asp教程.net 图片水印经典代码
防止图片被别人转载使用，我们会对图片进行水印处理。
<%@ WebHandler Language="C#" Class="BookHandler" %>
using System;
using System.Web;
using System.Drawing;
using System.IO;
public class BookHandler : IHttpHandler {
private const string COVERSADDR = "~/Image/"; //封面文件夹路径
private const string WATERMARK_URL = "~/Images/WaterMark.jpg"; //数字水印路径
private const string DEFAULT_URL = "~/Images/default.jpg"; //默认图片路径
public void ProcessRequest (HttpContext context) {
string path = context.Request.MapPath(COVERSADDR + context.Request.Params["ISBN"].ToString() + ".jpg");
Image Cover;
if (File.Exists(path))
{
Cover = Image.FromFile(path);
Image watermark = Image.FromFile(context.Request.MapPath(WATERMARK_URL));
Graphics g = Graphics.FromImage(Cover);
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);
g.Dispose();
watermark.Dispose();
}
else
{
Cover = Image.FromFile(context.Request.MapPath(DEFAULT_URL));
}
context.Request.ContentType = "image/ipeg";
Cover.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
Cover.Dispose();
context.Response.End();
}
public bool IsReusable {
get {
return false;
}
}
}
最后在页面或代码中将连接图片的路径都改成
BookCover.ashx?ISBN=数字就可以了