags.NoClip,
Trimming = StringTrimming.None
};
format.SetMeasurableCharacterRanges(new[] { new CharacterRange(0, text.Length) });
// Set up the text font.
RectangleF size;
float fontSize = rect.Height + 1;
Font font = null;
// Adjust the font size until the text fits within the image.
do
{
if (font != null)
{
font.Dispose();
}
fontSize--;
font = new Font(
familyName,
fontSize,
FontStyle.Bold);
size = g.MeasureCharacterRanges(text, font, rect, format)[0].GetBounds(g);
} while (size.Width > rect.Width || size.Height > rect.Height);
// Check http://stackoverflow.com/questions/2292812/font-in-graphicspath-addstring-is-smaller-than-usual-font on why we have to convert to em
// Create a path using the text and warp it randomly.
var path = new GraphicsPath();
path.AddString(
text,
font.FontFamily,
(int)font.Style,
g.DpiY * font.Size / 72, rect,
format);
PointF[] points =
{
new PointF(
random.Next(rect.Width) / V,
random.Next(rect.Height) / V),
new PointF(
rect.Width - random.Next(rect.Width) / V,
random.Next(rect.Height) / V),
new PointF(
random.Next(rect.Width) / V,
rect.Height - random.Next(rect.Height) / V),
new PointF(
rect.Width - random.Next(rect.Width) / V,
rect.Height - random.Next(rect.Height) / V)
};
var matrix = new Matrix();
matrix.Translate(0F, 0F);
path.Warp(points, rect, matrix, WarpMode.Perspective, 0F);
// Draw the text.
using (var hatchBrush = new HatchBrush(
HatchStyle.LargeConfetti,
Color.LightGray,
FontColor))
{
g.FillPath(hatchBrush, path);
// Add some random noise.
int m = Math.Max(rect.Width, rect.Height);
for (int i = 0; i < (int)(rect.Width * rect.Height / 30F); i++)
{
int x = random.Next(rect.Width);
int y = random.Next(rect.Height);
int w = random.Next(m / 50);
int h = random.Next(m / 50);
g.FillEllipse(hatchBrush, x, y, w, h);
}
}
// Clean up.
font.Dispose();
}
// Set the image.
return(bitmap);
}
}
