ASP.NET中图片显示方法实例

// 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.htmlusing 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      //图片浏览次数      int numviews;      //图片数据库中的ID      int picid = Convert.ToInt32(Context.Request["id"]);      //图片路径　      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      //显示缩略图      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();        //更新数据库浏览次数        npdata.SetNumViews(picid, numviews+1);      }    }  }}