using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Drawing; using System.IO; namespace BookShop.Web { public class WaterMark : IHttpHandler { private const string WATERMARK_URL = "~/Images/watermark.jpg"; //水印图片 private const string DEFAULTIMAGE_URL = "~/Images/default.jpg";<span style="white-space:pre"> </span> //默认图片 #region IHttpHandler 成员 public bool IsReusable { get { return false; } } public void ProcessRequest(HttpContext context) { //context.Request.PhysicalPath //获得用户请求的文件物理路径 System.Drawing.Image Cover; //判断请求的物理路径中，是否存在文件 if (File.Exists(context.Request.PhysicalPath)) { //加载文件 Cover = Image.FromFile(context.Request.PhysicalPath); //加载水印图片 Image watermark = Image.FromFile(context.Request.MapPath(WATERMARK_URL)); //通过书的封面得到绘图对像 Graphics g = Graphics.FromImage(Cover); //在image上绘制水印 g.DrawImage(watermark, new Rectangle(Cover.Width - watermark.Width, Cover.Height - watermark.Height,

watermark.Width, watermark.Height), 0, 0, watermark.Width, watermark.Height, GraphicsUnit.Pixel); //释放画布 g.Dispose(); //释放水印图片 watermark.Dispose(); } else { //加载默认图片 Cover = Image.FromFile(context.Request.MapPath(DEFAULTIMAGE_URL)); } //设置输出格式 context.Response.ContentType = "image/jpeg"; //将图片存入输出流 Cover.Save(context.Response.OutputStream, System.Drawing.Imaging.ImageFormat.Jpeg); Cover.Dispose(); context.Response.End(); } #endregion } }