本文实例讲述了ASP.NET中图片的显示方法。分享给大家供大家参考。具体如下：
genimage.ashx：
复制代码 代码如下:
<%@ WebHandler Language="C#" Class="netpix.ImageGenerator" %>
genimage.ashx.cs：
// 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
//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);
}
}
}
}
使用方法：
复制代码 代码如下:
imgCtrl.ImageUrl = "genimage.ashx?id=" + Request["id"];
希望本文所述对大家的ASP.NET程序设计有所帮助。
