An ASP.NET Application to View and Share Photos Online

// Copyright (C) 2003 by Greg Ennis
// (mailto:greg@ennis.net)
//
// The contents of this file are subject to the Artistic License (the "License").
// You may not use this file except in compliance with the License. 
// You may obtain a copy of the License at:
// http://www.opensource.org/licenses/artistic-license.html

using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Web;
using System.IO;
using System.Configuration;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;

namespace netpix
{
	public class ImageGenerator : IHttpHandler 
	{ 
		public bool IsReusable 
		{ get { return true; } } 

		public void ProcessRequest(HttpContext Context) 
		{ 
			// Get the image filename and album root path from the database
			int numviews;
			int picid = Convert.ToInt32(Context.Request["id"]);
			string imgpath = npdata.GetPathToPicture(picid, out numviews);

			// Writing an image to output stream
			Context.Response.ContentType = "image/jpg";

			// 'thumbnail' means we are requesting a thumbnail
			if (Context.Request["thumbnail"] != null)
			{
				// Need to load the image, resize it, and stream to the client.
				// Calculate the scale so as not to stretch or distort the image.
				Bitmap bmp = new Bitmap(imgpath);
				float scale = 150.0f / System.Math.Max(bmp.Height, bmp.Width);
				System.Drawing.Image thumb = bmp.GetThumbnailImage((int)(bmp.Width * scale), (int)(bmp.Height * scale), null, System.IntPtr.Zero);
				thumb.Save(Context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg);
				bmp.Dispose();
				thumb.Dispose();
			}
			else
			{
				// Stream directly from the file
				// Get the stream and send it out the response
				System.IO.FileStream fs = File.Open(imgpath, FileMode.Open, FileAccess.Read, FileShare.Read);

				const int byteLength = 8192;
				byte[] bytes = new byte[byteLength];
				while( fs.Read(bytes, 0, byteLength ) != 0 )
				{
					Context.Response.BinaryWrite(bytes); 
				}
				fs.Close();

				// Now increment the view counter in the database
				npdata.SetNumViews(picid, numviews+1);
			}
		}
	}
}