Create Simple Captcha By Generic Handler
In this post i will create simple captcha image using generic handler.
Create new GenericHandler and write this code snippet
public void ProcessRequest(HttpContext context)
{
// Create radom number for captcha
Random rand = new Random();
int number = rand.Next(1000, 9999);
string fontSize = "30";
Font font = new Font("times new roman", float.Parse(fontSize), FontStyle.Italic);
Bitmap bitmap = new Bitmap(100,45);
Graphics graphic = Graphics.FromImage(bitmap);
// Create hatch brush
HatchBrush hatchBrush = new HatchBrush(
HatchStyle.Sphere,
Color.DimGray,
Color.LightGray);
// Fill background with DarkGray color
graphic.Clear(Color.DarkGray);
// Drawing random number
graphic.DrawString(number.ToString(), font, hatchBrush, new PointF(0, 0));
hatchBrush.Dispose();
graphic.Dispose();
// Save image to output stream
bitmap.Save(context.Response.OutputStream, ImageFormat.Gif);
bitmap.Dispose();
}
public bool IsReusable
{
get
{
return true;
}
}
{
// Create radom number for captcha
Random rand = new Random();
int number = rand.Next(1000, 9999);
string fontSize = "30";
Font font = new Font("times new roman", float.Parse(fontSize), FontStyle.Italic);
Bitmap bitmap = new Bitmap(100,45);
Graphics graphic = Graphics.FromImage(bitmap);
// Create hatch brush
HatchBrush hatchBrush = new HatchBrush(
HatchStyle.Sphere,
Color.DimGray,
Color.LightGray);
// Fill background with DarkGray color
graphic.Clear(Color.DarkGray);
// Drawing random number
graphic.DrawString(number.ToString(), font, hatchBrush, new PointF(0, 0));
hatchBrush.Dispose();
graphic.Dispose();
// Save image to output stream
bitmap.Save(context.Response.OutputStream, ImageFormat.Gif);
bitmap.Dispose();
}
public bool IsReusable
{
get
{
return true;
}
}
Code comments are clear.
for using this snippet in aspx page, you need one line code.
<img src="CaptchaHandler.ashx" />
Result is like this :
