爲我們發佈的圖片加上一個水印,也是我們經常要做的事情,那怎麼樣來做呢,下面就一步步開始吧
首先是一個製作水印的類:ImageHandler,代碼如下:
using System; using System.IO; using System.Drawing; using System.Drawing.Imaging; using System.Data; using System.Configuration; using System.Linq; using System.Web; using System.Web.Security; using System.Web.UI; using System.Web.UI.HtmlControls; using System.Web.UI.WebControls.WebParts; using System.Xml.Linq; /// <summary> ///ImageHandler 的摘要說明 /// </summary> public class ImageHandler:IHttpHandler { private const string waterMark_URL = "~/Images/waterMark.jpg"; private const string defaultImage_URL = "~/Images/Default.jpg"; public ImageHandler() { // //TODO: 在此處添加構造函數邏輯 // } public void ProcessRequest(HttpContext context) { System.Drawing.Image ImageConver; if (File.Exists(context.Request.PhysicalPath)) { //加載文件 ImageConver = Image.FromFile(context.Request.PhysicalPath); //加載水印圖片 Image waterMark = Image.FromFile(context.Request.MapPath(waterMark_URL)); //重新畫布 Graphics g = Graphics.FromImage(ImageConver); g.DrawImage(waterMark, new Rectangle(ImageConver.Width - waterMark.Width, ImageConver.Height - waterMark.Height, waterMark.Width, waterMark.Height), 0, 0, waterMark.Width, waterMark.Height, GraphicsUnit.Pixel); g.Dispose(); waterMark.Dispose(); } else { ImageConver=Image.FromFile(context.Request.MapPath(defaultImage_URL)); } //設置輸出格式 context.Response.ContentType="image/jpeg"; ImageConver.Save(context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg); ImageConver.Dispose(); context.Response.End(); } public bool IsReusable { get { return false; } } }
接下來,我們要做一個很關鍵的配置,那就是在Web.Config文件中加入如下一句話
<httpHandlers>
<!--圖片水印-->
<add verb="*" path="Images/*.jpg" type="ImageHandler"/>
</httpHandlers>