asp.net 图片水印经典代码

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。

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