Creating images on the fly in ASP.NET

Creating images on the fly in ASP.NET is pretty simple. Here is some sample code for a generic handler that can be used as a starting point for your own implementation.

<%@ WebHandler Language="C#" Class="ImageExample" %>

using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Web;

public class ImageExample : IHttpHandler
{
  public void ProcessRequest (HttpContext context)
  {
    using (Bitmap bitmap = new Bitmap(300, 200))
    using (Graphics graphics = Graphics.FromImage(bitmap))
    using (SolidBrush brush = new SolidBrush(Color.Red))
    {
      graphics.FillRectangle(brush, 0, 0, 300, 200);
      // TODO - draw your image

      context.Response.ContentType = "image/jpeg";
      bitmap.Save(context.Response.OutputStream, ImageFormat.Jpeg);
    }
  }

  public bool IsReusable
  {
    get
    {
      return false;
    }
  }
}