gallerypictureshttphandler.cs

本系统是在asp版《在线文件管理器》的基础上设计制作

//------------------------------------------------------------------------------
// <copyright company="Telligent Systems">
//     Copyright (c) Telligent Systems Corporation.  All rights reserved.
// </copyright> 
//------------------------------------------------------------------------------

using System;
using System.IO;
using System.Web;
using CommunityServer.Components;
using CommunityServer.Galleries.Components;

namespace CommunityServer.Galleries.HttpHandler
{
	public class GalleryPicturesHttpHandler : IHttpHandler
	{
		public void ProcessRequest (HttpContext context)
		{
			try
			{
				int galleryID = Galleries.GetGalleryID(CSContext.Current.ApplicationKey);
				int pictureID = CSContext.Current.PostID;
				string imageType = null;
				int width = 0;
				int height = 0;
				DateTime modified = DateTime.Now;

				// See if we had width/height settings
				imageType = context.Request.QueryString["ImageType"];
				if(context.Request.QueryString["Width"] != null)
					width = int.Parse(context.Request.QueryString["Width"]);
				if(context.Request.QueryString["Height"] != null)
					height = int.Parse(context.Request.QueryString["Height"]);

				// Clear the response buffer
				context.Response.Clear();

				if(imageType == "original")
				{
					// Show the original image
					PostAttachment data = Pictures.GetPictureData(pictureID);
					modified = data.DateCreated;

					// Send the picture
					context.Response.ContentType = data.ContentType + "; name=\"" + context.Server.UrlEncode(data.FileName) + "\"";
					context.Response.AddHeader("Content-disposition", "inline; filename=\"" + context.Server.UrlEncode(data.FileName) + "\"");
					context.Response.OutputStream.Write(data.Content, 0, data.Length);
				}
				else if(imageType != null)
				{
					string filename = "";

					// Show a cached scaled image
					if(imageType == "thumb")
						filename = Picture.CacheFilename(galleryID, pictureID, GalleryImageType.Thumbnail, 0, 0);
					else if(imageType == "secondarythumb")
						filename = Picture.CacheFilename(galleryID, pictureID, GalleryImageType.SecondaryThumbnail, 0, 0);
					modified = File.GetCreationTime(filename);

					// Send the file
					context.Response.ContentType = "image/jpeg";
					context.Response.WriteFile(filename, true);
				}
				else
				{
					// Show a cached scaled image
					string filename = Picture.CacheFilename(galleryID, pictureID, width, height);
					modified = File.GetCreationTime(filename);

					// Send the file
					context.Response.ContentType = "image/jpeg";
					context.Response.WriteFile(filename, true);
				}

				// Browser cache settings
				context.Response.Cache.SetCacheability(HttpCacheability.Public);
				context.Response.Cache.SetLastModified(modified);
				context.Response.Cache.SetAllowResponseInBrowserHistory(true);
				context.Response.Cache.SetValidUntilExpires(true);
				context.Response.Cache.VaryByParams["PostID"] = true;
				context.Response.Cache.VaryByParams["Width"] = true;
				context.Response.Cache.VaryByParams["Height"] = true;
				context.Response.Cache.VaryByParams["ImageType"] = true;
			}
			catch {}
		}

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