asp。net2.0 压缩图片后给图片加上水印效果

最新推荐文章于 2025-07-25 14:16:23 发布

原创最新推荐文章于 2025-07-25 14:16:23 发布 · 647 阅读

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#asp #url #null #string #class #path

<---web.config--里面要配置的文件--->

<--下面是具体加水印方法的类-->

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.IO;
using System.Drawing.Imaging;
using System.Drawing;
/// <summary>
/// CoverHandler 的摘要说明
/// </summary>
public class CoverHandler:IHttpHandler
{
    public CoverHandler()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }
    private const string WATERMARK_URL = "~/images/bg/httpHander.png";
    private const string DEFAULTIMAGE_URL = "~/images/bg/default.gif";

#region IHttpHandler 成员

    public bool IsReusable
    {
        get { return false; }
    }

    public void ProcessRequest(HttpContext context)
    {
        System.Drawing.Image Conver;
        if(File.Exists(context.Request.PhysicalPath))
        {
            //加载文件
            Conver= this.CreateThumbnail(System.Drawing.Image.FromFile(context.Request.PhysicalPath),true);
            //加载水印
            System.Drawing.Image watermark = System.Drawing.Image.FromFile(context.Request.MapPath(WATERMARK_URL));
            //实例画布
            Graphics g=Graphics.FromImage(Conver);
            //在Conver上绘制水印
            g.DrawImage(watermark,new Rectangle(Conver.Width-watermark.Width,Conver.Height-watermark.Height-100,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
            Conver = System.Drawing.Image.FromFile(context.Request.MapPath(DEFAULTIMAGE_URL));
        }
      //设置输出格式
        context.Response.ContentType="images/bg/jpeg";
        //将图片存入输出流
        Conver.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
        Conver.Dispose();
        context.Response.End();

    }
    System.Drawing.Image CreateThumbnail(System.Drawing.Image source, bool maintainAspect)
        {

            System.Drawing.Image ret = null;
            try
            {
                    int    hi = 300;
                      int wi = 300;
                // original code that creates lousy thumbnails
                // System.Drawing.Image ret = source.GetThumbnailImage(wi,hi,null,IntPtr.Zero);
                ret = new System.Drawing.Bitmap(wi, hi);
                using (Graphics g = Graphics.FromImage(ret))
                {
                    g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
                    g.FillRectangle(Brushes.White, 0, 0, wi, hi);
                    g.DrawImage(source, 0, 0, wi, hi);
                }
            }
            catch
            {
                throw;
                ret = null;
            }